Clinical SBAs
Clinical Neurology: (32 questions)

Questions

• 1
  A 47-year old man presents with sudden onset hemiparesis and homonymous hemianopia. CT excludes haemorrhage. What is the optimum antiplatelet therapy for this man?
  Difficulty: Medium     Topic: Sudden hemiparesis and hemianopia
  a

  Aspirin alone

  b

  Clopidogrel alone

  c

  Aspirin and dipyridamole

  d

  Aspirin and clopidogrel

  e

  Clopidogrel and dipyridamole
  Explanation: This man has suffered an ischaemic stroke affecting the anterior territory. For antiplatelet therapy in NICE recommends aspirin plus dipyridamole (a thromboxane synthase inhibitor). Aspirin plus clopidogrel is used as antiplatelet therapy for ischaemic cardiac events. If aspirin causes dyspepsia then a PPI should be added. If intolerant of aspirin due to hypersensitivity (e.g. asthma) then clopidogrel (an ADP-receptor antagonist) should be used instead.
• 2
  A 41-year old woman presents with feeling tired all the time. She is noted to have bilateral partial ptosis that is fatigueable. Tensilon test is positive. What is the most appropriate treatment?
  Difficulty: Medium     Topic: Fatigue and ptosis
  a

  Levothyroxine

  b

  Pyridostigmine and prednisolone

  c

  Oral cobalamin

  d

  Oral methylprednisolone

  e

  Bromocriptine
  Explanation: This woman has myasthenia gravis, an autoimmune condition characterised by weakness due to autoantibodies produced against nicotinic acetylcholine receptors. Treatment is immunosuppressive (with prednisolone) and with an anticholinesterase (pyridostigmine), which increases ACh concentration in the synapse that improves symptoms. Levothyroxine treats hypothyroidism. Oral cobalamin is given for dietary B12 deficiency. Methylprednisolone is treatment for multiple sclerosis. Bromocriptine is used for prolactinomas and Parkinson's'.
• 3
  A partially bald 29-year old man presents with weakness in his hands and legs. He complains of spasms of muscle contraction and being unable to let go when he shakes hands. What is the most likely diagnosis?
  Difficulty: Easy     Topic: Weakness in a bald man
  a

  Fascioscapulohumeral muscular dystrophy

  b

  Dystrophia myotonica

  c

  Lambert-Eaton myasthenic syndrome (LEMS)

  d

  Motor neurone disease (MND)

  e

  Duchenne's muscular dystrophy (DMD)
  Explanation: Myotonic dystrophy has autosomal dominant inheritance and other features are: cataracts, heart block and endocrinopathies. Fascioscapulohumeral dystrophy presents with facial and upper arm weakness in teenage years. LEMS is a paraneoplastic condition from small cell lung cancer, it presents similarly to myasthenia gravis. MND may show these features but is most common >40yrs with a mix of UMN and LMN signs - especially bulbar palsy. DMD is a X-linked condition with weakness presenting before 5yrs.
• 4
  A 52-year old man presents with progressive proximal weakness with LMN signs and a type 2 respiratory failure. His wife say he is normally fit and well apart from gastroenteritis on holiday, and does not take any medications. What is the most appropriate management?
  Difficulty: Medium     Topic: Progressive lower-motor weakness
  a

  MRI head

  b

  IV dexamethasone

  c

  IV cobalamin

  d

  Urgent dialysis

  e

  IV immunoglobulin
  Explanation: This man has Guillain-Barré syndrome: a post-infectious ascending polyneuropathy affecting proximal and respiratory muscles. Gastroenteritis or URTI are frequent precipitants. 1st line treatment is with IV immunoglobulin, then plasma exchange may be tried if this is not effective. MRI head would used for suspected central lesion but this would cause UMN signs. Dexamethasone would be used if a SOL were suspected. Cobalamin would treat B12-deficiency causing subacute degeneration of the cord, which rarely involves respiratory muscles. Dialysis would be used for lead poisoning or uraemia.
• 5
  A 30-year old woman presents with headache that is worst in the morning and when coughing, which is also associated with nausea. MRI shows no abnormalities. What is the most likely diagnosis?
  Difficulty: Easy     Topic: Morning headache
  a

  Neurocysticercosis

  b

  Normal pressure hydrocephalus

  c

  Idiopathic intracranial hypertension

  d

  Glioblastoma multiforme

  e

  Neurosyphilis
  Explanation: IIH is a condition that is most common in obese young-middle aged woman. It may also present with reduced vision/enlarged blind spot from papilloedema. Weight loss is important in the management, drugs include: diuretics, steroids and acetazolamide. Neurocysticercosis is infection with Taenia solium (pork tape worm); lesions would be seen on MRI. Normal pressure hydrocephalus presents with ataxia, incontinence and dementia. A grade 4 astrocytoma (= glioblastoma multiforme) and gummas of neurosyphilis would be visible on MRI.
• 6
  A 31-year old woman presents with reduced vision and pain in her right eye, especially on lateral gaze. 2 years ago she had an episode of reduced sensation in her right leg. Which of the following is not consistent with the diagnosis?
  Difficulty: Hard     Topic: Painful reduced vision
  a

  Lhermitte's sign

  b

  Relative afferent pupillary defect (RAPD)

  c

  Internuclear opthalmoplegia (INO)

  d

  Oligoclonal IgM bands in CSF

  e

  Antibodies to myelin oligodendrocyte glycoprotein
  Explanation: This woman has MS: optic neuritis and previous focal deficit make the diagnosis likely. In MS there are oligoclonal IgG (not IgM) bands in the CSF that are not in the serum. Lhermitte's sign is a shock-like sensation through the body on neck flexion (also in cervical spondylosis). RAPD shows previous optic nerve damage and occur with optic neuritis. INO is a failure of eye adduction with nystagmus in the abducting eye; showing demyelination to the medial longitudinal fasiculus.
• 7
  On examination of a 72-year old man’s neurological system, fasiculations are visible on the left side of the tongue when it is protruded. What is the most likely cause?
  Difficulty: Easy     Topic: Cranial nerve examination
  a

  Normal

  b

  Left glossopharyngeal nerve lesion

  c

  Right glossopharyngeal nerve lesion

  d

  Left hypoglossal nerve lesion

  e

  Right hypoglossal nerve lesion
  Explanation: When examining the tongue for fasiculations it should be resting and inside the mouth. If protruding there can variable fasiculation-like movements that are physiological. Cranial nerve (or nuclei) lesions cause ipsilateral signs. Glossopharyngeal lesions cause: loss of the gag reflex, loss of taste from posterior 1/3 of the tongue and reduced saliva production (from parotid gland). Hypoglossal lesions cause ipsilateral tongue weakness so on protrusion the tongue will deviate towards the side of the lesion.
• 8
  A 73-year old man with severe Parkinson’s disease suffers from ‘on-off’ periods. He is going to be started on an injection for this, what is this new medication most likely to be?
  Difficulty: Hard     Topic: Parkinson's disease medication
  a

  Apomorphine

  b

  Cabergoline

  c

  Carbidopa

  d

  Entacapone

  e

  Ropinirole
  Explanation: Apomorphine is a D1 & D2 agonist that is given by subcutaneous injection and helps with severe on-off periods after long-term L-DOPA treatment. Cabergoline and ropinirole are D3-agonists that are new alternatives to L-DOPA. Carbidopa is a dopa-decarboxylase inhibitor that is given with L-DOPA to help reduce peripheral metabolism. Entacapone is a COMT-inhibitor, which also prevents peripheral metabolism of L-DOPA and helps to reduce 'off' periods.
• 9
  A 56-year old man with atrial fibrillation is started on a new anti-epileptic drug and is warned that it he may have to either increase or decrease his dose of warfarin. Which of the following is most likely to be responsible?
  Difficulty: Medium     Topic: Anti-epileptic drugs 2
  a

  Valproate

  b

  Carbamazepine

  c

  Levetiracetam

  d

  Lamotrigine

  e

  Phenytoin
  Explanation: Phenytoin is an CYP enzyme inducer however its interactions with warfarin can lead to either an increase or a decrease in activity. Whereas carbamazepine is a strong enzyme inducer and leads to a marked decrease in warfarin activity. The other medications listed do to significantly interact with warfarin.
• 10
  A 32-year old woman with epilepsy is started on a new medication and develops diplopia, dysarthria, ataxia and dysmetria. What medication is most likely to be responsible?
  Difficulty: Hard     Topic: Anti-epileptic drugs 1
  a

  Gabapentin

  b

  Lamotrigine

  c

  Levetiracetam

  d

  Phenytoin

  e

  Valproate
  Explanation: This woman has presented with signs of cerebellar toxicity, which have been caused by phenytoin, a frequently used anti-epileptic. In toxicity phenytoin causes: tremor, diplopia and cerebellar signs, other side-effects include depression, gingivitis, acne and depression. Lamotrigine has many side-effects but can cause a severe rash, which is worst if also taking sodium valproate. Other SE: 'flu-like prodrome, raised LFTs and visual effects. The main side-effects of gabapentin are on the GI system. Levetiracetam's side effects are: GI disturbance, double-vision, sedation and low WCC (rarely). The main side-effects of valproate are sedation, tremor, weight gain and alopecia.
• 11
  A 45-year old man presents with severely reduced vision and a history of early morning headaches and vomiting. His right optic disc appears pale and has papilloedema on the left. What is the most likely diagnosis?
  Difficulty: Hard     Topic: Neurological eponyms
  a

  Devic's syndrome

  b

  Foster-Kennedy syndrome

  c

  Gerstmann's syndrome

  d

  Todd's palsy

  e

  Weber's syndrome
  Explanation: Foster-Kennedy syndrome occurs with a unilateral frontal lobe SOL. This compresses the optic nerve causing ipsilateral optic atrophy and mass effects cause contralateral papilloedema. Devic's syndrome is a demyelinating condition that affects the optic nerve and spinal cord. Gerstmann's occurs due to a dominant parietal lobe lesion that causes: left-right confusion, agraphia, alexia and agnosia. Todd's palsy is transient weakness post-seizure that mimics stroke. Weber's occurs from midbrain infarction, causing ipsilateral CN III palsy and contralateral hemiplegia.
• 12
  A 21-year old man is brought to A&E with reduced conscious level after being involved in a fight. CT head shows a biconvex high attenuation area on the right side. What is the most likely diagnosis?
  Difficulty: Easy     Topic: Reduced consciousness after trauma
  a

  Cerebral contusion

  b

  Intracerebral haemorrhage

  c

  Subarachnoid haemorrhage

  d

  Subdural haemorrhage

  e

  Extradural haemorrhage
  Explanation: A history of trauma with reduced conscious level is typical for extradural haemorrhage, which occur due to laceration of the meningeal vessels. The CT findings are due to the bleed being bound by the attachments of the dural to the cranium. Contusion may not cause any CT findings, or loss of grey-white matter interface if severe. Intracerebral and subarachnoid haemorrhages are not usually associated with trauma. Subdural haemorrhages cause a convex bleed that may be isodense due to its chronicity where it has clotted.
• 13
  A 78-year old man with history of alcohol dependency presents with confusion. His wife says he has become more drowsy over the last 4 days. He cannot remember having had any falls recently. He suffers a seizure whilst on the ward. Which of the following diagnoses is most likely?
  Difficulty: Easy     Topic: Alcohol dependency with confusion
  a

  Dementia

  b

  Neurocysticercosis

  c

  Cerebral abscess

  d

  Stroke

  e

  Subdural haemorrhage
  Explanation: Despite no history of a fall, a steadily reducing level of consciousness in an elderly patient is suggestive of a subdural bleed. Patients with dementia or alcohol dependency are at higher risk of subdural haemorrhage. CT shows the concave bleed or midline shift from mass effect. Burr hole drainage is the preferred treatment. Dementia would present much more insidiously than this and is not associated with seizures until very late on in the disease process. 'B' & 'C' would also have a longer history of mass effects (early morning headache & nausea). Stroke is unlikely if there has been a seizure and the vignette doesn't describe any focal neurology.
• 14
  A 33-year old woman presents 2 hours after onset of a severe headache with vomiting and papilloedema but no signs of meningism. She is weak in her left leg and arm. She takes the OCP and lansoprazole. What is the most likely diagnosis?
  Difficulty: Easy     Topic: Headache without meningism
  a

  Sub-arachnoid haemorrhage

  b

  Encephalitis

  c

  Pituitary apoplexy

  d

  Sagittal sinus thrombosis

  e

  Ischaemic stroke
  Explanation: Sagittal sinus thrombosis is more likely in patients with risk factors: OCP, pregnancy, hypercoagulability. It presents in a similar manner to SAH but without meningism. CT shows absence of haemorrhage and there is raised opening pressure on LP. SAH, encephalitis and pituitary apoplexy would all present with meningism and are likely to cause change in conscious less. Pituitary apoplexy may occurs due to haemorrhage inside a pituitary tumour. This causes rapid enlargement of the pituitary with mass effect. Apoplexy and SAH may cause rapid death. Ischaemic strokes rarely cause headache but can cause late papilloedema from oedema surrounding the infarcted area.
• 15
  A 31-year old woman presents with a severe occipital headache and a positive Kernig’s sign. There are bilateral masses felt in the flanks. What is the next most appropriate step in this patient’s care?
  Difficulty: Easy     Topic: Headache and Kernig's sign
  a

  IV benzylpenicillin

  b

  IV cefotaxime

  c

  CT head

  d

  MRI head

  e

  Lumbar puncture
  Explanation: This woman has had a subarachnoid haemorrhage due to a rupture of berry aneurysm, which is associated with polycystic kidney disease. CT head should be done to confirm bleed, then contact neurosurgery and give nimodipine given that they are no hypotensive. IV benzylpenicillin or cefotaxime are antibiotic options for use in bacterial meningitis. MRI head is less sensitive than CT for diagnosing haemorrhage. LP can be done for SAH >12hrs if there is high suspicion but CT is negative, looking for xanthochromia.
• 16
  A 67-year old man presents with a 30minute episode of left-sided facial weakness that completely resolves. He suffered a large anterior MI 10 days ago. Echocardiogram shows a hypoechoic mass in the left ventricle. What is the most appropriate management?
  Difficulty: Medium     Topic: 30minute weakness
  a

  Anti-hyperlipidaemia therapy

  b

  Anti-hypertensive therapy

  c

  Anti-platelet therapy

  d

  Anti-coagulation therapy

  e

  Carotid endarterectomy
  Explanation: This man has had a TIA and further ischaemic events must be prevented. A common complication of large anterior MI are ventricular thrombi, which may throw off clots. It is appropriate to anticoagulate with warfarin and perform an echocardiogram. Following MI this man should already be on 'A-C'. Endarterectomy is only indicated if carotid Doppler demonstrates 75-99% stenosis in those medically fit - the history does not give enough information to decide on this.
• 17
  A 76-year old woman presents with a fall. She has jerky nystagmus on right gaze. Where is the lesion most likely to be?
  Difficulty: Easy     Topic: Right nystagmus
  a

  Right hemi-cerebellum

  b

  Left hemi-cerebellum

  c

  Right internal capsule

  d

  Left hemi-cerebrum

  e

  Right hemi-cerebrum
  Explanation: Nystagmus is a sign of cerebellar damage and this lady's fall may be due to ataxia, diplopia or dizziness also seen in cerebellar stroke. Unlike the cerebrum, the cerebellum has ipsilateral action on the body. Cerebral cortex strokes cause contralateral motor or sensory signs, visual impairment and altered higher function (rarely loss of consciousness). The internal capsule carries the white tracts that project onto each hemi-cerebral cortex; infarction causes gross contralateral deficits.
• 18
  A 61-year old lady with presents with sudden onset ataxia, nystagmus and dysarthria. What is the least appropriate investigation?
  Difficulty: Medium     Topic: Sudden ataxia, dysarthria and nystagmus
  a

  ECG

  b

  FBC

  c

  ESR

  d

  Clotting studies

  e

  Carotid Doppler
  Explanation: This lady has presented with features of a cerebellar stroke, which is supplied by the posterior cerebral artery. Carotid artery disease does not cause embolic stroke in the posterior circulation (brainstem or cerebellum) therefore Doppler assessment is not required. ECG may show AF or ischaemic changes. FBC may show polycythaemia or thrombocythaemia. Raised ESR may occur in GCA or other vasculitis. Clotting should be checked if haemorrhagic stoke is considered.
• 19
  A 58-year old woman with schizophrenia presents with uncontrollable chewing-like movements of her mouth and turning of her neck. Which of the following medications if most likely to be responsible?
  Difficulty: Easy     Topic: Schizophrenic movement disorders
  a

  Risperidone

  b

  Olanzapine

  c

  Quetiapine

  d

  Chlorpromazine

  e

  Aripiprazole
  Explanation: This woman is suffering from tardive dyskinesia, which occurs due to up-regulation of dopamine-receptors following long-term dopamine antagonism, usually from typical neuroleptics. Chlorpromazine is a typical antipsychotic. All the remaining medications are atypical antipsychotics and are much less likely to cause extra-pyramidal side-effects.
• 20
  A 67-year old diabetic lady presents with wild, flailing movements of her left arm that she cannot stop and are not associated with activity or rest. Where is the lesion most likely to be?
  Difficulty: Easy     Topic: Unilateral flailing limb
  a

  Subthalamic nucleus

  b

  Caudate nucleus

  c

  Putamen

  d

  Internal capsule

  e

  Substantia nigra
  Explanation: These movements described are hemi-ballisms, which occur due to lesions of the subthalamic nucleus that normally acts to suppress movement. It is more common in diabetics.
• 21
  A 35-year old man presents with recurrent black-outs. He has no warning and does not remember hitting the floor but feels fine immediately afterwards. A friend tells him that one time he jerked a little and he says he bit his tongue once. What is the most likely diagnosis?
  Difficulty: Easy     Topic: Recurrent syncope
  a

  Temporal lobe epilepsy (TLE)

  b

  Absence seizures

  c

  Stokes-Adams attacks

  d

  Vasovagal syncope

  e

  Postural hypotension
  Explanation: Stokes-Adams attacks cause syncope due to transient arrhythmias associated with reduced cerebral perfusion pressure. Cerebral hypoxia can cause minor jerking and tongue biting without true seizure activity. TLE seizures are usually preceded by an aura. Absence seizures are an isolated reduction in level of consciousness with automatisms. Vasovagal syncope gives nausea, light-headedness and dizziness before blackout. Postural hypotension gives similar symptoms of dizziness and a history of standing up prior to collapse.
• 22
  A 61-year old man is taking a medication for prevention of headaches. He develops a drug reaction causing a retroperitoneal fibrotic mass that causes bilateral ureteric obstruction. What is the most likely cause?
  Difficulty: Hard     Topic: Headache treatments
  a

  Sumatriptan

  b

  Gabapentin

  c

  Methysergide

  d

  Pizotifen

  e

  Valproate
  Explanation: This man has developed retroperitoneal fibrosis (peri-aortitis) due to methysergide, which is used as prophylaxis for cluster headaches. Sumatriptan is used for acute treatment of migraine and can cause arrhythmia/MI (even in those previously well). Gabapentin is 2nd line prophylaxis for migraine, which GI side-effects. Pizotifen is used 1st line for migraine prophylaxis and causes drowsiness and weight gain. Valproate is 2nd line for migraine prophylaxis and can cause tremor, weight gain and alopecia.
• 23
  A 55-year old man presents with recurrent right sided headaches that always occur at 10-11pm and last 1-2hrs and are associated with lacrimation. He describes the pain as severe and 10/10 severity. What is the most likely diagnosis?
  Difficulty: Medium     Topic: Recurrent unilateral headache
  a

  Trigeminal neuralgia

  b

  Medication overuse headache

  c

  Giant cell arteritis

  d

  Migraine

  e

  Cluster headache
  Explanation: Cluster headaches tend to occur daily for weeks, followed by a span without any headaches. They may also cause the eye to become bloodshot, with ptosis and also rhinorrhoea. Acutely, 100% oxygen gives effective analgesia. Trigeminal neuralgia causes seconds of stabbing pain in the distribution of CN V. Medication overuse causes daily headaches with non-specific features. GCA causes jaw claudication, scalp tenderness with unilateral headaches and may lead to blindness
• 24
  A 68-year old woman presents with a severe frontal headache, right eye pain, blurred vision with haloes and nausea. What is the most appropriate management?
  Difficulty: Medium     Topic: Severe frontal headache
  a

  IV labetalol

  b

  CT head

  c

  IV benzylpenicillin

  d

  Opthalmology referral

  e

  100% oxygen
  Explanation: This woman is suffering from acute angle closure glaucoma, which causes rapid increase in intra-ocular pressure and reduced vision. She should be referred to opthalmology for assessment of her intraocular pressures and measurement of the draining angle. If confirmed as AACG IV acetazolamide is the treatment of choice, followed by laser iridotomy. Labetalol is used as treatment for malignant hypertension. CT head should be requested if subarachnoid haemorrhage is suspected. Benzylpenicillin is initial treatment for meningitis in the community, followed by immediate transportation to hospital. 100% oxygen gives relief from cluster headaches.
• 25
  A 67-year old man has a brisk supinator reflex. Where is the spinal cord lesion most likely to be?
  Difficulty: Medium     Topic: Supinator reflex
  a

  C5

  b

  C6

  c

  C7

  d

  C7

  e

  T1
  Explanation: The supinator reflex is innervated by C6. Spinal cord lesions cause LMN signs at the level of the lesion (reduced reflexes) and UMN signs below the level (brisk reflexes). Therefore the lesion must be above C6, and C5 is the only that would cause this sign from those given.
• 26
  A man receives blunt trauma to his temple and is knocked unconscious. He slowly improves but several hours later deteriorates and dies. Which vessel is most likely to have been affected?
  Difficulty: Easy     Topic: Head trauma
  a

  Middle cerebral artery

  b

  Middle meningeal artery

  c

  Anterior cerebral artery

  d

  Anterior meningeal artery

  e

  External carotid artery
  Explanation: This man suffered an extra-dural haemorrhage, the slow recovery and 'lucid interval' is typical before deterioration and death due to raised ICP. Trauma to the side of the head frequently fractures the pterion, which is where the frontal, temporal, parietal and sphenoid meet. Underlying this is the middle meningeal artery, which is often damaged and causes the extra-dural bleed.
• 27
  A 55-year old painter presents with recurrent episodes of dizziness, nausea and difficulty speaking that tend to occur after he has been painting a ceiling with his left arm, or if he carries heavy objects in his left hand. Right arm BP 134/98mmHg, left arm 118/82mmHg. Where is the lesion most likely to be?
  Difficulty: Medium     Topic: Recurrent dizziness and dysarthria
  a

  Basilar artery

  b

  Vertebral artery

  c

  Aortic arch

  d

  Thoracic outlet

  e

  Subclavian artery
  Explanation: This man has subclavian steal syndrome. A stenosis in the proximal subclavian artery results in compensatory retrograde flow down the vertebral artery to help supply the arm when it is being used. This then causes intermittent symptoms of brainstem ischaemia. Aortic dissection can also cause a difference in arm BP.
• 28
  A 70-year old man presents with vomiting and complains of dizziness. There is lateral gaze nystagmus when looking to the right and loss of pain sensation on the right half of the face. The right pupil is meiotic with a partial ptosis. Where is the lesion most likely to be?
  Difficulty: Hard     Topic: Vomiting, dizziness and nystagmus
  a

  Left pons

  b

  Right pons

  c

  Left medulla

  d

  Right medulla

  e

  Central medulla
  Explanation: This man has Wallenberg's lateral medullary syndrome, which is caused by an interruption to the posterior inferior cerebellar artery. It affects several cranial nerve nuclei and the inferior cerebellar peduncle. It causes ipsilateral signs including those listed above and: dysarthria, dysphagia and ataxia. It also causes ipsilateral Horner's syndrome and contralateral loss of spinothalamic tract.
• 29
  A 65-year old man presents with sensory and motor deficit in his legs. He has lost vibration sense on the right and temperature on the left. There is weakness and up-going plantars in the right leg. Where is the lesion most likely to be?
  Difficulty: Hard     Topic: Dissociated sensory loss
  a

  Left internal capsule

  b

  Left medulla

  c

  Right hemi-section of spinal cord

  d

  Left hemi-section of spinal cord

  e

  Centero-posterior spinal cord
  Explanation: This man has Brown-Séquard syndrome, which is caused by a lesion to half of the spinal cord. It results in ipsilateral loss of dorsal columns (vibration and proprioception) and corticospinal tract (upper motor neurone signs and weakness). Plus contralateral loss of spinothalamic tract (pain and temperature) because the pathway decussates at the level it enters the spinal cord.
• 30
  A 65-year old man presents with right arm weakness. He is only strong enough to lift his arm off the bed. What grade strength is this (according to the MRC classification)?
  Difficulty: Medium     Topic: MRC grading of weakness
  a

  2

  b

  3

  c

  4-

  d

  4

  e

  4+
  Explanation: MRC grading of muscle weakness is as follows: 0 = no contraction visible, 1 = flicker of contraction only, 2 = movement but not against gravity, 3 = movement against gravity but with no added resistance, 4 = against resistance but less than normal, 5 = normal for age & gender. 4 is divided into 4-, 4 and 4+ depending on the resistance used.
• 31
  A 53-year old woman with vitiligo presents with night-time falls. She has extensor plantars, with absent knee and ankle jerks. Vibration sense is markedly reduced. What investigation is most likely to give the diagnosis?
  Difficulty: Medium     Topic: Night-falls and vitiligo
  a

  MRI spine

  b

  CT head

  c

  Biopsy and stain with Congo Red

  d

  VDRL test

  e

  Vitamin levels
  Explanation: This woman has subacute combined degeneration of the cord, which occurs due to vitamin B12 deficiency. It causes polyneuropathy with LMN signs as well as SC degeneration with UMN signs. The dorsal columns are lost first, affecting vibration and proprioception. Night-time falls are common due to reduced vision and balance. There are many causes, this woman may have pernicious anaemia, which is associated with vitiligo, and causes a macrocytic anaemia. IV cobalamin is the treatment.
• 32
  Which of the following is not a cause of subacute combined degeneration of the spinal cord?
  Difficulty: Medium     Topic: Subacute combined degeneration of the cord
  a

  Terminal ileal resection

  b

  Achlorhydria

  c

  Isoniazid

  d

  Pernicious anaemia

  e

  Crohn's disease
  Explanation: Combined degeneration of the cord occurs with vitamin B12 (cobalamin) deficiency. Isoniazid causes pyridoxine (vitamin B6) deficiency, which can lead to a polyneuropathy. Vitamin B12 is absorbed only in the terminal ileum, therefore damage from Crohn's disease or resection reduces its uptake. Achlorhydria is lack of reduced gastric acid secretion, which impairs absorption of B12. Dyphyllobothorium is a tapeworm with especially high uptake of B12, causing relatively dietary deficiency. PA causes gastritis and reduced production of intrinsic factor from the stomach, which is required for B12 absorption.