Fosphenytoin pre-medication for pediatric extra-operative electrical stimulation brain mapping.

Abstract

PURPOSE:

We studied the effect of fosphenytoin (FOS) pre-medication on the incidence and thresholds of after-discharges (ADs), seizures, and functional responses during electrical stimulation mapping (ESM).

METHODS:

As individualized by the attending epileptologist, FOS was given intravenously at 2 mg-phenytoin-equivalents (PE)/kg/min or 150 mg-PE/min (whichever slower). Patients who received and did not receive FOS were compared for the incidence and thresholds of ADs, seizures, and functional responses.

RESULTS:

Before ESM, 40 and 82 patients respectively were pre-medicated/not pre-medicated with FOS. The incidence of ESM-induced seizures was significantly lower in FOS pre-medicated patients (22.5% vs. 42.7%, p = 0.044), whereas temporal language threshold was higher (9.2 vs. 6.5 mA, p = 0.032). FOS was more efficacious in preventing ESM-induced seizures in patients with symptomatogenic zone ipsilateral to the side of ESM. Although FOS dose had no significant effect on minimum language, minimum motor, or AD thresholds; seizure and temporal language thresholds showed trends approaching significance, intersecting at 12.2 mg-PE/kg. The incidence of ESM-induced seizures was significantly lower in those who received FOS at a dose of ≤12 mg/kg (9.1%) compared to those who did not receive any FOS (42.7%, p = 0.046), while the temporal language thresholds were not significantly different (6.3 vs. 6.5 mA, p = 0.897).

CONCLUSIONS:

This study provides class III evidence that FOS pre-medication before ESM decreases the incidence of ESM-induced seizures, but increases temporal language threshold. FOS pre-medication may thus be considered before ESM. Future studies should prospectively verify these observations and characterize dose-response relationships.

• Authors: Ravindra Arya, Gewalin Aungaroon, Alonso Zea Vera, Paul S Horn, Anna W Byars, Hansel M Greiner, Francesco T Mangano, Katherine D Holland
• Journal: Epilepsy research (Epilepsy Res) Vol. 140 Pg. 171-176 (02 2018) ISSN: 1872-6844 [Electronic] Netherlands
• PMID: 29367180 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)
• Copyright: Copyright © 2018 Elsevier B.V. All rights reserved.

Chemical References

• Sodium Channel Blockers
• Phenytoin
• fosphenytoin

Topics

• Administration, Intravenous
• Brain Mapping (methods)
• Child
• Drug Resistant Epilepsy (diagnosis, physiopathology)
• Electric Stimulation (methods)
• Electrocorticography (methods)
• Female
• Humans
• Language
• Male
• Phenytoin (administration & dosage, analogs & derivatives)
• Retrospective Studies
• Seizures (diagnosis, etiology, physiopathology)
• Sodium Channel Blockers (administration & dosage)