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Intermediate Technical IVT

Myoclonic seizure

Pronunciation: MY-oh-klon-ik

A type of seizure characterized by sudden, brief, shock-like muscle jerks that may involve the entire body or specific muscle groups.

Full Definition

Myoclonic seizures are characterized by sudden, brief, shock-like muscle contractions that typically last less than 100 milliseconds. These jerks can be generalized (affecting the whole body) or focal (affecting specific muscle groups), and may occur singly or in clusters. They are commonly seen in juvenile myoclonic epilepsy and other epilepsy syndromes, and can also occur in non-epileptic conditions. The jerks are usually bilateral and symmetric when generalized, and patients typically remain conscious during the event.

Usage

Usage note: Note the distinction between epileptic myoclonus and physiological myoclonus (like hiccups or sleep jerks).

In Context

  • "The teenager reported early morning myoclonic seizures affecting both arms." — Epilepsy clinic assessment
  • "Video-EEG confirmed generalized myoclonic seizures with corresponding polyspike-wave discharges." — Diagnostic report

Also known as

myoclonic jerk myoclonus

Contrasted with

tonic seizure

Don't confuse with

tics tremor startle response

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