Term information
- UMLS:C1836508
Characterized by a sudden increase in muscle tone whereby the body, arms, or legs make sudden stiffening movements and consciousness is usually preserved. Tonic seizures can occur during sleep. Tonic seizures usually affect both sides of the body, and cause a fall if the affected person was standing when the seizure started.
Generalized seizures with sustained increase in muscle contraction lasting a few seconds to minutes.
A generalized tonic seizure involves bilaterally increased tone of the limbs typically lasting seconds to a minute. They often occur out of sleep and in runs of varying intensity of tonic stiffening. The individual is unaware during these events. At the beginning of tonic seizures with more intense stiffening, individuals may make an expiratory sound. More severe and prolonged tonic seizures may have a vibratory component which may be confused with clonic jerking. Tonic seizures often occur in individuals with intellectual impairment.