Post-hypoxic myoclonus
(Redirected from Status myoclonicus)
Background
- Myoclonus (irregular muscle contractions) after hypoxic brain injury due to cardiac arrest
- Acute: onset within 48h of injury
- Post-hypoxic myoclonic status: acute myoclonus lasting >30min
- Difficult to control, associated with poor prognosis
- Occurs in 30-40% of comatose cardiac arrest survivors
- Post-hypoxic myoclonic status: acute myoclonus lasting >30min
- Chronic: onset days-weeks after cardiac arrest in patients who regained consciousness (AKA Lance-Adams syndrome)
Clinical Features
- Acute:
- Recent (within 48h) hypoxic brain injury with neuronal necrosis
- Abrupt onset of irregular muscle contractions, focal or generalized
- Post-hypoxic status myoclonus
- Onset usually within 12-24h of injury
- Generalized, multifocal clonus
- Chronic
- Onset days-weeks after arrest
- Awareness preserved
- Typically intention myoclonus
Differential Diagnosis
Evaluation
- EEG (r/o seizure)
- Evaluate for alternative etiologies
Management
- Acute/status
- Difficult and of limited utility
- Consider benzodiazepines, propofol, phenytoin, valproate
- Address goals of care given sign of poor prognosis
- Chronic/lance-adams syndrome
- Valproate, clonazepam, and/or levetiracetam may help control myoclonus