EpistemisClonus
Specialty: Neurology.
Why it occurs
- Acute or chronic injury to the pyramidal pathway/upper motor neuron (stroke, traumatic spinal cord injury, brain tumor)
- Multiple sclerosis (active plaque in corticospinal tracts)
- Spastic cerebral palsy
- Acute serotonin syndrome (induced by overexposure to drugs with serotonergic activity)
- Cervical or thoracic degenerative myelopathy with posterior and lateral cord compression
Initial workup
Exploration of clonus through sudden and sustained stretching of a tendon (typically through forced dorsiflexion of the ankle or distal traction of the patella) and quantification of involuntary rhythmic oscillations (considered pathological if it is sustained or asymmetrical); MRI of the brain or spinal cord according to anatomical suspicion; analysis with ions and creatine kinase (CK).
red flags
New onset inexhaustible clonus associated with high fever, altered mental status (confusion, agitation), autonomic instability (diaphoresis, tachycardia) and generalized tremor, characteristic of severe serotonin syndrome, a medical emergency that can lead to rhabdomyolysis and death.
Standard management
- Baclofen — 10-60 mg/day orally, acts by reducing reflex transmission in the spinal cord
- Clonazepam — 0.5-2 mg/day
- Cyproheptadine — 4-12 mg orally, specific serotonin antagonist if the cause is serotonin syndrome
- Intense physiotherapy to maintain ranges of movement and reduce spastic reflex tone.
Educational guidance for study. It is NOT a prescription recommendation. The actual choice depends on the cause, the patient, and current guidelines.
- Area
- Neurology
- Listed causes
- 5
- Treatment options
- 4