Raised Intracranial Pressure in Seizures Induced by Electroconvulsive Therapy

Increased intracranial pressure (ICP) can be observed immediately upon seizure activity in craniotomized patients in neurosurgical practice. However, it is not commonly included in models of pathomechanisms contributing to morbidity and mortality in epilepsy. A main contributor to this may be the fact that measuring ICP noninvasively during a seizure is technically challenging. The optic nerve sheath diameter (ONSD) represents a promising, noninvasive option to monitor relative ICP changes. We therefore measured ONSD in patients undergoing electroconvulsive therapy (ECT).

Twenty-seven ECT-induced seizures from nine consecutive patients underwent ONSD measurement at baseline after induction of anesthesia (t0), during injection of suxamethonium (sux) (t1), after injection of sux (t2), during the electrically induced seizure (t3), and after the electrically induced seizure (t4). A linear mixed model was applied.

An increase in ONSD of > 0.2 mm from t0 to t3 was observed in all patients and in all ECT-induced seizures except one. ONSD increased significantly during the succinylcholine-induced fasciculations, T₁, (β = 0.535 mm, p < 0.001) and during the electrically induced seizure, T₃, (β = 1.02 mm, p < 0.001). ONSD returned to baseline after the fasciculations, T₂, (β = 0.091 mm, p = 0.443) and after the seizure, T₄, (β = 0.103 mm, p = 0.379).

This investigation shows generalized convulsive seizures are associated with a transient but pronounced increase in ONSD, suggesting a temporary increase in ICP.