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Iraqi Board Neurology study materials
Iraqi Board Neurology study resources

Iraqi Board Neurology: Neuropathology and Basic Neuroscience

Iraqi Board Neurology · Work through your exam, one topic at a time.

All guide sections

Neuropathology and Basic Neuroscience

This domain tests mechanism: what the tissue does after injury and what each inclusion body or tumour marker means. Questions are usually pattern-recognition with a clinical vignette attached.

Cellular reactions to injury

  • Neurons: after 12 to 24 hours of ischaemia they become eosinophilic with a pyknotic nucleus, the classic red neuron, and this change is irreversible.
  • Astrocytes: reactive astrocytosis is GFAP-positive and forms a glial scar, not fibrosis.
  • Microglia: phagocytosis and microglial nodules, prominent in viral encephalitis.
  • Oedema: cytotoxic (intracellular, early ischaemia), vasogenic (blood-brain barrier breakdown with tumour or abscess), interstitial (hydrocephalus).

Inclusion bodies and their diseases

  • Lewy bodies contain alpha-synuclein and define Parkinson disease and dementia with Lewy bodies.
  • Pick bodies are three-repeat tau, with knife-edge frontal and temporal atrophy.
  • Neurofibrillary tangles are hyperphosphorylated tau in Alzheimer disease, starting in entorhinal cortex.
  • Rosenthal fibres and eosinophilic granular bodies belong to pilocytic astrocytoma.
  • Prion disease shows spongiform change and PrPSc deposition without inflammation.

Herniation syndromes

Subfalcine herniation compresses the anterior cerebral artery; uncal herniation dilates the pupil through CN III, then causes contralateral hemiparesis and Duret haemorrhage; tonsillar herniation causes respiratory arrest.

Worked example

A 74-year-old has three years of memory decline followed by a sharp stepwise deterioration after a fall. Imaging shows medial temporal atrophy plus old lacunes. The pathology is best explained by mixed Alzheimer disease and vascular pathology: plaques and tangles plus infarcts. Pure Alzheimer disease would not produce a stepwise course, and pure vascular dementia would not produce prominent hippocampal atrophy.

Traps

Calling gliosis fibrosis; confusing tangles with Lewy bodies; missing prion disease when rapid dementia is accompanied by myoclonus and periodic EEG complexes.