Tonic-clonic seizures Tonic-clonic (grand mal) is the most recognised form of convulsive seizure. Tonic-clonic seizures are where the child may go rigid and fall down, sometimes with an involuntary high cry or shriek. This is caused by air being forced out of the lungs and through the larynx in spasms as the muscles relax and tighten rhythmically, causing the child to jerk in convulsions. This can be very upsetting to watch, as the person may breathe with difficulty due to the fact that the respiratory muscles are also involved in the stiffening process. The child may turn blue in the face, foam at the mouth, bite the inside of the cheek or tongue, grunt or be incontinent. Surprisingly, the child affected is unaware of what is happening, though they may feel tired, confused or have a headache when they come round. There is also a possibility that they may have injured themselves when falling, and will more than likely need to rest in order to recover fully.