title: Seizure threshold and the half-age method in bilateral electroconvulsive therapy in Japanese patients.
abstract: OBJECTIVE
  Seizure threshold (ST) in electroconvulsive therapy (ECT) has not been reported previously in Japanese patients. We investigated ST in bilateral ECT in Japanese patients using the dose-titration method. The associations between demographic and clinical characteristics and ST were analyzed to identify the predictors of ST. Finally, the validity of the half-age method for the stimulus dose was evaluated.
  
  
  METHODS
  Fifty-four Japanese patients with mood disorder, schizophrenia, and other psychotic disorders received an acute course of bilateral ECT using a brief-pulse device. ST was determined at the first session using a fixed titration schedule. ST was correlated with age, sex, body mass index, history of previous ECT, and psychotropic drugs on multiple regression analysis. Furthermore, the rate of accomplished seizures was calculated using the half-age method.
  
  
  RESULTS
  Mean ST was 136 mC. ST was influenced by age, sex, history of previous ECT, and medication with benzodiazepines. The accomplished seizure rate using the half-age method was 72%, which was significantly lower in men and subjects on benzodiazepines.
  
  
  CONCLUSIONS
  ST in Japanese patients was equal to or slightly higher than that previously reported in other ethnic groups, which might be attributable, at least in part, to high prevalence of and large-dose benzodiazepine prescription. Higher age, male gender, no history of ECT, and benzodiazepines were related to higher ST. The half-age method was especially useful in female patients and subjects without benzodiazepine medication.
authors: Department of Neuropsychiatry, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Japan.
authors: Kazuyuki
authors: K
authors: Yasuda
authors: Kaoru
authors: K
authors: Kobayashi
authors: Masayasu
authors: M
authors: Yamaguchi
authors: Koichi
authors: K
authors: Tanaka
authors: Tomokazu
authors: T
authors: Fujii
authors: Yuichi
authors: Y
authors: Kitahara
authors: Toshio
authors: T
authors: Tamaoki
authors: Yutaka
authors: Y
authors: Matsushita
authors: Akihiko
authors: A
authors: Nunomura
authors: Nobutaka
authors: N
authors: Motohashi
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001569:Benzodiazepines / Q000627:therapeutic use*; D004565:Electroconvulsive Therapy / Q000379:methods*; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D019964:Mood Disorders / Q000628:therapy*; D011618:Psychotic Disorders / Q000628:therapy*; D012559:Schizophrenia / Q000628:therapy*; D012640:Seizures; D012684:Sensory Thresholds / Q000187:drug effects / Q000502:physiology*; D012737:Sex Factors; D055815:Young Adult
chemical_list: D001569:Benzodiazepines
keywords: Japanese; dosing strategy; electroconvulsive therapy; race; seizure threshold