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Intermediate Technical IVT

generalized tonic-clonic seizure

A seizure type involving initial muscle stiffening (tonic phase) followed by rhythmic jerking (clonic phase) affecting the entire body.

Full Definition

A generalized tonic-clonic seizure, formerly called grand mal seizure, is characterized by two distinct phases affecting the entire brain simultaneously. The tonic phase involves sudden loss of consciousness and generalized muscle stiffening lasting 10-30 seconds, often causing the patient to fall. This is followed by the clonic phase, featuring rhythmic jerking movements of all limbs that gradually decrease in frequency over 1-3 minutes. Post-ictal confusion and fatigue typically follow, and the seizure may be preceded by warning signs or aura in some patients.

Usage

Usage note: Preferred term over 'grand mal seizure' in modern medical writing. Hyphenate when used as compound adjective.

In Context

  • "The 8-year-old presented with her first generalized tonic-clonic seizure lasting approximately 90 seconds." — Clinical note
  • "Medication adherence is crucial for preventing breakthrough generalized tonic-clonic seizures." — Patient education material

Also known as

GTCS grand mal seizure tonic-clonic seizure

Contrasted with

absence seizure focal seizure

Don't confuse with

complex partial seizure tonic seizure clonic seizure

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