MRCP revision battle 15.3: Neuralgic amyotrophy

Neuralgic amyotrophy.  Never heard of it?  Me neither before today, so here are just a few facts to get you through MRCP...


Neuralgic amyotrophy is sometimes also known as brachial plexus neuropathy.


It has a particularly specific presentation:

• severe pain in shoulder
• followed by weakness and atrophy of muscles in arms

This presentation alone in an MRCP question should point you towards neuralgic amyotrophy being the answer.  Other clues which would suggest this diagnosis include:

• preceeded by a URTI
• decreased or absent reflexes
• sensory abnormalities

Rarely the diaphragm may also be affected.

There is a risk of shoulder joint subluxation or winging of the scapula.


This link takes you to an image of what just basic neuralgic amyotrophy can look like.


In general it resolves spontaneously in a few months, and treatment is conservative.




After that interesting interlude, lets do battle with the porphyrias...

MRCP revision battle 15.4: Porphyrias

Porphyrias are rare genetic disorders causing abnormalities of enzymes responsible for haem synthesis, resulting in accumulation of intermittent compounds (porphobilinogen, aminolaevulinic acid) and porphyrins.


This battle will focus on 2 acute porphyrias (acute intermittent and variegate) and 1 chronic (porphyria cutanea tarda).



1. Acute intermittent porphyria


Acute intermittent porphyria is an autosomal dominant condition in which there is a defect in porphobilinogen deaminase

Females aged 20-40 are most affected.


There is always raised urinary porphobilinogen and aminolaevulinic acid, but the rise is greater during acute attacks.  The importance of these substances is that the urine goes deep red on being left.


Signs and symptoms include:

• abdominal pain
• hypertension
• low sodium
• low potassium
• hypotonia
• psychosis
• paralysis
• seizures

Note there are NO skin symptoms.

A way to remember this list is to think of a patient saying to you "oh doctor, my abdo pain is giving me high blood pressure and stopping me being able to stand (paralysis)"... to which you may think "ah yes, you are a teaspoon (tsp = low tone, sodium, potassium) of crazy (psychosis) aren't you?"



Drugs that can precipitate acute porphyria include:

• alcohol
• benzos
• rifampicin
• tetracyclines
• phenytoin
• OCP
• halothane
• sulphonamides

Treatment is:

• remove precipitating factores
• IV fluid to correct low sodium/potassium
• high carb diet
• IV haematin
• prochlorperazine for nausea
• other symptomatic treatment

Although a rare diagnosis, porphyria should always be a differential in someone presenting with abdominal pain.



2. Variegate porphyria


This is an autosomal dominant condition characterised by a deficit in protoporphyrin oxidase.

It can cause abdominal pain and neuro symptoms, but in contrast to acute intermittent porphyria it also has a photosensitive blistering rash.


It is commoner in South Africans (afrikaans)



3. Porphyria Cutanea Tarda


This is due to uroporphyrinogen decarboxylase deficiency.


It results in a photosensitive rash with bulla.
It is also associated with hypertrichosis.
(these two factors may be the basis of werewolf legends...)


Urine has raised uroporphyrinogen which glows pink under a Woods light


Attacks are precipitated by alcohol, iron and oestrogen.



Treatment is with chloroquine.



Wow, that was quite long.  The next battle is far shorter, and is on the second condition I'd never heard of before today...

MRCP revision battle 15.5: Kearns Sayre

Kearns Sayre is an exceptionally rare condition caused by mitochondrial DNA mutations which results in:

• progressive external opthalmoplegia
• pigmentary degeneration of retina
• heart block

It may also cause proximal muscle weakness, ptosis and ataxia.
Symptoms must begin before the age of 20.


If part 2 asks what investigation you want to do, the correct answer is muscle biopsy looking for ragged red fibres.


Onwards for another brief eponymous syndrome, Klinefelters..

MRCP revision battle 15.6: Klinefelters

Klinefelters is the commonest sex chromosome disorder, affecting roughly 1 in 1000 men.

Its karyotype is 47 XXY



The key features are:

• tall stature
• small testes
• azoospermia
• gynaecomastia

 Bloods show:

• low testosterone
• high LH/FSH

Treatment is with testosterone


Note there is increased risk of OP and breast cancer.


So on to the penultimate battle of the day, pellegra...

MRCP revision battle 15.7: Pellegra

Pellegra is nicotinic acid deficiency = vitamin B3 deficiency.


Symptoms include:

• diarrhoea
• dementia
• dermatitis
• depression
• ataxia
• insomnia

(remember as in a 4d)


Causes of pellegra include:

• alcoholism
• diet
• isoniazid
• carcinoid syndrome

And we're finally about to embark on the last battle of this epic day, neuroleptic malignant syndrome...

MRCP revision battle 15.8: Neuroleptic malignant syndrome

Neuroleptic malignant syndrome is a condition that can complicate antipsychotic use. 


Its features are:

• pyrexia
• rigidity
• tachycardia

Bloods show:

• raised CK
• leucocytosis
• acidosis

It is commonest in young males, and onset is usually in the first 10 days of taking the drug or after the dose has been increased.


It is important not to miss as it has a 10% mortality.


Treatment is to stop the antipsychotic, give IV fluids, dantrolene and ?bromocriptine.



That's all for today, I'll catch up on the 'wars' tomorrow after I've caught up on sleep!

MRCP revision battle 14.1: Schistosomiasis

Its a very random bag today, with our first adventure in the world of infectious diseases, some clotting-based battles in the arena of haematology then a tricyclic overdose to round it all off!


MRCP revision battle 14.1: Schistosomiasis
MRCP revision battle 14.2: The clotting cascade
MRCP revision battle 14.3: Factor V Leiden
MRCP revision battle 14.4: Thrombocytopenia
MRCP revision battle 14.5: ITP
MRCP revision battle 14.6: TCA overdose



MRCP revision battle 14.1: Schistosomiasis

Warning... this is a revision topic likely to make you itch...


Schistosomiasis is a parasitic disease caused by flukes (=trematodes.)   It is generally carried by snail vectors that release cercariae (= parasitic lavae)

The first sign of infection may be 'swimmers itch'.  The MRCP exam may give a history of a patient who has been on holiday to Asia/Africa/South America and has been swimming in a river and is now itchy with a rash.  In part 2 there may also be a picture like the one below:

The rash tends of appear within hours of infection and disappear within a week.



The classical presentation of acute schistosomiasis itself occurs roughly 2 weeks after infection with:

• fever
• urticaria
• diarrhoea
• abdominal pain
• cough
• hepatosplenomegaly

This acute version of schistosomiasis is known as Katayama Fever


The treatment is praziquantel.


If schistosomiasis is not recognised and treated it can become a chronic granulomatous disease (granulomas form around the schistosomiasis eggs).  Which parts of the body are affected depends on the type.  For the purposes of MRCP the following associations are worth learning:

• s.mansoni - liver disease, transverse myelitis
• s.japonicum - liver disease
• s.haematobium - urinary tract/bladder disease (haematuria)
• --> increased risk of squamous cell carcinoma of bladder

The most practical way of diagnosing is by looking for eggs in stool/urine.


It goes without saying that any question with an eosinophillia in the blood results of someone who has been travelling should raise the possibility of this as a diagnosis.



Now on to the less exotic world of haematology and a recap of the clotting cascade!

MRCP revision battle 14.2: The clotting cascade

Before we start tackling clotting disorders a recap of the clotting cascade would be useful.


A schematic of the clotting cascade is:

Its really important to get this in your head as various questions are likely to be indirectly testing your knowledge of it.  I remember the intrinsic pathway into the common pathway as by a little jingle of     " 12,11,9 then 10 (pause) 2, 1 then back again " with the 'back again' bit referring to factor 13 getting in on the action right at the very end to stablise the clot and hence the numbers returning back to being higher.

Also note where VIIIa and Va are involved.



Now look at the same schematic again but with the addition of activated protein C and antithrombin:

So as well as learning the cascade itself make sure the following are etched in your brain:

• activated protein C inhitbits VIIIa and Va
• antithrombin inhibits Xa and IIa 
• protein C is converted to activated protein C by protein S        and finally
• factors II, VII, IX, X are vitamin-K dependent (method of remembering: '1972')

With all that groundwork covered, lets  move on to battle 14.3 and put a bit of it into practice.

MRCP revision battle 14.3: Factor V Leiden

A point mutation on the gene for clotting factor V results in a varient known as 'factor V Leiden'.
It is inherited in an autosomal dominant fashion.


The result of the mutation is that factor V is insensitive to protein C inactivation, resulting in hypercoagulability.


This leads to increased risk of PE/DVTs and in females increased miscarriage.


Merely being factor V leiden positive doesn't necessitate anticoagulation; warfarin etc would only be considered in response to events rather than prophylactically - indeed, up to 7% of all white europeans/north americans have factor V leiden, making it the commonest inherited thrombophilia.



So having looked at a cause of thrombophillia, lets switch to the opposite and consider low platelets...

MRCP revision battle 14.4: Thrombocytopenia

Thrombocytopenia refers to low numbers of platelets.
Generally the lower limit of normal for platelets is 150 000, with thrombocytopenia often defined as <50 000.


Low platelets increase the risk of bleeding/bruising, commonly manifesting as bleeding gums or nose bleeds.


Causes of thrombocytopenia can be broadly divided into causes that increase platelet destruction and causes that decrease production:

1. increased platelet destruction (= DISC HH)
• DIC
• ITP
• SLE
• CLL
• Heparin
• Hypersplenism (portal hypertension, leukaemia)
2. decreased platelet production (=CAB M)
• Chemo/radiotherapy
• aplastic anaemia
• B12/folate deficiency
• marrow infiltration

Isotretinoin and valproic acid have also been associated with thrombocytopenia.


Treatment is dependent on the cause/the symptoms.



Onwards to the last haematological battle of the day, ITP...

MRCP revision battle 14.5: Idiopathic Thrombocytopenia Purpura

ITP is a condition which results in low numbers of platelets.  Despite its title of 'idiopathic' it is often autoimmune mediated, with IgG autoantibodies against glycoprotein IIb/IIIa/Ib complex.


Acute ITP:

• affects mainly children
• boys and girls equally affected
• often after infection/vaccination
• tends to be self-limiting over 2 weeks

Chronic ITP:

• females >males
• relapsing-remitting

In ITP the bone marrow shows megakaryocytes


Treatment is only needed if the patient is symptomatic or the platelets are <20.
First line = oral prednisolone - 80% respond
If no response in 3 months --> splenectomy
Other options include IV IG or immunosupressive drugs.



One random MRCP type syndrome: Evan's syndrome = ITP +AIHA.


Nearly there, just a quick tricyclic overdose to go...

MRCP revision battle 14.6: TCA overdose

Lets end the day (and the working week) on an overdose.  I've always found it somewhat ironic (and at times in A&E irritating) that a medication which you give to depressed people to treat their depression is so incredibly dangerous in overdose...



TCA in overdose produce symptoms due to their:

• anticholinergic effects (dry mouth, dilated pupils, tachycardia, constipation, urinary retention, raised intraocular pressure)
• alpha blockade (hypotension)
• sodium channel blockade (my personal favourite, cardiac arrhythmias)

On the ECG look out for:

• long PR
• wide QRS
• long QT

In terms of managing these patients you need:

• ECG and cardiac monitoring
• consider charcoal if <2 hrs post ingestion
• bloods for UEs and paracetamol and salicylate (always assume paracetamol taken until proven otherwise)
• ABG
• fluids if needed to support BP
• if acidotic - bicarb
• dialysis is NOT indicated
• avoid class Ia/Ic/III antiarrythmics as they all prolong QT.  Also avoid flumazenil (also prolongs QT)
• observe

Thats all for today folks, and I'm taking tomorrow off.  And possibly the day after too, depending on my mood.  But battles will definitely recommence on Monday.

MRCP revision battle 13.1: Brugada Syndrome

I'm afraid I'm too tired to even attempt an insightful intro today so lets just go straight to listing the battles:

MRCP revision battle 13.1: Brugada Syndrome
MRCP revision battle 13.2: SVC obstruction
MRCP revision battle 13.3: Causes long PR
MRCP revision battle 13.4: Cauda equina syndrome
MRCP revision battle 13.5: Surviving Sepsis





MRCP revision battle 13.1: Brugada Syndrome


Brugada Syndrome is an autosomal dominant condition that causes abnormal sodium channel proteins, leading to a risk of VF/VT and sudden death.


It is commonest in Asians.

20-40% of cases are associated with a SCN5A mutation.


ECG shows partial/complete RBBB with ST elevation in V1 to V2.  The classical ECG is type 1 below, with the other 2 possible variations.

 Treatment is ICD.


Next up - SVC obstruction...

MRCP revision battle 13.2: SVC obstruction

SVC obstruction can be frightening for the doctor as well as the patient - the first lady I saw with it came in with a lovely slim face and as time went on it became more and more puffy and she became increasingly dyspnoeic.  Once seen it will never be forgotten; I can post this photo:

                                                                     Herbert L. Fred, MD and Hendrik A. van Dijk, Wiki Commons

which demonstrates the type of difference I saw in my patient (normal on right, SVC on left).  My patient however was female and smiled more!


Anyway, lets refocus on points to learn for the MRCP exam:


Features of SVC obstruction:

• dyspnoea
• orthopnoea
• headache 
• cyanosis
• cough
• swollen face/arm
• engorged veins

There is a rather nice test called Pemberton's Test which involves asking the patient to lift their arms above their head for >1 min and watch for increasing plethora/cyanosis, raised JVP and listen for stridor (that sound every doctor wants to induce in their patient...)  If these things occur it is a positive Pembertons test and suggestive of SVC obstruction.



Causes of SVC obstruction include:

• lung cancer
• lymphoma
• thymus malignancy
• thrombus around central line

Treatment is surgical, with dexamethasone whilst awaiting this.



Lets return to the small-squared world of the ECG to consider causes of a long PR...

MRCP revision battle 13.3: Long PR interval

The PR interval represents the time taken for the electrical impulse to travel from the sino-atrial node and through the atrioventricular node to the ventricles.

Normal range is 0.12 to 0.2 milliseconds (= 3 to 5 small squares)

A long PR = first degree heart block.


Causes of a long PR ( can be remembered as DRIP SAL, easier to remember if you have a drippy friend called Sally):

• Drugs (beta blockers, calcium channel blockers, digoxin)
• Rheumatic fever
• IHD (anterior MIs in particular can prolong the PR interval)
• Potassium - either high or low levels
• Sarcoidosis
• Aortic root pathology
• Lyme disease

So that was short and sweet.  Onto another brief battle that should be familiar, cauda equina syndrome...

MRCP revision battle 13.4: Cauda Equina Syndrome

Cauda equina syndrome refers to a set of features caused by compression of the cauda equina.

The cauda equina begins in most people at around L1/L2.



Features of cauda equina syndrome include:

• low back pain
• sciatica
• urinary incontinence/retention
• faecal incontinence/retention
• variable motor/sensory loss
• classically saddle/perianal paraesthesia

Causes of cauda equina are logical when you think about it, you just need to consider what could be there to press on it:

• commonest = large central disc herniation at L4/L5 or L5/S1
• tumours
• trauma
• epidural abscess (consider this one in MRCP questions that mention a 'post op patient')
• post op haematoma (another reason to look out for that 'post-op patient')
• IVC thrombus
• ankylosing spondylitis
• sarcoidosis

Treatment is urgent surgery.


So to the final (and juiciest) battle of the day, surviving sepsis...

MRCP revision battle 13.5: Surviving sepsis

There has been a concerted push in recent years to improve the prognosis of patients presenting with sepsis, led by the international 'Surviving Sepsis' campaign.  But what are the key points to pick up for MRCP?


Firstly, a few definitions.


SIRS = systemic inflammatory response = 2 or more of:

• temperature >38 or <36
• WCC >12 or <4
• RR>20 or pCO2 <4.3
• pulse >90 (note this is lower than you'd probably have expected)

Sepsis is then defined as SIRS plus infection.


Severe sepsis is then defined as sepsis with evidence of organ dysfunction (hypoxia, anuria, raised lactate... so many possible options for the evidenve)

And then septic shock is defined as severe sepsis plus hypotension.


Now we know what sepsis is, what are the key messages from the surviving sepsis campaign?

1. resuscitate

• if hypotensive or lactate >4 give fluids

• aim 
• CVP 8-12mmHg
• MAP>65
• urine output >0.5mls/kg/hr
• central venous O2 >70% or mixed venous >65%
• if fluid alone not achieving goals, consider:
• packed RBC to haematocrit >30% or
• dobutamine infusion

1.  =
2. give antibiotics
3. keep MAP >65mmHg
1. norepinephrine 
2. dopamine
4. consider hydrocortisone if fluids and vasopressors aren't working
5. consider recombinant human activated protein c 
• if apache >25 or multiple organ failure
6. remember DVT prophylaxis
7. consider peptic ulceration prophylaxis

As Bugs Bunny would say, thaatts all folks... unless you fancy participating in today's war to check your recall of yesterday's topics...

MRCP questions: War 12

As with previous 'wars' after 'battles' these are just a few quick questions to see if your brain cells have retained the information provided in battles 11.1 to 11.4.

Grab a piece of paper, jot down your answers then compare them to my answers here


Question 1:
Which atria are atrial myxomas found in 75% of the time?


Question 2:
What murmur is associated with aortic dissection?


Question 3:
What % of patients with aortic dissection will have a pulse deficit?



Question 4:
What is the commonest form of aortic dissection?



Question 5:
How are type A dissections managed?



Question 6:
What is the classic cell associated with CLL on blood film?

Question 7:
List 5 features that suggest a poorer prognosis in CLL


Question 8:
What condition does tartrate resistant acid phosphatase positive suggest?



Question 9:
What is Richters syndrome?



Question 10:
How often is the mediastinum wide on a CXR if the patient has aortic dissection?



The answers are here

MRCP revision battle 13

                   
               

MRCP revision battle 13

                   
               

MRCP revision battle 12.1: Atrial myxoma

Today's battles are a mixed bag; usually they are generated from past questions I've done while today's bunch include some motivated by gaps in clinical knowledge revealed during a recent take.  So the battles are:

MRCP revision battle 12.1: Atrial Myxoma
MRCP revision battle 12.2: CLL
MRCP revision battle 12.3: Hairy cell leukaemia
MRCP revision battle 12.4: Aortic dissection


MRCP revision battle 12.1: Atrial Myxoma

Atrial myxoma are usually benign tumours found in the atria.
75% are in the left atrium.

0.3% of the population are found to have an atrial myxoma at post mortem.
Females >males, 2:1


Atrial myxoma are usually sporadic but an autosomal dominant inheritance also exists.


They are usually benign but as they grow rapidly and embolise they require surgery.



Features of atrial myxoma include:

• clubbing
• weight loss
• fever
• AF
• emboli
• mid diastolic murmur - an 'atrial plop'

Investigations may show:

• raised wcc
• low platelets
• raised ESR in 60%

After that brisk whizz through atrial myxoma, onward to CLL!

MRCP revision battle 12.2: CLL

I keep clerking patients who say they've got 'CLL, doctor' and I nod sagely and scribble it down, while desperately trying to recall any of my med school haematology lectures.  My brief summary for MRCP means that now hopefully my sage nod is slightly more appropriate!!



CLL (=chronic lymphocytci leukaemia) is a monoclonal proliferation of mature lymphocytes.

99% of cases of CLL involve B cells.

CLL is important clinically as it is the commonest cause of lymphocytosis in the elderly.
Males are more often affected than females, 2:1



Presentation:

• no symptoms in 25%
• recurrent infections (due to hypogammaglobulinaemia)
• anaemia (warm AIHA in 10-15%)
• decreased weight
• sweats
• anorexia

Signs includer:

• enlarged rubbery, non-tender nodes
• hepatomegaly
• splenomegaly

Blood tests will show:

• raised lymphocytes
• low Hb, neutrophils and platelets
• smear/smudge cells on blood film

Staging is done by the Rai classification, which can also be used to give the prognosis:

• Stage 0 - lymphocytosis alone - mean survival >13 yrs
• Stage 1 - lymphocytosis plus lymphadenopathy - mean survival 8 yrs
• Stage 2 - lymphocytosis plus spleno/hepato megaly - mean survival 5 yrs
• Stage 3 - lymphocytosis plus anaemia (defined as Hb <11) - mean survival 2 yrs
• Stage 4 - lymphocytosis plus platelets <100 - mean survival 1 yr

Indicators of poorer prognosis include:

• being male
• age >70
• lymphocytes >50
• prolymphocytes >10%
• doubling rate <12 months
• raised LDH
• CD 38 positive
• ZAP 70 + (if ZAP 70 -ive, mean survival 25 years)

Management of CLL is:

1. monitoring only if asymptomatic
2. chlorambucil to decrease lymphocyte count, improve marrow function and decrease node size
3. fludarabine (a chemo agent, purine analog that works by inhibiting DNA synthesis) if:
• bulky disease
• cytopenias due to marrow failure
• short lymphocyte doubling time

CLL may transform to Richters syndrome.
Richters syndrome is the transformation of CLL to agressive B cell lymphoma.  LDH is raised.



Now onwards to a subtype of CLL, hairy-cell leukaemia.

MRCP revision battle 12.3: Hairy Cell Leukaemia

Hairy cell leukaemia is a subtype of CLL characterised by (suprise, suprise) cells that appear 'hairy' on microscopy.


Hairy cell leukaemia is 4 times more common in men than women.


Features of hairy cell leukaemia include:

• pancytopenia
• splenomegaly
• skin vasculitis in 1/3 cases
• 'dry tap' 

A key phrase to look out for in MRCP is 'tartrate resistant acid phosphatase positive'


Treatment of hairy cell leukaemia is chemotherapy.  Second line options include alpha interferon and rituximub.


Thats quite enough haematology for one day... lets move on for a 'rippingly' good time with aortic dissection...

MRCP revision battle 12.4: Aortic dissection

Aortic dissection is a scary condition with a mortality rate of 1% per hour.  But before we jump into it, lets begin with a quick recap of some basic anatomy.

The layers of the aorta are, from inside out:

• tunica intima = epithelial cells
• tunica media = smooth muscle and elastic fibres
• tunica adventitia = connective tissue

Aortic dissection usually involves blood collecting in the media.


The aorta itself leaves the heart, goes up into an arch and then down again, giving off branches as it goes.  The picture below shows the vessels coming off the aorta:

 

1 indicates the ascending aorta, 2 the brachiocephalic trunk, 3 the right subclavian artery, 4 the right common carotid, 4 the right common carotid, 5 the left common carotid and 6 the left subclavian artery.

A knowledge of this anatomy aides understanding of the signs and symptoms of aortic dissection.

So what are the features of an aortic dissection?

• sudden onset of 'tearing' or 'ripping' pain
• if pain intrascapular, likely a descending dissection
• MI
• stroke
• parathesia of arms
• hemiparesis
• many others, depending on the part of the aorta affected

Signs to look out for include:

• aortic regurgitation - present in 1/3 ascending dissections
• pulse deficit in an arm - present in 15%
• BP difference in arms >20mmHg (but note 'normal' individuals may have a BP difference)

Aortic dissections may be classified using either the Stanford or DeBakey systems:

• Stanford A = ascending dissection - accounts for 2/3 of dissections
• this covers DeBakey I - ascending and descending aorta involved and
• DeBakey II - ascending aorta only involved
• Stanford B = descending aorta only dissected (distal to left subclavian artery) - accounts for 1/3 of dissections
• = DeBakey III

 Management of aortic dissection:

• if type A - IV labetalol and urgent surgery
• if type B - IV labetalol only

Complications associated with type A dissections include:

• aortic regurgitation
• inferior MI
• pericardial effusion
• carotid dissection
• loss of pulses

Investigations for dissection:

• CXR 
• shows widened mediastinum in 70% of cases
•  Ring sign - calcification of aorta with wall displaced >5mm
• CT
• TOE

Risk factors for dissection include:

• hypertension (80%)
• Marfans
• Noonans
• Turners
• trauma
• pregnancy
• coarctation
• congenital bicuspid valve
• giant cell artertitis
• cocaine use

If you feel motivated to read more, I'd recommend this webpage: http://www.aorticdissection.com/Aortic%20Diagnosis.htm


A 'war' for yesterday's questions is here

MRCP questions: War 11

As with previous 'wars' after 'battles' these are just a few quick questions to see if your brain cells have retained the information provided in battles 10.1 to 10.6.

Grab a piece of paper, jot down your answers then compare them to my answers here

Question 1
List 4 factors that lead to a worse prognosis in GBS.

Question 2
What percentage of patients with GBS will make a complete or near complete recovery?



Question 3
What regular investigation do patients with GBS require?


Question 4
What is the classic triad of Miller-Fisher syndrome?



Question 5
What antibodies are usually associated with Miller-Fisher syndrome?



Question 6
What is syringomyelia?


Question 7
What are the cardinal symptoms of syrinomyelia?


Question 8
What is the inheritance of Kallmans syndrome?



Question 9
List 5 symptoms/signs of carcinoid syndrome



Question 10
What is the treatment of carcinoid syndrome?


answers here

MRCP revision battle 11.1: Guillain Barre Syndrome

When you're working 12 hr days (plus commute) fitting in revision can feel a bit like trying to squeeze that extra towel into the suitcase - you may manage it, but the suitcase is then stretched and prone to snap open at unfortunate times.  If you extend this metaphor to the suitcase being your sanity it explains why junior doctors can often become more emotionally incontinent/irrational as MRCP exams get nearer.  So whats the solution?  Well, in the suitcase scenario you'd add some of those rubber bands round to keep it closed.  In real life, your friends, family and managing to keep some form of hobby/interest going are your rubber bands.

Since I don't want to overpressure my 'rubber bands' I'm going to limit today's battles to

MRCP revision battle 11.1: Guillain Barre Syndrome
MRCP revision battle 11.2: Miller Fisher Syndrome
MRCP revision battle 11.3: Syringomyelia
MRCP revision battle 11.4: Kallmans
MRCP revision battle 11.5: Carcinoid Syndrome






MRCP revision battle 11.1: Guillain Barre Syndrome


Guillain Barre Syndrome is a rare, post-infective demyelinating polyneuropathy.


It tends to occur a few weeks after 'the flu' or a minor illness.  The most commonly associated pathogens are:

• campylobacter jejuni
• mycoplasma
• CMV
• EBV
• HIV
• zoster

Guillain Barre Syndrome is characterised by an ascending, symmetric muscle weakness.  Proximal muscles are more affected than distal ones.  Cranial nerves may also be involved, with CN VII being the most common.


There is usually a 'progressive' phrase for around 4 weeks, after which the patient starts to improve.


Features associated with GBS that appear in MRCP questions include:

• papilloedema
• urinary retention
• arrhythmias

Diagnostically GBS is characterised by:

• very high protein in CSF
• decreased nerve velocity on EMG
• areflexia

The prognosis for patients with GBS is worse if:

• rapid onset of symptoms
• older age
• axomal neuropathoes
• preceeded by campylobacter infection

Management is:

• 4 hourly FVC, to check the patient's respiratory muscles aren't affected
• ventilation if needed
• plasma exchange
• IV IG

Overall, 85% of patients make a complete/new complete recovery.
10% will relapse
Less than 5% will die.


Now to to meet a close relative of GBS, Miller Fisher Syndrome.

MRCP revision battle 11.2: Miller Fisher Syndrome

Miller Fisher Syndrome is essentially a rarer variant of Guillain Barre Syndrome.


It's classical triad is:

• areflexia
• ataxia
• opthalmoplegia

Anti-ganglioside antibodies, especially to GQ1b, will be positive in 90% of cases.


On to syringomyelia...

MRCP revision battle 11.3: Syringomyelia and Syringobulbia

Syringomyelia and syringobulbia have always confused me, partly because for some reason I even have problems pronouncing their names!  However, in terms of MRCP there isn't too much you need to know...


Syringomyelia is a cyst/cavity forming in or close to the central canal of the spinal cord.


The cause may be anything that is hindering CSF circulation, but the classical cause is an Arnold Chiari malformation (=condition where the cerebellum herniates through the foramen magnum.)


The essential features are:

• wasting and weakness of muscles of the hands (possibly 'claw hand')
• loss of pain and temperature sensation in hands

Other possible signs/symptoms are varied and include Horner's syndrome, eye movement abnormalities and UMN signs in the legs.


Treatment is surgery.


If the cavity/cyst extends from the cord into the brain stem it is known as syringobulbia and causes bulbar palsy type symptoms, facial pain and dizziness.



After that neurology binge onto a slightly lighter topic, Kallmans...

MRCP revision battle 11.4: Kallmans

Kallmans syndrome is an x-linked recessive condition caused by failure of GnRH secreting neurones to migrate to the hypothalamus.


Its features are:

• anosia
• 'delayed puberty'
• hypogonadism, crytoorchidism
• may be tall or of normal height

Investigations: blood LH/FSH/testosterone and all either normal or low


The most important complication to remember for MRCP is the increased risk of osteoporosis

Next up: Carcinoid syndrome

MRCP revision battle 11.5: Carcinoid Syndrome

Carcinoid tumours are common - 1% of the population will have one at post mortem.

They primarily secrete serotonin (5HT) but may also produce histamine/adrenal hormones/insulin...


45% of carcinoid tumours are in the appendix and a further 30% in the ileum.
They can cause complications such as appendicitis, obstruction or intussception.


Having said carcinoid tumours are common, it's important to understand that carcinoid syndrome is rare - it only occurs when the liver is involved, as tumours in other places will have their 5HT metabolised rather than it have an effect.


Features of carcinoid syndrome are:

• flushing
• diarrhoea
• bronchospasm
• pellegra
• hypotension

Diagnosis is by:

1. urinary 5-HIAA
2. plasma chromograffin - the new way which, depending on the leve,  also gives an indication of the mass of tumours

Treatment is:

• surgery
• ocreotide

Survival from diagnosis tends to be 5 to 8 years.
Patients with carcinoid heart disease have a worse prognosis.


It is also worth remembering that if these tumours are over-handed (eg during surgery) or out-grow their blood supply, a massive 'hormone hit' can be released in one go, causing a carcinoid crisis.


Features of a carcinoid crisis:

• vasodilation
• hypotension
• tachycardia 
• bronchoconstriction
• hyperglycaemia 

So those are today's battles fought, and hopefully won.  Click here if you want to partake of the 'war' of questions to check your recall of yesterday's topics.

MRCP questions: War 10

As with previous 'wars' after 'battles' these are just a few quick questions to see if your brain cells have retained the information provided in battles 9.1 to 9.6.


Grab a piece of paper, jot down your answers then compare them to my answers here

Question 1:
What are the diagnostic criteria for hereditary haemorrhagic telangiectasia?


Question 2:
List 3 possible causes of increased shortness of breath on sitting up compared to lying down.



Question 3:
Which form of MND affects only LMN?


Question 4:
Name the only drug treatment available for MND

Question 5:
List 5 causes of bulbar palsy


Question 6:
What condition is associated with a 'Donald Duck' voice?



Question 7:
Which genetic condition causes an increase in uric acid levels?


Question 8:
List 5 causes of low voltage ECG complex


Question 9:
What causes electrical alternans on ECG?



Question 10:
How is multifocal motor neuropathy treated?


answers here

MRCP revision battle 10.1: Hereditary Haemorrhagic Telangiectasia

Once again I can see a sunny day... through the window my desk sits in front of.  Although today I've found the sun a catalyst for working rather than a mocking presence as my lovely other half has promised me a picnic later, so the sooner I finish the sooner I get jam sandwiches!

Today's topics are:

MRCP revision battle 10.1: Hereditary haemorrhagic telangiectasia
MRCP revision battle 10.2: Motor Neurone Disease
MRCP revision battle 10.3: Bulbar Palsy
MRCP revision battle 10.4: Pseudobulbar palsy
MRCP revision battle 10.5: Multifocal Motor Neuropathy
MRCP revision battle 10.6: Lesch-Nyhan Syndrome
MRCP revision battle 10.7: Low voltage ECG complexes

I promise that's less than it looks...



MRCP revision battle 10.1: Hereditary haemorrhagic telangiectasia


Hereditary haemorrhagic telangiectasia (HHT), also known as Osler-Weber-Rendu syndrome, is an autosomal dominant condition associated with abnormal blood vessel formation.


Features of HHT include:

• telangiectasia on skin
• telangiectasia on mucosal membranes (leading to nose bleeds/GI bleeds)
• arterio-venous malformations (AVMs)
• commonest in lung
• also in liver
• brain
• spine (rarest)

The diagnostic criteria are:

1. spontaneous and recurrent nosebleeds
2. telangiectasia
3. AVMs
4. positive family history - a first degree relative

The international consensus  states if 3 or 4 of the above features are present HHT is definite.  If 2 are present it is possible.  Less than that is unlikely.


A rare symptom the MRCP exam may throw up is platypnoea, which is difficulty breathing when sitting up/standing which is relieved on lying down.  Platypnoea is therefore the direct opposite of orthopnoea!  To briefly diversify, apart from lung AVM two other possible causes of platynoea are left atrial tumour or left atrial thrombus.


A rare sign associated with lung AVM is a 'humming sound' on auscultation over that area of the chest.


Management of HHT is symptomatic.



After that forray into the world of bleeding bits we're about to dive into the murky world of neurology with motor neurone disease...

MRCP revision battle 10.2: Motor Neurone Disease

Most people associated motor neurone disease (MND) with Stephen Hawking, that incredible physicist who has lived with MND for over 40 years.  However, in the same way he is not a stereotype for normal intelligence he is also not a stereotype for MND - most people with it die within 5 years.  More stereotypical for the course of the disease was Lou Gehrig, an American baseball player in the 1920s/1930s who was diagnosed with the disease and died within 3 years.  I mention him not just for random interest but also because in America MND is sometimes known as Lou Gehrig disease.  But what is MND?


MND is a group of neurological disorders affecting neurones in motor cortex, CN nuclei and anterior horn cells.


MND affects UMN and LMN but there is no sensory involvement.


As a quick recap, UMN signs include:

• weakness
• spasticity
• brisk reflexes
• upgoing plantars

LMN signs include:

• weakness
• wasting
• fasciculation
• depressed reflexes

There are several patterns of MND, including:

1. Amyotrophic lateral sclerosis
• presents as UMN signs in legs and LMN signs in arms
• may be familial - in which case often associated with Ch 21
• accounts for 50% of cases of MND
• has an 'intermediate' prognosis
2. Bulbar palsy
• accounts for around 25% of cases of MND
• has the worst prognosis of the presentations
• more details in the next battle
3. Progressive muscular atrophy
• only LMN affected
• begins distally
• has a (relatively) good prognosis
4. Primary lateral sclerosis
• affects UMN only

10-35% of patients with MND will have fronto-temporal dementia.


Diagnosis of MND is primarily clinical.
EMG will show preserved motor conduction velocities
CSF analysis may show raised protein.


Treatment is with riluzole, which prolongs life by around 3 months and requires monitoring of LFTs.  There is no cure.

As the first paragraph stated, the prognosis is very poor and most patients are dead within 5 years.




So on to battle 10.3, to learn more about bulbar palsy.

MRCP revision battle 10.3: Bulbar Palsy

Bulbar palsy refers to palsy of the nerves coming from the 'bulbar' part of the brain, ie the pons, medulla and cerebellum.  These are VII, VIII, IX, X, XI and XII.


Classically bulbar palsy presents as palsy of tongue, muscles of chewing and swallowing and facial muscles.


Signs are LMN:

• flaccid tongue
• fasciculating tongue
• absent or normal jaw jerk
• loss of gag reflex
• quiet/horse voice

Causes of bulbar palsy include:

• MND
• syringobulbia (more about this condition tomorrow!)
• GBS (also lined up for battle tomorrow)
• polio
• Lyme disease
• brain-stem tumours

Next up: battle 10.4, pseudobulbar palsy

MRCP revision battle 10.4: Pseudobulbar palsy

Pseudobulbar palsy is a UMN palsy of the muscles affecting eating, swallowing and talking above the midpons.


Signs are:

• spastic tongue
• brisk jaw jerk
• emotional incontinence
• 'Donald Duck' voice.

Causes include:

• MS
• MND
• PD
• stroke
• high brain stem tumour

Just one more skirmish with neurology to go today, in the form of multifocal motor neuropathy.

MRCP revision battle 10.5: Multifocal motor neuropathy

I must confess I'd never come accross multifocal motor neuropathy until I started doing MRCP questions, but I'm now rather glad that I have, as essentially it is a treatable differential diagnosis for some presentations that appear like MND (which, as we've just covered, is nasty and deadly)


Multifocal motor neuropathy is an acquired immune-mediated demyelinating neuropathy.


Features of multifocal motor neuropathy include:

• slowly progressive, asymmetric distal muscle weakness
• cramps and twitching
• no sensory loss
• no/minimal muscle atrophy
• possibly positive anti GM1 antibodies (NB also + in GBS)
• no UMN signs
• normal or decrease tone
• absent reflexes

The joy of multifocal motor neuropathy is that it can be successfully treated with IV IG!


Well thats quite enough neurology for today, lets now look briefly at Lesch-Nyhan Syndrome, as promised yesterday

MRCP revision battle 10.6: Lesch-Nyhan Syndrome

Lesch-Nyhan Syndrome is a rare inherited x-linked disorder caused by an abnormality of an enzyme involved in purine metabolism resulting in increased uric acid.  Only boys tend to be affected.


Features of Lesch-Nyhan Syndrome include:

• orange crystals in nappies
• low IQ
• self-mutilation
• fits
• recurrent gout (probably the most important relationship to remember in MRCP)
• megaloblastic anaemia

Patients usually die by the age of 25, often of renal failure.


So to the final battle of the day, a nice gentle ending with a breeze through the causes of low-voltage complexes on ECG

MRCP revision battle 10.7: Causes of low-voltage complexes on ECG

'Low voltage complex' on ECG is defined as:

• QRS amplitude <5mm in all limb leads and/or
• QRS amplitude <10mm in all chest leads

The causes of low voltage complexes can be split into 2 main groups: increased distance from leads to heart or infiltrative disease of heart.

Using these divisions:

1. increased distance from leads to heart:
• emphysema/COPD
• pericardial effusion
• severe obesity
• pleural effusion
2. infiltrative disease of heart/problems with heart itself: 
• amyloid
• haemochromatosis
• cardiomyopathies
• global ischaemia

Myxoedema can also cause low complex ECGs but my search for why this is (?caused by myxoedema or ?caused by effects of myxoedema) proved fruitless... please let me know if you have the answer!



If you see an ECG with alternating normal complexes and low-voltage complexes, you are looking at electrical alternans which tends to be a sign of pericardial effusion/cardiac tamponade.  Click here to see an image of it.


So today's battles are over.  If you want to undertake the war to see how much of yesterday's battles you recall, please click here 

MRCP questions: War 9

As with previous 'wars' after 'battles' these are just a few quick questions to see if your brain cells have retained the information provided in battles 9.1 to 9.5.


Grab a piece of paper, jot down your answers then compare them to my answers here


Question 1:
Name the classical rash associated with Lyme disease


Question 2:
What is the treatment for uncomplicated Lyme disease?



Question 3:
A joint aspiration shows negatively birefrigent crystals.  What condition does this suggest?



Question 4:
What XR appearance may you see in gout?



Question 5:
Which joint is classically affected by pseudogout?



Question 6:
What is a craniopharyngioma?



Question 7:
What is a catamenial pneumothorax?

.


Question 8:
What is Hammans sign?  What does it signify?



Question 9:
A 19 yr old boy presents with shortness of breath.  A CXR shows a 3cm rim of air around his left lung.  How would you manage him?



Question 10:
You have a patient with a painful joint and the XR shows chondocalcinosis.  What condition does this suggest?



answers here

MRCP revision battle 9.1: Lyme Disease

Working and revising really does feel rather relentless.  I keep thinking of the pop song "and the beat goes on..." - somehow it seems appropriate for the continuous dedication work plus MRCP revision requires!  Anyway, what revision battles does today bring?

MRCP revision battle 9.1: Lyme disease
MRCP revision battle 9.2: Gout
MRCP revision battle 9.3: Pseudogout
MRCP revision battle 9.4: Craniopharyngioma
MRCP revision battle9.5: Pneumothorax




MRCP revision battle 9.1: Lyme disease

Lyme disease, named after the place in America where the condition was first noted, is a condition caused by the spirochaete borrelia burdorferi.  


It is spread by tic bites, with certain areas (such as northern America) being higher risk than, for example, Surrey.  However, it is found in the UK and it is important to note the majority of patients will not remember the bite itself.




Signs, symptoms and complications associated with Lyme disease are multitude and vague, including:

• malaise
• fever
• muscle pain
• joint swelling
• decreased cognition
• encephalitis
• meningitis
• lymphadenopathy
• cranial nerve palsies (MRCP likes bilateral facial nerve palsy for some reason)
• neuropathy
• skin conditions

The classical skin condition associated with Lyme disease is erythema chronicum migrans, which is a spreading erythematous rash which then clears centrally but leaves a spot in the middle (click here for a picture).




A rarer skin condition is acrodermatitis chronica atrophicans, which occurs late in infection and eventually results in atrophic skin that is thin like cigarette paper.




Another rarer skin manifestation is borrelial lymphocytoma, which is a blue-red discoloration of the ear lobe.


Investigation is usually ELISA/PCR.
If the question throws in a CSF sample look for slightly raised protein and lymphocytosis.



Treatment of the rash only is doxycycline.  More serious disease may require IV ben pen/a 3rd generation cephalosporin. 



There is of course far more to learn about Lyme disease should you be so inclined, but if you're content with the barer MRCP-bones of it lets move on to battle 9.2, gout.

MRCP revision battle 9.2: Gout

Ah Gout... that classical disease of red-faced old men...

In terms of MRCP, you need to expand the above knowledge to include the following...


Gout usually presents as a single, swollen, hot, painful joint.  If the joint affected is the big toe, it is called a podagra.


Microscopy of joint fluid would reveal negatively birefrigent needle-shaped monosodium urate crystals.

Uric acid may be >450micromols - but equally may be normal in an acute attack.

CRP is usually raised, but if the question shows a raised WCC too start thinking about different diagnoses, for example septic arthritis.



Gout may be either primary or secondary.

Primary gout may be:

• idiopathic - usually due to decreased excretion of uric acid 
• associated with Lesch-Nyhan Syndrome (to be covered in a very brief battle tomorrow)

Secondary gout can broadly be divided into things which cause increased production/intake of urate, and things which decrease its excretion.


Causes of increased production/intake include:

• myeloproliferative/lymphoproliferative disorders
• psoriasis
• cytotoxic drugs
• food - beer, yeast, seafood, liver, kidney
• exercise
• fits
• acidosis

Causes of decreased excretion include:

• renal failure
• diuretics
• low dose aspirin
• alcohol
• lead poisoning

XR should show a normal joint space (may be decreased in late disease) and large punched-out erosions distant from the joint margins.


Treatment is NSAIDs - if these are contraindicated, colchine can be used.


Prophylaxis is with allopurinol (a xanthine oxidase inhibitor).  It should be started 2 to 3 weeks after an acute attack if:

• >1 attack
• tophi present
• renal disease
• urate stones
• Lesch-Nyhan syndrome
• cytotoxic drugs used (in which case it should be given before any episodes of gout)

So after that quick whizz through gout, lets embrace is near-cousin pseudo-gout...

MRCP revision battle 9.3: Pseudogout

Pseudogout involves the deposition of positively birefrigent calcium pyrophosphate dihydrate crystals in joints.


Pseudogout is associated with a variety of conditions, including:

• hyperparathyroidism
• hypothyroidism
• haemochromatosis
• Wilsons disease
• acromegaly
• old age
• OA

It tends to cause a monoarthritis of a larger joint, classically a knee.


An XR may show chondrocalcinosis = soft tissue calcium deposition.


Treatment is with NSAIDs.  If this is unsuccessful steroids or hydroxychloriquine can be considered.



Now on to revision battle 9.4, a treat left over from yesterday, craniopharyngioma...

MRCP revision battle 9.4: Craniopharyngioma

Craniopharyngiomas are benign tumours that arise from the remnants of Rathke's pouch (= area between pituitary and 3rd ventricle floor).

Technically it is not a pituitary tumour as it is derived from the embryonic remnants of the pituitary gland rather than the gland itself.   However, in terms of the mass effects/how it presents it is very similar.  Amenorrhoea and decreased libido are often sited as symptoms.


Craniopharyngiomas frequently calcify (50%)


Investigation of choice is MRI, treatment is surgery.


After that brief squirmish its on to the last battle of the day, the pneumothorax

MRCP revision battle 9.5: Pneumothorax

A pneumothorax, as I'm sure you all know, is a collection of gas in the pleural cavity of the chest between the lung and chest wall.


I'm not about to insult you by going through the basic signs/symptoms of pneumothorax, but I will just briefly mention a rare sign that occasionally pops up in MRCP exams: a clicking sound at the sternal edge synchronised with the heart beat.  This rare sign of a pneumothorax is most commonly assocaited with small left sided pneumothoraces.



As a quick recap, its important to establish if the pneumothorax is primary (ie no underlying lung disease), secondary (=underlying lung disease) or traumatic (in which case as a medic you shouldn't be treating it!)


BTS guidelines state that in primary pneumothorax, if the patient is not breathless and the rim of air is <2cm you do not need to necessarily do anything and may consider sending the patient home.  If the rim of air is >2cm or the patient is breathless you should aspirate; try x2, if still unsuccessful insert a drain.


The guidelines for secondary pneumothorax are slightly more complex:

• if >50yrs old AND breathless AND rim of air >2cm, insert a drain first line
• if the above 3 criteria do not apply, try aspirating first
• regardless of which category your patient falls into, patients with secondary pneumothorax should be admitted for 24 hours observation.

A random type of pneumothorax to be aware of is catamenial pneumothorax - this is a pneumothorax associated with menstruation, which is due to endometriosis of the lung.  90% of these occur on the right side.


As a complete aside, as well as recognising the 'click synchronised with heartbeat' as a possible pneumothorax it is worth learning that a 'crunching sound' in the chest can be due to a pneumomediastinum  and is called Hamman's sign.


Well those are todays battles over, but for those with residual enthusiasm the beat goes on with a war to test your memory of yesterday's topics...

MRCP questions: War 8

As with previous 'wars' after 'battles' these are just a few quick questions to see if your brain cells have retained the information provided in battles 8.1 to 8.6.

Grab a piece of paper, jot down your answers then compare them to my answers here


Question 1:
What is the treatment for cluster headache?


Question 2:
List 3 symptoms of cluster headache.

Question 3:
What odour is associated with acute arsenic poisoning?

Question 4:
List 3 causes of Mees lines

Question 5:
State the 4 H's and 4 T's which are known as the reversible causes of cardiac arrest.


Question 6: 
What kind of visual disturbance is classically associated with a pituitary tumour

Question 7:
What histological type of pituitary tumour is most likely to cause a pressure effect?

Question 8:
What is Nelson's syndrome?


Question 9:
What are the similarities and differences between Romano Ward and Jervell Lange Nielson syndromes?

Question 10:
What is the commonest hormone produced by a pituitary tumour?



answers here

MRCP revision battle 8.1: Cluster headache

Its Saturday and sunny so I'm not particularly feeling the MRCP revision love.  But the battle must continue, and today's topics are:

Revision battle 8.1: Cluster headache
Revision battle 8.2: Arsenic poisoning
Revision battle 8.3: Mee's lines
Revision battle 8.4: Reversible causes of cardiac arrest
Revision battle 8.5 Pituitary tumours
Revision battle 8.6: Romano-Ward and Jervell-Lange-Nielson



Revision battle 8.1: Cluster headache


Cluster headaches appear in the MRCP exam (and occasionally real life) as:

• severe unilateral pain focused around one eye with
• redness of the eye and possibly
• lid swelling with
• lacrimation and
• nasal congestion

It is worth noting that up to 20% will also get ptosis, which in a minority of cases can be permanent.


Cluster headaches are more common in males (5:1).
Risk of suffering from cluster headache is increased if you are a smoker.


Classically patients will suffer from severe 15 minute to 2 hour bouts of pain once or twice a day over a period of 4 to 12 weeks.


Treatment acutely is 100% oxygen.  S/C sumitriptan and nasal lidocaine are also proposed as treatments.

Prophylactic options include verapamil, prednisolone or lithium.


So onwards to a slightly curveball topic - arsenic poisoning...

MRCP revision battle 8.2: Arsenic poisoning

Arsenic poisoning used to be both a favourite method of murder (allegedly involved in the demise of Napoleon) and a substance commonly found in paint and water pipes.  It is now thankfully carefully controlled so it tends to be found mainly in MRCP exam questions...


Arsenic is still used in the glass, smelter and microelectronic industries, and is found in wood preservatives.


Acute poisoning tends to cause features in 30 mins to 2 hours.

Features of acute arsenic poisoning include:

• severe gastroenteritis
• garlic ordour
• hypersalivation

Treatment for acute poisoning is DMPS.


Symptoms of chronic arsenic poisoning present at different times post-exposure; for example, skin symptoms tend to show clinically around 10 years afterwards.  There are multiple, multiple possible complications of chronic arsenic poisoning but a few which may pop up are:

• keratoses
• Mees lines (if you don't know what these are you'll find out in the next battle!)
• hyperpigmentation
• neuropathy
• muscle fasciculation and wasting

So on to explore Mees lines...

MRCP revision battle 8.3: Mees lines

Mees lines are white transverse lines that go all the way across the nail.

An image of Mees lines can be found here


Mees lines are found in:

• arsenic poisoning
• thalium poisoning
• heavy metal poisoning
• renal failure

 Next up: battle 8.4!

MRCP revision battle 8.4: Reversible causes of cardiac arrest

A little bit of a random one to throw into MRCP revision but a quick recap of the reversible causes of cardiac arrest, famously recalled as the 4 Hs and 4 Ts, can never go amiss...


4 H's:

• hypoxia
• hypovolaemia
• hypothermia
• hypoglycaemia/hyper/hypokalaemia/ other electrolyte imbalance

4 T's:

• Tension pneumothorax
• cardiac Tamponade
• Thombus
• Toxins

I remember the 4 H's in the format of a little picture of a man standing on top of a snow-covered mountain.  He is struggling to breath as there's not much oxygen up there (hypoxia) and  is shivering as its so cold (hypothermia).  He is looking sad and in one hand is an empty water bottle (hypovolaemia) and in the other an empty lunchbox (hypoglycaemia... then remember the hypo/hyper kalaemia from that).

For the 4 T's I think of the less happy phrase of 'Thomas has Ten Toxic Tampons' (= Thombus, tension pneumothorax, toxins, tamponade)



So after a couple of nice straightforward battles let face a juicier one: pituitary tumours...

MRCP revision battle 8.5: Pituitary tumours

Most pituitary tumours are benign adenomas.


Symptoms from pituitary tumours are either due to:

• local pressure
• hormone secretion
• hypopituitism

Local pressure symptoms include:

• bitemporal hemianopia (pressure on CN III)
• palsies of CN III/IV/VI (remember the cavernous sinus anatomy at the end of battle 1.1?)

The commonest hormone secreted by pituitary tumours is prolactin (35%) followed by GH (20%).

30% of pituitary tumours secrete no obvious hormone


Potentially a pituitary tumour can disturb hypothalamic control of temperature, sleep or appetite.

If the tumour erodes the floor of the sella the patient may get CSF rhinorrhoea


Histologically, pituitary tumours fall into the following catagories:

• 70% - chromophobes
• 30% cause a pressure effect
• can produce prolactin, ACTH, GH
• 15% - acidophils
• 10% cause a pressure effect
• can produce GH, prolactin
• 15%  - basophils
• rarely cause a pressure effect
• can produce ACTH

The investigation of choice for suspected pituitary tumours  is MRI.


Finally, in this section we need to cover Nelsons Syndrome.  Nelsons syndrome is a condition that occurs after adrenalectomy for pituitary-dependent cushings.  The adrenalectomy removes the negative feedback on the pituitary which causes ACTH levels to rise massively, leading to hyperpigmentation +/- an invasive pituitary tumour.


Tomorrow we will look at craniopharyngioma, but to finish today on a lighter note onwards to Romano Ward and Jervell-Lange-Nielson Syndromes.

MRCP questions: War 7

As with previous 'wars' after 'battles' these are just a few quick questions to see if your brain cells have retained the information provided in battles 7.1 to 7.5.

Grab a piece of paper, jot down your answers then compare them to my answers here

Question 1:
An efflux of which ion terminates the cardiac action potential?

Question 2:
What is the mechanism of action of class III antiarrhythmics?


Question 3: 
Name 2 class IV antiarrhythmic drugs

Question 4:
What is the relationship between heart rate and QT?

Question 5:
How do you calculate QT using the Bazzett formula?

Question 6:
State the upper limit of a normal QT

Question 7: 
Name 5 drugs that prolong QT

Question 8:
State 5 metabolic conditions that can prolong QT

Question 9:
Name 2 drugs that increase the effect of adenosine and one that decreases it.

Question 10:
Does positive concordance in the chest leads make a broad complex tachycardia more or less likely to be VT?


answers here

MRCP revision battle 8.6: Romano Ward and Jervell-Lange-Nielson Syndomes

Both Romano-Ward and Jervell-Lange-Nielson Syndrome are congenitial causes of a long QT.

Both are believed to be caused by mutations in the potassium subunit.

The differences are:

1. Romano-Ward is autosomal dominant while Jervell-Lange-Nielson is autosomal recessive
2. Jervell-Lange-Nielson is associated with bilateral deafness; Romano Ward is not.

Thats all for today; if you want to test your recall of topics covered yesterday click here

MRCP revision battle 7.1: cardiac action potentials

I've got that Friday feeling so I've decided to indulge in a cardiology fest.  Today's revision battles will therefore be:

MRCP revision battle 7.1: cardiac action potentials
MRCP revision battle 7.2: the Vaugham-Williams classification system
MRCP revision battle 7.3: long QT
MRCP revision battle 7.4: adenosine
MRCP revision battle 7.5: cause of the broad complex tachycardia

Now I know that may look like a lot but quite a few of the battles are short and almost sweet, so lets get stuck in!




MRCP revision battle 7.1: cardiac action potentials


Understanding the basics of the cardiac action potential is essential to grasp how antiarrhythmic drugs work.  The basic cardiac action potential looks like this:

                                                                                                            thanks to http://commons.wikimedia.org for the image

In stage 0, there is a rapid influx of sodium
Stage 1 is then an efflux of potassium, followed by
Stage 2, which is an influx of calcium.  Finally in
Stage 3 the efflux of pottasium continues, terminating the action potential.


Try and keep this image in mind as we move on to the fabulous world of Vaughan-Williams classification...

MRCP revision battle 7.2: The Vaughan Williams Classification

The Vaughan-Williams classification is a way of dividing anti-arrhythmic drugs into groups based on their mechanism of action.  It was devised in the 1970s, and like some other inventions of that era (such as flares) it has a few flaws.  The main flaw is that many anti-arrhythmics actually work in several different ways, so although they can be put into a class based on their main mechanism of action this grouping only tells you part of how they work.

However, understanding it a) makes you seem clever (most consultants would have forgotten it within hours of passing MRCP) and b) helps you answer MRCP questions correctly.  So lets ignore its faults and embrace it whole-heartedly...



The original classification had groups I, II, III and IV.  A 'catch all' group of V has now been added for awkward drugs who just didn't fit in anywhere originally.  Lets look at each class in turn:


Class Ia:

• works by blocking sodium channels - called a 'membrane stabiliser'
• distinguishes itself from the other class Is by having intermediate association/dissociation with the sodium channels --> end result longer action potential
• members include disopyramide, quinidine and procainamide

Class Ib:

• works by blocking sodium channels - called a 'membrane stabiliser'
• distinguishes itself from the other class Is by having fast association/dissociation with the sodium channels --> end result shorter action potential
• members include lidocaine and phenytoin

Class Ic:

• works by blocking sodium channels - called a 'membrane stabiliser'
• distinguises itself from the other class Is by having slow association/dissociation with the sodium channels --> end result same action potential
• members include flecanide and propafenone

Class II:

• are beta blockers 
• I'm sure you don't really need examples but think atenolol, bisoprolol, misoprolol...

Class III:

• works by blocking potassium channels
• this results in prolonged repolarisation
• members include amiodarone and sotolol

Class IV:

• works by blocking calcium channels
• members include verapamil and diltiazem

(Class V: = last minute 'catch all', includes digoxin and adenosine)



Thats rather a lot to try and remember; understanding and linking it to the cardiac action potential makes it a bit easier to understand, then a bit of word-play might clarify things further:


To remember the broad classes of drugs, try recalling 'Sodium Blocks Potassium Channels' (just substitute calcium for channels and you have the 4 mechanisms of action)

To remember the members of each class, think "Double quarter pounder, lemonade please, fries please... and salt uh oh vomiting and diarrhoea..."



Got it?  Good, cos you'll need in for battle 7.3, long QT.

MRCP revision battle 7.3: long QT

The QT interval is that sneaky part of the ECG measured from the start of the QRS complex to the end of the T way.  I call it sneaky as as clinicians we rarely pay it much attention, then it just happens to get a bit on the long side and oh whoopsie we have a ventricular arrhythmia on our hands.


The first thing to learn about the QT interval is that it decreases as heart rate increases.  It is therefore necessary to correct it, which is achieved by using either Bazetts or Fridericas formula.

Bazetts = corrected QT = QT/square root of heart rate
Fridericas = corrected QT = QT/cube root of heart rate

Upper limit of normal is generally taken to be 450ms in a man and 470ms in a woman (for some bizarre reason I remember 450 by singing the song 'brimful of asha on the 45' then just remember that females are 20 more)


There are multiple causes of long QT:

1. familial
• Romano-Ward Syndrome (to be covered tomorrow)
• Jervell-Lange-Nielson Syndrome (also to be covered tomorrow)
2. metabolic
• low Mg/Ca/K
• low temp
• low thyroid (also known as hypothyroidism.. :) )
3. drugs
• class I and III antiarrhythmics (which after the last revision battle you should be able to name)
• erythromycin
• TCA/haloperidol/risperidone/SSRIs
• cocaine
• organophosphates
• antihistamines
4. other
• MI
• myocarditis
• SAH

Treatment is possibly beta blockers, possibly ICD.


Now on to revision battle 7.4, to meet a drug that fell into class V...

MRCP revision battle 7.4: Adenosine

Adenosine is a purine nucleoside which clinically is used to try and terminate SVTs/expose the underlying rhythm.  While doing so it has the potential to cause cardiac standstill, so it can have a unique dual action of increasing the adminstering doctor's heart rate in proportion to how much it decreases the receiving patients heart rate.

It's half life is 8 to 15 seconds, and it works by activating potassium channels which decreases AVN conduction.


The effect of adenosine is increased by dipridamol and carbamezepine.
The effect of adenosine is decreased by aminophylline.


A positive of adenosine is that it has no significant negatively inotropic effects.


Risks associated with its use include:

• enhancing conduction through the accessory pathway in Wolff-Parkinson-White
• causing a dangerously fast ventricular response in pre-excited AF/flutter

The side effects include:

• anxiety
• chest tightness
• bronchospasm (avoid in asthma)
• facial flushing
• nausea

The usual dosing regime is 6mg, then if unsuccessful 12mg 2 mins later and if still unsuccessful another 12mg 2 mins after that.  Ensure cardiac monitoring is in place when it is given (it can cause cardiac standstill) and remember that given its short halflife it must be given as a rapid bolus, flushed instantly with saline.



So to the final revision battle of the day, with that most feared ECG pattern: the broad complex tachycardia.

MRCP revision battle 7.5: broad complex tachycardia

At some point an ECG will be shoved under your nose which shows an unnerving broad complex pattern going at a fast rate.  If in doubt, these must always be regarded as VT.  However, there are a few less scary possibilities, such as:

• AF with LBBB
• orthodromic tachycardic WPW
• ventricular paced rhythm

Essentially the main call is whether the broad complex tachycardia is superventricular or ventricular in origin, and the features the MRCP exam expects you to pick up on to differentiate these two are:

• AV dissociation - suggests VT
• fusion/capture beats - suggest VT
• positive QRS concordance in chest leads - suggests VT
• marked left axis deviation - suggests VT
• history of IHD - more likely VT
• QRS>140ms - suggests VT
• no response to adenosine/massage - suggests VT

Well thats if for today.  A quick test of yesterdays topics is available here if you still have the energy.

MRCP questions: War 6

As with previous 'wars' after 'battles' these are just a few quick questions to see if your brain cells have retained the information provided in battles 6.1 to 6.5.

Jot your answers down on a piece of paper then compare them to the answers here

Question 1:
Which HLA is ankylosing spondylitis associated with?

Question 2:
List 5 symptoms/signs associated with acute iritis

Question 3:
What is the correct term for sterile pus in the anterior chamber of the eye?

Question 4:
List 7 infections associated with reactive arthritis


Question 5:
Name and describe a dermatological condition associated with reactive arthritis

Question 6:
What is reiters syndrome?

Question 7:
Define Light's criteria

Question 8:
List 5 possible causes of transudates and 5 possible causes of exudates

Question 9:
Which 5 causes of pleural effusion would cause a low pH (<7.3)?

Question 10:
List 3 associations of yellow nail syndrome




answers here