MRCP revision battle 17.1: DIC

Lots of short battles from a variety of specialities today so buckle up for a ride through some haematology, neurology, endocrinology, respiratory and dermatology.  Yeee-hhaaaa!

MRCP revision battle 17.1: DIC
MRCP revision battle 17.2: Jugular foramen syndrome
MRCP revision battle 17.3: Thyroid cancer
MRCP revision battle 17.4: Legionella infection
MRCP revision battle 17.5: Pleural calcification
MRCP revision battle 17.6: Pseudoxathoma elasticum






MRCP revision battle 17.1: DIC


Disseminated intravascular coagulation (=DIC) is the pathalogical widespread activation of coagulation.


Blood tests will show:

• prolonged PT
• prolonged aPTT
• massively raised d-dimer levels
• low platelets
• low fibrinogen
• schistocytes

Of these, it is the level of fibrinogen which best correlates to the severity.


Causes of DIC include:

• obstetric
• crush injury
• septicaemia
• malignancy
• transfusion reaction

The treatment is:

• treat the cause
• give platelets if platelets <50
• cryoprecipitate
• FFP
• activated protein C if septic.

Now lets canter onwards to jugular foramen syndrome....

MRCP revision battle 17.2: Jugular foramen syndrome

Jugular foramen syndrome, also known as Vermet's Syndrome, is a condition arising from the compression of the cranial nerves that run through the jugular foramen.


Now just in case they aren't quite on the tip of your tongue, the nerves that run through the jugular foramen are IX, X and XI.


The syndrome is therefore characterised by:

• loss of taste to posterior 1/3 of tongue (CN IX)
• dysphagia (CN X)
• sternocleidomastoid and trapezius paralysis (CN XI)

Anything that compresses the jugular foramen can cause this syndrome.  The commonest cause is a paraganglioma.



Now we've acquired a bit more esoteric MRCP knowledge, lets gallop on to discover some details about thyroid cancer...

MRCP revision battle 17.3: Thyroid cancer

Under 5% of thyroid lumps are malignant, and in general those with a malignant mass will be euthyroid.


There are 4 main types of thyroid cancer:

1. papillary - 70% - mainly affects young females, excellent prognosis
2. follicular - 20% 
3. medullary - 5% - associated with MEN-2 (more on MEN tomorrow)
4. anaplastic - 1% - very poor prognosis and resistant to treatment.

Rarely a patient can have lymphoma of the thyroid - this usually follows hashimotos disease.


The mainstay of treatment for thyroid cancer is surgery.



Lets break into a canter as we head on to legionella...

MRCP revision battle 17.4: Legionella

Legionella is a gram negative bacteria which causes legionella disease/pneumonia and in MRCP questions is most likely found living in a cruise ship/hotel's water tank or airconditioning system.



The symptoms of legionella disease are:

• flu-like
• dry cough
• dypnoea
• GI upset

Complications of legionella which may show up in the blood results include:

• SIADH - low sodium
• hepatitis - deranged LFTs

Legionella is killed above 60c, cannot multiply between 50 and 60c and are happiest between roughly 35 to 45 c


Males are more affected than females, 3:1


CXR may show bibasal consolidation.


Treatment is with antibiotics which achieve a high intracellular concentration, such as clarithromycin, rifampicin or fluroquinolone.


Legionella has a 10% mortality.



Lets now trot on to pleural calcification...

MRCP revision battle 17.5: Pleural calcification

Pleural calcification pops up both in real life and in MRCP questions intermittently.


The commonest cause is asbestosis. 
This tends to be bilateral and spare the costophrenic angles


So, if the pleural calcification is unilateral consider:

• previous haemothorax
• previous TB pleuritis
• previous empyema

Other differentials to consider are:

• previous radiotherapy/radiation exposure
• post talc pleurodesis, which will mimic calcification.

Lets return to a full-speed gallop to our last battle of the day, pseudoxanthoma elasticum

MRCP revision battle 17.6: Pseudoxanthoma elasticum

Pseudoxanthoma elasticum is fragmentation and calcification of elastic fibres.


It is an autosomal recessive condition, found on chromosome 16.


Its various associations are:

• a characteristic 'plucked chicken' skin (google it, memorise it, get ready to spot it in part 2)
• angioid streaks in retina/vision problems
• rarely GI bleeds
• claudication/cardiovascular problems.

There is no treatment so management is symptomatic only.


Thats all for today, proceed to the war if you are up to.

MRCP questions: War 16

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 16.1 to 16.7.

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


Question 1:
List 8 symptoms/signs of pagets disease


Question 2:
Which oral medication would you give to treat pagets disease?


Question 3:
Which medication would you use to treat PCP?


Question 4:
A patient has muscle weakness that gets worse on exercise.  What medication would you give them?


Question 5:
A patient tells you they have weak muscles which get better on exercising.  They state they believe its due to their lung cancer.  What condition do they have?


Question 6:
]What is the commonest cause of hemiballismus?



Question 7:
What is the medical treatment for hyperprolactinoma?


Question 8:
'Waiters tip' is associated with which palsy?




The answers are here

MRCP revision battle 16.1: Pagets disease of bone

In between catching up on seemingly endless loads of washing (do socks breed when left alone in a wash basket?) a few hours of MRCP revision has been done and 7 new battles have been written...

MRCP revision battle 16.1: Pagets disease of bone
MRCP revision battle 16.2: Pneumocystis carinii
MRCP revision battle 16.3: Myasthenia gravis
MRCP revision battle 16.4: Lambert-Eaton syndrome
MRCP revision battle 16.5: Hemiballismus
MRCP revision battle 16.6: Prolactin
MRCP revision battle 16.7: Erbs palsy





MRCP revision battle 16.1: Pagets disease of bone


Pagets disease of bone is accelerated, disorganised bone turnover due to increased number and activity of osteoclasts and osteoblasts.


It is rare in under 40s.


Predisposing factors include:

• increasing age
• northern latitude
• family history
• being male

Features of Pagets include:

• bone pain
• bowing of tibia
• bossing of skull
• secondary arthritis
• deafness/other cranial nerve compression
• high output heart failure
• pathological fractures
• bone sarcomas (occur in 1% over 10 yrs)

My way of remembering the features of pagets is this slightly random rhyming story:
"Bowing to the Boss, oh what a pain,
I'm deaf and arthritic and since the fracture I'm lame
my heart's now a failure, and oh what a shame
I've got bone sarcoma - thats the end of the game"



Bloods in Pagets show:

• raised ALP
• normal calcium (unless a long period of immobility)
• normal phosphate

Treatment is alendronic acid



That wasn't too bad... onwards to battle 16.2...

MRCP revision battle 16.2: Pneumocystis carinii

Pneumocystis carinii, AKA pneumocystis jiroveci, is a unicellular eukaryote.

It can cause pneumonia in patients with HIV and accounts for 40% of all AIDS-defining illness.
If CD 4 count is less than 200 PCP prophylaxis (=co-trimexazole) should be started.



Features of PCP:

•  dyspnoea
• dry cough
• fever
• few chest signs on examination
• desaturation on exercise

CXR typically shows mid-lower bilateral interstitial infiltrates, but it may look normal.

Sputum cultures are often negative so BAL may be needed.



Treatment is:

• co-trimexazole
• IV pentamidine if severe
• steroids if hypoxia
• use of steroids decreases respiratory failure by 50% and death by 1/3)

On to battle 3 of the day and a classic condition - myasthenia gravis.

MRCP revision battle 16.3: Myasthenia Gravis

Myasthenia gravis is an autoimmune condition in which muscles become easily tired and weak.  It affects 1 in 20 000.


90% of patients have autoantibodies to nicotinic acetylcholine receptors.
If these are negative consider looking for MUSK antibodies (= muscle specific kinase)


The key feature of MG is repetitive stimulation leading to decreased evoked response.


The order in which muscle groups are affected in MG is:

• extraoccular (--> diplopia)
• bulbar
• face
• neck
• lumb
• trunk

Reflexes are normal in MG.


Test of choice: tensilon test = edrophonium


Treatment of MG is:

• cholinesterase inhibitors eg pyridostigmine
• prednisolone if pyridostigmine unsuccessful (but be aware that paradoxically steroids can worsen MG)
• plasmaphoresis/IV IG if respiratory muscle involvement.

If there is hyperplasia of thymus/thyroma, up to 60% of cases will remit after surgery.


Up to 10% of patients with MG will have hyperthyroidism.


Drugs which exacerbate MG include:

• penicillamine
• quinidine
• beta blockers
• lithium
• phenytoin
• gentamycin

Now on to the 'similar but different' Lambert-Eaton syndrome...

MRCP revision battle 16.4: Lambert Eaton Syndrome

Lambert-Eaton syndrome is a rare condition affecting voltage-gated calcium channels which results in:

• muscular weakness that improves with activity
• autonomic symptoms (dry mouth, constipation, impotence)
• hyporeflexia

 

It is most commonly a paraneoplastic phenomenon, usually due to small cell lung cancer (very rarely due to breast or ovarian cancer).  It can also be autoimmune.


Treatment is 3,4 diaminopyridine.

Regular CXR should be performed as Lambert-Eaton may preceed the development of small cell lung cancer by up to 4 years.



Notice how although both MG and Lambert-Eaton are characterised by muscle weakness there are lots of differences - weakness gets worse on repetition in MG but better in LE, reflexes are normal in MG but reduced in LE and there may be autonomic symptoms in LE but not MG.  Also not involvement of occular muscles is far more common in MG.



Lets now diversify to something completely different - hemiballismus...

MRCP revision battle 16.5: Hemiballismus

Hemiballismus is large amplitude, flinging hemichorea.


Its cause is damage to the contralateral subthalamic nuclei.


The commonest cause is stroke.


Treatment:

• hemiballismus generally resolves spontaneously in 4 to 8 weeks
• haloperidol (a dopamine blocker) may be used
• tetrabenazine (a VMAT inhibitor) may be used

Bilateral hemiballismus is rare and tends to be associated with HONK.



After that brief battle onwards to the meatier topic of prolactin

MRCP revision battle 16.6: Prolactin

Prolactin is a hormone released from the anterior pituitary.
It is under the negative control of dopamine (ie dopamine prevents its release)


Raised prolactin causes a drop in GnRH, LH, oestrogen and testosterone levels.


Symptoms/signs of raised prolactin include:

• galactorrhoea
• decreased libido
• amenorrhoea
• infertility

Note that gynaecomastia is NOT associated with raised prolactin.


Causes of a raised prolactin include:

• physiological causes
• pregnancy
• breast feeding/nipple stimulation
• stress
• post-fit
• exercise
• drugs
• phenothiazides
• metoclopramide
• methyl-dopa
• haloperidol
• oestrogens
• metabolic causes
• hypothyroidism
• PCOS
• acromegaly (1/3)
• chronic renal failure
• disease
• prolactinoma
• microprolactinoma (<10mm) release more prolactin than macroprolactinomas
• compression of pituitary stalk removing dopamine control

Treatment is with bromocriptine.
It is best to give it in the evening as it causes postural hypotension



Very nearly there.  Last battle of the day will be Erbs palsy....

MRCP revision battle 16.7: Erbs palsy

Erbs palsy is the name given to a particular brachial plexus injury, generally caused by shoulder dystocia during birth.


Any nerve root of the brachial plexus may be affected but the most commonly affected roots are C5 and C6.


This results in loss of:

• shoulder abduction
• elbow flexion
• suppination

The net outcome is that the arm hangs medially rotated with the forearm pronated = "waiters tip"


So thats all for today's battles - on to today's war to check recall of yesterday's battles!

MRCP questions: War 15

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 15.1 to 15.8.

The answers are available here


Question 1:
List the 3 commonest sites of mets from renal cell carcinomas


Question 2:
What abnormalities on blood tests might you see with renal cell carcinoma?


Question 3:
What is Von Hippel Lindau disease?



Question 4:
A patient complains of severe right shoulder pain followed by weakness of the right arm.  There is no history of trauma.  What is the likely diagnosis?

Question 5:
A patient has abdo pain.  The busy nurse just leaves their urine sample in front of you.  Ten minutes later you notice it has turned deep red.  What condition does the patient have?


Question 6:
List 3 drugs that can precipitate acute porphyria

Question 7:
A medical student excitedly tells you the urine sample they've just taken glows pink under woods light.  What condition does the patient have?


Question 8:
Your newest patient has heart block, opthalmoplegia and pigmentary degeneration of the retina.  What test do you want to do to confirm your diagnosis?


Question 9:
List 7 symptoms associated with pellegra

Question 10:
Which drug is used to treat neuroleptic malignant syndrome?

MRCP revision battle 15.1: Renal cell carcinoma

I've had a day off in which I've covered literally hundreds of miles and drank excessive amounts of tea and cider and seen far more gingham than any one person ever should.  Net result has been a restoration in my energy levels and so today is going to be a blockbuster of a set of battles, with 8 separate topics to cover including two that I'd never even heard of in my preceding 8 years of studying medicine.  So lets get started!


MRCP revision battle 15.1: Renal cell carcinoma
MRCP revision battle 15.2: Von Hippel Lindau
MRCP revision battle 15.3: Neuralgic amyotrophy
MRCP revision battle 15.4: Porphyrias
MRCP revision battle 15.5: Kearns-Sayre
MRCP revision battle 15.6: Klinefelters
MRCP revision battle 15.7: Pellegra
MRCP revision battle 15.8: Neuroleptic malignant syndrome






MRCP revision battle 15.1: Renal cell carcinoma


Renal cell carcinoma, also known as hypernephroma or Gravitz Tumour, is a cancer arising in the proximal renal tubular epithelium.

It accounts for 85-90% of primary renal cancer.


The classic triad for renal cell carcinoma is:

1. haematuria
2. loin pain
3. abdominal mass

(NB: classic triads of course rarely exist, but may kindly present themselves during MRCP questions)


Renal cell carcinoma may also be linked to pyrexias of unknown origin.
Another clinical sign to look out for is left variocele - caused by invasion of the left renal vein causing compression of the left testicular vein.



Factors associated with developing renal cell carcinoma include:

• smoking
• middle aged males (male:female 2:1)
• Von-Hippel Lindau syndrome (wait for the next battle if you don't know that that is)
• tuberous sclerosis
• acquired cystic kidney disease in renal failure

25% of patients with renal cell carcinoma have mets at presentation.  The commonest mets are bone, liver and lung.


Endo effects associated with renal cell carcinoma include:

• erythropoietin --> polycythaemia
• PTH --> raised calcium
• renin --> raised BP
• ACTH

Treatment is surgery.  If mets are present IL-2 or interferon alpha may also be considered.


There is a 45% 5 yr survival.


Now on to meet Von-Hippel-Lindau syndrome...

MRCP revision battle 15.2: Von Hippel Lindau disease

Von Hippel Lindau disease is a rare autosomal dominal condition that results in haemangioblastomas in:

• cerebellum (may present as ataxia)
• spinal cord
• kidney
• retina (may present as visual loss)

It is associated with bilateral renal cell carcinomas (develop in approximately 50% of patients with VHL) and pheochromocytomas.


For those of you who are feeling really geeky the gene responsible is on chromosome 3 and it is a mutation in a tumour supressor gene.



So after that brief acquaintance, lets move on to a condition I'd never heard of before today - neuralgic amyotrophy...

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..