MRCP Part 1 Neurology and Psychiatry

Question 1

A 30-year-old woman presents with optic neuritis. MRI brain shows periventricular white matter lesions. CSF shows oligoclonal bands not matched in serum. What is the most likely diagnosis?

Accepted Answer

Multiple sclerosis

Answer

Multiple sclerosis (MS) is characterised by demyelinating lesions disseminated in time and space. Optic neuritis is a common presenting feature, and periventricular white matter lesions on MRI with unmatched CSF oligoclonal bands strongly support the diagnosis according to the McDonald criteria.

Question 2

A 72-year-old man presents with a resting tremor, bradykinesia, and rigidity. Which neurotransmitter deficiency is primarily responsible?

Accepted Answer

Dopamine

Answer

Parkinson's disease results from degeneration of dopaminergic neurones in the substantia nigra pars compacta, leading to dopamine deficiency in the nigrostriatal pathway. The cardinal features are resting tremor, bradykinesia, rigidity, and postural instability.

Question 3

A patient presents with sudden onset worst headache of their life, neck stiffness, and photophobia. CT head is normal. What is the next most appropriate investigation?

Accepted Answer

Lumbar puncture (after 12 hours from onset)

Answer

When subarachnoid haemorrhage (SAH) is suspected but CT head is negative (sensitivity drops after 6 hours), lumbar puncture should be performed at least 12 hours after symptom onset to allow time for xanthochromia to develop. Xanthochromia (yellow discolouration from bilirubin) distinguishes SAH from a traumatic tap.

Question 4

A 65-year-old right-handed man suddenly develops expressive dysphasia with comprehension preserved. He can understand commands but struggles to produce fluent speech. Which area of the brain is most likely affected?

Accepted Answer

Broca's area (left inferior frontal gyrus)

Answer

Broca's area, located in the left inferior frontal gyrus (in right-handed individuals), is responsible for speech production. Damage causes expressive (non-fluent) dysphasia where comprehension is preserved but speech output is effortful and telegraphic.

Question 5

A 25-year-old woman presents with episodic severe unilateral headache with visual aura lasting 20 minutes followed by nausea and photophobia. She has 4 attacks per month. What is the most appropriate prophylactic medication?

Accepted Answer

Propranolol

Answer

Propranolol is a first-line prophylactic agent for migraine recommended by NICE. Prophylaxis is considered when patients have 4 or more attacks per month. Topiramate and amitriptyline are alternatives. Sumatriptan is an acute treatment, not prophylaxis.

MRCP Part 1 Practice Test

MRCP Part 1 Practice Test

MRCP Part 1 Neurology and Psychiatry