According to the International League Against Epilepsy’s (ILAE) classification, Generalised Tonic-clonic seizures may now be referred as Bilateral Tonic-clonic seizures.

These are seizures with a sudden and brutal start, also marked by a cry (epileptic cry), a fall that may induce bruises, and an immediate and total loss of consciousness. It can be divided into three stages.

The tonic phase

The tonic phase (usually 10 to 20 sec.) characterised by an intense and generalised contraction of all limbs muscles as well as the thoracic, facial and abdominal ones. As a consequence the person may experience an apnoea with cyanosis and even tongue biting. In children, the tonic phase is shorter and less intense than in adults.

The clonic phase

The clonic phase (variable duration) characterised by the occurrence of sudden, generalised, synchronic muscle spasm contractions (“jerks”). At first, these jerks have a very high frequency. Then this frequency decreases. In children the clonic phase is more prolonged than in adults.

The post-critical phase

The post-critical phase, characterised by a coma combined with a generalised muscular relaxation, stertorius breathing, and enuresis marking the end of the seizure. The end of the seizure may be followed by a state of confusion.

For references, please access “Dravet Syndrome/ Tonic-clonic seizures” though the the Bibliography part available in the resources tab