Basic Neurosciences: Neuroanatomy, Neurophysiology and Neuropathology
What you must own
Basic science questions reward precise spatial and physiological reasoning, not memorised lists. Anchor neuroanatomy on three axes: long-tract organisation (dorsal columns, spinothalamic, corticospinal), cranial nerve nuclei columns (somatic motor, branchial motor, visceral, general and special sensory), and cerebrovascular territories. Know the functional consequence of a lesion at each point, not just its name.
Neurophysiology: resting membrane potential and the Na/K-ATPase, the ionic basis of the action potential, saltatory conduction and the effect of demyelination, synaptic transmission and neurotransmitter anatomy, cerebrospinal fluid production (choroid plexus, ~500 mL/day, turnover ~3-4 times daily) and the Monroe-Kellie doctrine. Understand autoregulation, the Cushing reflex (hypertension, bradycardia, irregular respiration) and the difference between cytotoxic and vasogenic oedema.
Neuropathology: classify gliomas by lineage and grade (WHO 2021 integrates IDH and 1p/19q status with histology), recognise meningioma variants and their dural tail, and know the classic histology of medulloblastoma, schwannoma (Antoni A/B, Verocay bodies), pituitary adenoma and metastases.
Traps
Questions mix up Wallenberg (lateral medullary, PICA) with medial medullary (anterior spinal artery) syndromes; confuse Broca and Wernicke vascular territories; and test whether oedema is cytotoxic (early ischaemia, intracellular swelling) versus vasogenic (tumour, disrupted blood-brain barrier).
Rule of thumb
For any tract lesion, ask: which side is the body part, and where does the tract cross? Crossing defines the side of the deficit.
Worked example
A patient has right-sided loss of pain and temperature with preserved touch, plus left Horner syndrome and hoarseness. Pain/temperature fibres cross in the cord, so right-sided body loss means a right lateral medullary lesion - the classic PICA syndrome.