Basic Science and Pathophysiology

Seizures result from rapid abnormal electrical discharges from cerebral neurones. This is thought to arise from an imbalance between excitatory and inhibitory neurotransmitters, most commonly between glutamate and gamma-aminobutyric acid (GABA), leading to a failure of the inhibitory process [7].

Numerous systemic and metabolic changes occur in association with prolonged seizures. These include:

• Tachycardia

• Hypertension

• Hyperglycaemia

• Lactic acidosis

Most of these changes are thought to result from a surge in catecholamine release that accompanies the seizure and the changes will resolve with seizure resolution.

Beyond 30 minutes of seizure duration, cerebral autoregulation may become impaired and cerebral perfusion will fall as hypotension occurs, with potential for ischaemic injury and cerebral oedema.