Anoxic & Hypoxic Brain Injury: Causes, Consequences & Rehabilitation

Definitions

• Anoxic brain injury: Complete oxygen deprivation (cardiac arrest, asphyxiation, severe hemorrhage). Neuronal death begins within ~4 minutes.
• Hypoxic brain injury: Partial oxygen reduction (respiratory failure, CO poisoning, severe anemia, hypotension). Damage proportional to depth and duration.

Common Causes

Anoxic	Hypoxic
Cardiac arrest	Severe asthma/COPD exacerbation
Drowning	Carbon monoxide poisoning
Choking/airway obstruction	High-altitude exposure
Exsanguination	Severe anemia
Anesthesia complication	Drug overdose (opioids, sedatives)

Neurological Sequelae

• Cognitive: memory, attention, executive dysfunction
• Motor: spasticity, ataxia, myoclonus (Lance-Adams syndrome)
• Speech/language: aphasia, dysarthria
• Behavioral: disinhibition, apathy, psychosis
• Vegetative/minimally conscious states (severe anoxia)

Acute Management

1. Restore oxygenation/circulation (CPR, ACLS, intubation, vasopressors)
2. Targeted temperature management (32–36°C × 24 hours) post-cardiac arrest
3. Seizure prophylaxis/treatment (EEG monitoring)
4. Neuroimaging (MRI DWI for prognosis)

Rehabilitation & Long-Term Care

Interdisciplinary: physiatry, PT/OT/SLT, neuropsychology, vocational rehab. Neuroplasticity-driven recovery peaks at 3–6 months but continues for years. Family training, community reintegration, and advance care planning are essential.