Master Neurology
for PLAB 1

What the PLAB 1 Tests in Neurology

Neurology in PLAB 1 tests the ability to localise lesions, recognise common neurological emergencies, and initiate appropriate management. Candidates must differentiate stroke subtypes (ischaemic vs haemorrhagic) using the ROSIER score and know the 4.5-hour thrombolysis window for alteplase. Key presentations include headache (migraine, tension-type, cluster, subarachnoid haemorrhage), seizures (generalised vs focal, status epilepticus management with lorazepam), Parkinson’s disease (triad of tremor, rigidity, bradykinesia; first-line levodopa/carbidopa or dopamine agonists), and multiple sclerosis (relapsing-remitting, McDonald criteria, first-line interferon or glatiramer). Peripheral nerve disorders (Guillain-Barré, nerve conduction studies, IVIG or plasma exchange) and myasthenia gravis (anti-AChR antibodies, edrophonium test, pyridostigmine) are high-yield. Meningitis/encephalitis differentiation (CSF glucose, protein, WBC count) and emergency management of raised intracranial pressure (mannitol, dexamethasone) are tested.

High-Yield Concepts

• Stroke Thrombolysis Criteria: Alteplase (0.9 mg/kg IV, max 90 mg) given within 4.5 hours of symptom onset. Exclusion: INR >1.7, platelets <100, systolic BP >185 mmHg, recent major surgery, or intracranial haemorrhage on CT. Use ROSIER score: facial droop (1), arm drift (1), speech disturbance (1) – score ≥1 suggests stroke.
• Status Epilepticus Management: First-line: IV lorazepam 0.1 mg/kg (max 4 mg) or IM midazolam 10 mg if no IV access. Second-line: IV phenytoin 18 mg/kg (max 1 g) or levetiracetam 60 mg/kg. Refractory: propofol or thiopental with EEG monitoring. Check glucose (50 mL 50% dextrose if <3 mmol/L).
• Meningitis CSF Findings: Bacterial: low glucose (<2.2 mmol/L), high protein (>1 g/L), neutrophil-predominant WBC (>1000 cells/µL). Viral: normal glucose, mild protein rise, lymphocytosis. Tuberculous: low glucose, very high protein, lymphocytosis. Empirical antibiotics: ceftriaxone 2 g IV plus vancomycin (if resistant pneumococcus) and dexamethasone 0.15 mg/kg before antibiotics.
• Parkinson’s Disease First-Line Treatment: For motor symptoms: levodopa/carbidopa (co-beneldopa) is most effective. Dopamine agonists (ropinirole, pramipexole) used in younger patients (<60) to delay motor complications. Anticholinergics (procyclidine) for tremor-predominant disease. Monitor for impulse control disorders with agonists.
• Guillain-Barré Syndrome Diagnosis and Management: Ascending flaccid paralysis, areflexia, albumin-cytologic dissociation on CSF. Nerve conduction studies show demyelination. Treatment: IVIG 0.4 g/kg/day for 5 days or plasma exchange. Monitor FVC and bulbar function; intubation if FVC <20 mL/kg or declining. Avoid steroids.
• Myasthenia Gravis Diagnosis: Anti-acetylcholine receptor antibodies positive in 80%. Edrophonium (Tensilon) test: 2 mg IV test dose, then 8 mg – transient improvement in ptosis or diplopia. First-line: pyridostigmine 60 mg TDS. Thymectomy if thymoma present. Avoid aminoglycosides, beta-blockers, and magnesium.
• Subarachnoid Haemorrhage: Sudden thunderclap headache, neck stiffness, vomiting. CT head within 6 hours: sensitivity >98%. If CT negative, perform lumbar puncture for xanthochromia (bilirubin). Management: nimodipine 60 mg Q4H for 3 weeks to prevent vasospasm, neurosurgical clipping or endovascular coiling.
• Multiple Sclerosis McDonald Criteria: Requires dissemination in space (≥2 MRI lesions in typical areas: periventricular, juxtacortical, infratentorial, spinal cord) and time (new lesion on follow-up MRI or simultaneous gadolinium-enhancing and non-enhancing lesions). First-line DMT: interferon beta-1a or glatiramer acetate. Relapse: IV methylprednisolone 1 g/day for 3-5 days.

Common Traps in Neurology Questions

• Confusing ischaemic with haemorrhagic stroke: remember haemorrhagic stroke often has headache, vomiting, and hypertension; CT without contrast is definitive.
• Giving glucose before thiamine in suspected Wernicke’s encephalopathy: always give IV thiamine 100 mg first to prevent precipitating Korsakoff psychosis.
• Using lumbar puncture in suspected raised ICP without prior CT: contraindicated if papilloedema, focal signs, or GCS <13 due to risk of coning.
• Treating Bell’s palsy with steroids alone: add acyclovir if severe (House-Brackmann grade IV or V) or if Ramsay Hunt syndrome (vesicles in ear) suspected.
• Assuming all headache with fever is meningitis: consider cerebral malaria (if travel history), typhoid, or sinusitis; check CSF only after ruling out contraindications.

How to Revise Neurology for the PLAB 1

Focus on acute neurological presentations: stroke, seizure, headache, and altered consciousness. Questions often present a clinical scenario with a key decision point (e.g., thrombolysis eligibility, choice of IVIG vs steroids, need for CT before LP). Memorise CSF profiles for meningitis, stroke thrombolysis exclusion criteria, and status epilepticus drug doses. Practise applying the ROSIER score and the Glasgow Coma Scale. Be ready to interpret basic CT head findings (hyperdense MCA sign, haemorrhage, midline shift). Review the UK guidelines from NICE for stroke and epilepsy. Time management: allocate more time to scenarios with multiple-choice options that test stepwise management rather than rare diseases.

Practise it: MedLumen has 49 Neurology questions for the PLAB 1, each with a full explanation and references.