General Neurology and Neuroscience Foundations
Core concepts
Neurodevelopmental practice rests on a working model of how the nervous system is built and how it fails. Know the sequence of dorsal induction, ventral patterning, neural tube closure (days 22-28), neuronal proliferation, migration, and myelination, and the timing of each so you can date an insult. Understand cortical organization: radial glia guide migration, the cortex forms inside-out, and disruption produces lissencephaly, heterotopia, or polymicrogyria depending on stage. Review neurotransmitter systems (glutamate, GABA, dopamine), the corticospinal and corticobulbar tracts, and the basal ganglia-thalamocortical loops that underlie movement disorders. Sensory and motor pathways, cranial nerve anatomy, and the cerebellar circuitry for coordination are high-yield. Also know basic EEG principles, neuroimaging modalities, and the genetics of inheritance patterns.
Traps
Questions often test timing: a teratogen or hypoxic-ischemic event in the first trimester produces malformations, whereas late-gestational injury produces white matter injury or encephalopathy. Do not confuse upper with lower motor neuron signs. Watch for distractors offering adult-onset degenerative frameworks for a developmental presentation. Another trap is conflating a syndrome's name with its mechanism.
Rule of thumb
Anchor each finding to a developmental epoch. If the lesion is structural and symmetric, think early patterning or metabolic; if focal and asymmetric, think vascular, infectious, or neoplastic.
Worked example: A child with bilateral periventricular nodular heterotopia and epilepsy points to a neuronal migration defect (FLNA-related), not a demyelinating process-migration occurs mid-gestation, so the timing localizes the insult.