title: Possible impact of stimulus duration on seizure threshold in ECT.
abstract: Seizure thresholds were measured in patients treated with right unilateral electroconvulsive therapy (ECT) using 0.9 amp, 0.5 ms constant current pulses at 30 Hz for 0.93-2.8 s. Using these parameters, only two patients failed to seize at stimulus charges < or = 75.6 mC. Three patients were excluded from further analysis because they experienced generalized motor or electrographic seizures lasting less than 25 s and 30 s, respectively. The remaining 52 patients had a mean seizure threshold of 48.9 +/- 15.3 mC. Seizure threshold was correlated with age, but not sex. These values for seizure threshold are significantly lower than those reported previously using longer pulse-briefer train duration stimuli, suggesting that characteristics of the electrical stimulus influence seizure threshold. These findings have implications for electrical dosing in right unilateral ECT.
authors.affiliation: Washington University School of Medicine, Department of Psychiatry, St. Louis, Missouri.
authors.forename: K G
authors.initials: KG
authors.lastname: Rasmussen
authors.forename: C F
authors.initials: CF
authors.lastname: Zorumski
authors.forename: M R
authors.initials: MR
authors.lastname: Jarvis
mesh_terms: D000328:Adult; D000368:Aged; D000758:Anesthesia; D004565:Electroconvulsive Therapy; D005260:Female; D006801:Humans; D008297:Male; D008723:Methohexital; D008875:Middle Aged; D012640:Seizures / Q000503:physiopathology*; D013390:Succinylcholine; D013997:Time Factors
chemical_list: D008723:Methohexital; D013390:Succinylcholine