Neurological Emergencies in ICU

Raised ICP & Herniation - Skull's Squeeze

• Normal ICP < 15 mmHg; Pathological > 20-25 mmHg.
• Monro-Kellie Doctrine: Brain (80%), Blood (10%), CSF (10%) in fixed skull.
• $CPP = MAP - ICP$; Target 60-70 mmHg. Low CPP → ischemia.
• Signs: Headache, vomiting, ↓LOC, papilledema.
• 📌 Cushing's Triad (late): Hypertension, Bradycardia, Irregular respirations.
• Herniation Syndromes:
  • Subfalcine: Cingulate gyrus under falx.
  • Uncal (Transtentorial): Medial temporal lobe → tentorial hiatus.

    ⭐ Uncal: Ipsilateral CN III palsy (fixed dilated pupil), contralateral hemiparesis (Kernohan's notch phenomenon: ipsilateral).

  • Central (Transtentorial): Diencephalon, midbrain downward.
  • Tonsillar (Foraminal): Cerebellar tonsils → foramen magnum.
• Management: Stepwise approach.

Status Epilepticus - Brain on Fire

• Definition: Seizure >5 min OR ≥2 seizures, no full recovery between.
• Goal: Rapid termination to prevent neuronal injury.
• Types: Convulsive (GCSE), Non-Convulsive (NCSE).

• cEEG for Refractory SE (RSE) & suspected NCSE.

⭐ NCSE: suspect in unexplained Altered Mental Status (AMS) in ICU.

Acute Stroke in ICU - Clot & Bleed Chaos

📌 FAST (Face, Arms, Speech, Time) for rapid recognition. ICU: Stabilize (ABC), prevent secondary injury (edema, ↑ICP, seizures), manage complications.

⭐ Hemorrhagic transformation is a feared complication of thrombolysis for ischemic stroke, occurring in ~6% of patients receiving IV alteplase for acute ischemic stroke an can lead to significant worsening of neurological outcome or death.

Coma & Delirium - Mind Adrift

Coma: Unarousable. GCS < 8 → Intubate.

• Glasgow Coma Scale (GCS):

  Comp.	Response	Score
  Eye	Spont/Speech/Pain/None	4/3/2/1
  Verbal	Orient/Conf/Inappr/Sound/None	5/4/3/2/1
  Motor	Obeys/Local/Withdraw/Flex/Ext/None	6/5/4/3/2/1
  Total: 3-15

• Approach to Coma:

• Causes (Coma): 📌 AEIOU-TIPS (Alcohol, Epilepsy, Infection, Overdose, Uremia, Trauma, Insulin, Psych, Stroke).

Delirium: Acute, fluctuating attention/awareness.

• Screen: CAM-ICU.
• Causes (Delirium): 📌 I WATCH DEATH (Infection, Withdrawal, Acute metabolic, Trauma, CNS, Hypoxia, Deficiencies, Endocrine, Acute vascular, Toxins, Heavy metals).
• Manage: Treat cause, non-pharma, cautious haloperidol.

⭐ The Confusion Assessment Method for the ICU (CAM-ICU) is a validated tool for delirium screening.

High‑Yield Points - ⚡ Biggest Takeaways

• GCS < 8 often requires intubation; crucial for neurological assessment.
• Cushing's triad (hypertension, bradycardia, irregular respirations) signals ↑ ICP.
• Manage ↑ ICP: head up (30°), mannitol/hypertonic saline, controlled hyperventilation.
• Status epilepticus (>5 min): IV lorazepam first, then phenytoin/fosphenytoin.
• Meningitis/Encephalitis: Early LP (if safe) & empiric antimicrobials are critical.
• Acute ischemic stroke: Thrombolysis/thrombectomy if eligible and within window.
• Brain death: Confirmed by coma, absent brainstem reflexes, and positive apnea test.