MRCP Part 1 Gastroenterology & Neurology 2 — Questions and Answers
Question 1: A 30-year-old woman presents with a sudden severe headache she describes as 'the worst of her life', photophobia, and a normal CT head. What is the next investigation?
- MRI brain
- Lumbar puncture (Correct answer)
- EEG
- CT angiography
Correct answer: Lumbar puncture
A 'thunderclap' headache with negative CT requires lumbar puncture to exclude subarachnoid haemorrhage (SAH). LP should be performed at least 12 hours after onset to allow xanthochromia (bilirubin from haemolysed red cells) to develop. CT alone misses approximately 5% of SAH.
Question 2: Which pattern of inheritance does Huntington's disease follow?
- Autosomal recessive
- X-linked recessive
- Autosomal dominant (Correct answer)
- Mitochondrial
Correct answer: Autosomal dominant
Huntington's disease is caused by a CAG trinucleotide repeat expansion in the HTT gene on chromosome 4, following autosomal dominant inheritance. Anticipation occurs — subsequent generations may be affected at an earlier age with longer repeat lengths.
Question 3: A 65-year-old man presents with resting tremor, bradykinesia, and rigidity. Dopamine transporter (DAT) imaging shows reduced uptake in the striatum. What is the diagnosis?
- Essential tremor
- Parkinson's disease (Correct answer)
- Wilson's disease
- Drug-induced tremor
Correct answer: Parkinson's disease
Parkinson's disease is characterised by the triad of resting tremor, bradykinesia, and rigidity (plus postural instability), with reduced dopaminergic neurone activity in the substantia nigra. DAT scan (DaTSCAN) shows reduced striatal dopamine transporter uptake, distinguishing it from essential tremor.
Question 4: A 40-year-old woman has episodic, unilateral, throbbing headaches lasting 4–72 hours, associated with nausea, photophobia, and preceded by visual zigzag lines. What is the diagnosis?
- Tension-type headache
- Cluster headache
- Migraine with aura (Correct answer)
- Subarachnoid haemorrhage
Correct answer: Migraine with aura
Migraine with aura is characterised by reversible neurological symptoms preceding the headache (aura), including visual disturbances (scintillating scotoma, fortification spectra). The headache is unilateral, throbbing, 4–72 hours, with nausea/vomiting and photo/phonophobia. It meets ICHD-3 criteria.
Question 5: Which antibody is associated with myasthenia gravis?
- Anti-Jo-1
- Anti-AChR (acetylcholine receptor antibody) (Correct answer)
- Anti-dsDNA
- Anti-Ro/La
Correct answer: Anti-AChR (acetylcholine receptor antibody)
Myasthenia gravis is an autoimmune neuromuscular junction disorder caused in approximately 85% of cases by anti-acetylcholine receptor (AChR) antibodies that block, accelerate degradation, or destroy AChR at the postsynaptic membrane. Anti-MuSK antibodies account for most seronegative cases.
Question 6: A 55-year-old woman presents with sudden-onset right-sided hemiplegia and expressive aphasia. CT head is normal. What is the most likely diagnosis and what immediate treatment is indicated?
- Complex migraine — manage with analgesia
- Ischaemic stroke — IV alteplase thrombolysis within 4.5 hours if no contraindications (Correct answer)
- Haemorrhagic stroke — urgent neurosurgical referral
- Todd's paresis — observe only
Correct answer: Ischaemic stroke — IV alteplase thrombolysis within 4.5 hours if no contraindications
Sudden focal neurological deficit (hemiplegia, aphasia) in the absence of CT haemorrhage indicates likely ischaemic stroke. IV alteplase is indicated within 4.5 hours of symptom onset if there are no contraindications (no haemorrhage, no major surgery, BP controlled). Every minute counts — time is brain.
MRCP Part 1 Gastroenterology & Neurology 2
A 30-year-old woman presents with a sudden severe headache she describes as 'the worst of her life', photophobia, and a normal CT head.
What is the next investigation?