Master Neurology
for PLAB 1

Core Concepts

Neurology involves the study and treatment of disorders of the nervous system (brain, spinal cord, peripheral nerves, muscles). Key principles include localisation of lesions (where the problem is) and understanding the distinction between Upper Motor Neuron (UMN) and Lower Motor Neuron (LMN) signs. Common presenting symptoms include weakness, sensory changes, visual disturbances, headaches, seizures, gait abnormalities, and cognitive decline.

Clinical Presentation

• Stroke (Ischaemic/Haemorrhagic): Sudden onset focal neurological deficit (e.g., unilateral weakness, speech disturbance, visual loss). Use F.A.S.T. acronym (Face drooping, Arm weakness, Speech difficulty, Time to call emergency).
• Epilepsy: Recurrent unprovoked seizures. Can be focal (affecting one part of the brain, e.g., limb jerking, sensory changes, altered awareness) or generalised (e.g., tonic-clonic with loss of consciousness, stiffening then jerking). Post-ictal confusion/drowsiness is common.
• Parkinson's Disease: Chronic progressive neurodegenerative disorder. Cardinal features: Tremor (resting, often pill-rolling), Rigidity (cogwheel), Akinesia/Bradykinesia (slow movement), Postural instability.
• Multiple Sclerosis (MS): Autoimmune demyelinating disease of CNS. Often presents in young adults (20-40s) with relapsing-remitting course. Symptoms vary widely: optic neuritis (painful unilateral vision loss), sensory symptoms (numbness, tingling, Lhermitte's sign), motor weakness, fatigue, ataxia, bladder dysfunction.
• Headaches:
  • Migraine: Unilateral, throbbing, moderate-severe, often with aura (visual, sensory), photophobia, phonophobia, nausea/vomiting.
  • Tension-Type: Bilateral, pressing/tightening, mild-moderate, not worsened by routine physical activity.
  • Cluster: Severe unilateral orbital/periorbital pain, excruciating, with ipsilateral autonomic features (ptosis, miosis, lacrimation, conjunctival injection, rhinorrhoea).
• Myasthenia Gravis: Autoimmune disorder of neuromuscular junction. Fluctuating muscle weakness that worsens with activity and improves with rest. Common: ptosis, diplopia, dysphagia, fatigable limb weakness.
• UMN vs LMN Lesions:
  • UMN: Weakness, spasticity (increased tone), hyperreflexia, Babinski's sign positive.
  • LMN: Weakness, flaccidity (decreased tone), hyporeflexia/areflexia, muscle atrophy, fasciculations.

Diagnosis (Gold Standard)

• Stroke: CT head (non-contrast) is first-line to rule out haemorrhage. MRI brain (diffusion-weighted imaging) is gold standard for ischaemic stroke.
• Epilepsy: Primarily clinical diagnosis based on detailed history from patient and witnesses. EEG supports diagnosis but normal EEG does not exclude epilepsy.
• Parkinson's Disease: Clinical diagnosis based on cardinal motor features. DAT scan (Dopamine Transporter Scan) can support diagnosis in uncertain cases but is not routine.
• Multiple Sclerosis: MRI brain and spinal cord (showing dissemination in space and time) is key. CSF analysis showing oligoclonal bands and elevated IgG index can be supportive.
• Myasthenia Gravis: Acetylcholine Receptor (AChR) antibody testing. EMG (repetitive nerve stimulation showing decremental response) can also be used.
• Subarachnoid Haemorrhage (SAH): CT head (non-contrast). If CT negative but high suspicion, Lumbar Puncture for xanthochromia (after 6-12 hours post-onset).

Management (First Line)

• Ischaemic Stroke:
  • Acute: IV thrombolysis (alteplase) within 4.5 hours of symptom onset for eligible patients. Mechanical thrombectomy for large vessel occlusion within 6-24 hours.
  • Secondary Prevention: Antiplatelets (aspirin, clopidogrel), statins, blood pressure control, lifestyle modification.
• Haemorrhagic Stroke: Blood pressure control, neurosurgical consultation for potential evacuation/ventriculostomy. Reversal of anticoagulation if applicable.
• Epilepsy: Anti-epileptic drugs (AEDs) are first-line. Choice depends on seizure type (e.g., Carbamazepine/Lamotrigine for focal, Valproate/Levetiracetam for generalised). Status epilepticus: IV lorazepam/diazepam then IV phenytoin/levetiracetam.
• Parkinson's Disease: Levodopa (most effective for motor symptoms). Dopamine agonists (ropinirole, pramipexole) and MAO-B inhibitors (selegiline, rasagiline) for earlier disease or as adjuncts.
• Multiple Sclerosis:
  • Acute Relapse: High-dose corticosteroids (e.g., IV methylprednisolone).
  • Disease Modification: Immunomodulatory/immunosuppressive drugs (e.g., interferon betas, glatiramer acetate, natalizumab, ocrelizumab).
• Migraine:
  • Acute: NSAIDs, triptans (e.g., sumatriptan).
  • Prophylaxis (if frequent/severe): Beta-blockers (propranolol), topiramate, amitriptyline.
• Myasthenia Gravis: Acetylcholinesterase inhibitors (e.g., pyridostigmine). Immunosuppression (corticosteroids, azathioprine). Myasthenic crisis: IVIg or plasma exchange.

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