These involuntary jerking can be myoclonic jerks which can occur in head, neck, shoulders, arms, legs
and torso. These can occur alone or in combination with
seizure types or epileptic syndromes, absence epilepsy, myoclonic epilepsy, etc. Myoclonus is brief involuntary twitching of a muscle or a group of muscles. It is a medical sign suggestive of underlying nervus system disorders like multiple sclerosis, parkinson’s disease, alzheimer’s disease, serotonin toxicity, some forms of epilepsy.