🧠 Chapter 59: Altered Sensorium

Coma · GCS · Pupillary abnormalities · Ocular reflexes · Herniation syndromes · Management algorithm · Lumbar puncture indications · Intubation criteria · Second-line investigations

🔍 Core Concepts: Altered Sensorium

📌 Definitions
Coma: unarousable unresponsiveness, loss of wakefulness and awareness. Delirium: acute confusional state, fluctuating. Stupor: diminished responsiveness. Brain death: permanent absence of all brain activity including brainstem.
📊 Aetiology Categories
Coma with focal signs (haemorrhage, tumour, stroke). Coma without focal signs or meningeal signs (hypoxia, metabolic, toxins, infections). Coma with meningeal signs (meningitis, encephalitis, SAH).
🩺 GCS (Glasgow Coma Scale)
Eye (1-4), Verbal (1-5), Motor (1-6). GCS ≤8 → severe TBI, consider intubation. GCS <8 + myoclonic jerks at 72h post-arrest → poor neurological outcome.
👁️ Pupillary Findings
Dilated non-reactive: uncal herniation, post-CPR, brainstem injury. Midposition fixed: brain death, midbrain lesions. Constricted: pontine injury, opioids. Reactive pupils generally exclude brainstem death.
⚡ Herniation Syndromes
Uncal: ipsilateral fixed pupil, contralateral hemiparesis. Diencephalic: small reactive pupils, decorticate, Cheyne-Stokes. Midbrain: midposition fixed pupils, decerebrate. Medullary: dilated fixed pupils, irregular breathing.
📋 Management Algorithm
ABCD stabilisation → GCS/pupils → treat herniation (mannitol, hyperventilation, EVD) → first-line labs (glucose, ABG, electrolytes, CT) → LP if no ↑ICP → empirical antibiotics/acyclovir → treat cause.

🩺 Stepwise Approach: Comatose Child

1
Immediate assessment & stabilisation (ABCs)
Airway: GCS <8 → intubate. Breathing: give O2, check EtCO2, treat hypoxia. Circulation: IV access, fluid bolus if hypotensive, vasopressors if shock persists. Check bedside glucose.
2
Neurological examination
GCS score, pupillary size/reaction, oculovestibular/oculocephalic reflexes, motor response (decorticate vs decerebrate). Look for signs of herniation: Cushing triad (hypertension, bradycardia, irregular breathing).
3
Signs of increased ICP / herniation
Immediate measures: elevate head 30°, hyperventilate (target PaCO2 30-35), mannitol 0.5-1 g/kg, hypertonic saline 3%, CSF drainage if EVD present. Urgent CT brain.
4
First-line investigations
Blood glucose (bedside), ABG, lactate, CBC, electrolytes, renal/hepatic function, blood culture, malaria smear. CT brain (plain) to rule out bleed, mass, oedema, herniation.
5
Lumbar puncture (if no contraindications)
Contraindications: signs of ↑ICP, shock, thrombocytopenia, local infection. If LP deferred, give empirical antibiotics (ceftriaxone ± vancomycin) + acyclovir (if HSV suspected).
6
Specific therapies
Bacterial meningitis: antibiotics. Herpes encephalitis: acyclovir. Cerebral malaria: IV artesunate. DKA: fluids/insulin. Hypertensive encephalopathy: antihypertensives. Toxin: naloxone/flumazenil/antivenom.