Updated 05-May-2020.
Mondo shtuff from around the internet, all about CLONUS!
My botty best at summarizing from Wikipedia: clonus is a series of involuntary, rhythmic, muscular contractions and relaxations . it is accompanied by spasticity (another form of hyperexcitability) the term is from the clonus has also appeared after ingesting potent serotonergic drugs . ingestion strongly predicts imminent serotonin toxicity . self re-excitation requires motor neuron excitability and signaling delay is present due to an increased nerve conduction time . long delays are primarily due to long reflex pathways common in distal joints and muscles . stretch reflex pathway may be stimulated first, and cause a decreased syn clonus is not seen in all patients with spasticity . it is common in muscles with long conduction delays . this theory is still being investigated . only a sustained clonus (5 beats or more) is considered abnormal . Clonus can also be tested in the knees by rapidly pushing the patella (knee cap), towards the toes