Exam 3
A. Neurovascular & Neurotrauma
Hemorrhage, Stroke, Aneurysm
● Hemorrhagic stroke: often from chronic severe HTN; presents with acute neuro deficit
+ headache; management differs from ischemic.
● Ischemic stroke risk: atherosclerosis and atrial fibrillation are classic risks (embolus
→ ischemia).
● Berry aneurysm (circle of Willis): congenital medial wall weakness; rupture →
subarachnoid hemorrhage (worst headache, nuchal rigidity, photophobia). CSF on LP
shows blood/xanthochromia.
● Arteriovenous malformation (AVM): malformed high‑flow shunt with no normal
capillaries; high rupture risk.
Intracranial Pressure (ICP) & Brain Ischemia
● Common ICP causes: vasogenic or cytotoxic edema, obstructive hydrocephalus;
NOT caused by a normal pH.
● Brain ischemia in TBI: mitochondrial dysfunction → ↓ ATP, membrane pump failure.
● Clinical red flags: progressive ↓ LOC, pupillary changes (CN III compression → fixed,
dilated pupil), Cushing triad (late).
Cranial Nerves & Focal Deficits
● CN III (oculomotor): injury/compression → dilated, non‑reactive pupil; ptosis, EOM
deficits.
● Trigeminal neuralgia: vascular compression of CN V causes severe lancinating facial
pain.
● Bell’s palsy (CN VII): acute unilateral lower motor neuron facial weakness; unable to
wrinkle forehead on affected side.
Seizures
● Mechanism: brain focus becomes hyperexcitable and can recruit contralateral
neurons; oxidative stress/free radicals contribute.
● Tonic‑clonic aftermath: postictal somnolence is expected.
Coma & GCS
A. Neurovascular & Neurotrauma
Hemorrhage, Stroke, Aneurysm
● Hemorrhagic stroke: often from chronic severe HTN; presents with acute neuro deficit
+ headache; management differs from ischemic.
● Ischemic stroke risk: atherosclerosis and atrial fibrillation are classic risks (embolus
→ ischemia).
● Berry aneurysm (circle of Willis): congenital medial wall weakness; rupture →
subarachnoid hemorrhage (worst headache, nuchal rigidity, photophobia). CSF on LP
shows blood/xanthochromia.
● Arteriovenous malformation (AVM): malformed high‑flow shunt with no normal
capillaries; high rupture risk.
Intracranial Pressure (ICP) & Brain Ischemia
● Common ICP causes: vasogenic or cytotoxic edema, obstructive hydrocephalus;
NOT caused by a normal pH.
● Brain ischemia in TBI: mitochondrial dysfunction → ↓ ATP, membrane pump failure.
● Clinical red flags: progressive ↓ LOC, pupillary changes (CN III compression → fixed,
dilated pupil), Cushing triad (late).
Cranial Nerves & Focal Deficits
● CN III (oculomotor): injury/compression → dilated, non‑reactive pupil; ptosis, EOM
deficits.
● Trigeminal neuralgia: vascular compression of CN V causes severe lancinating facial
pain.
● Bell’s palsy (CN VII): acute unilateral lower motor neuron facial weakness; unable to
wrinkle forehead on affected side.
Seizures
● Mechanism: brain focus becomes hyperexcitable and can recruit contralateral
neurons; oxidative stress/free radicals contribute.
● Tonic‑clonic aftermath: postictal somnolence is expected.
Coma & GCS
