Long Brief Pulse Method for Pulse-wave modified Electroconvulsive Therapy

arXiv:1112.2072v1 [q-bio.NC] 9 Dec 2011 Long Brief Pulse Method for Pulse-wave modified Electroconvulsive Therapy Hiroaki Inomata,1, 2, 3, ∗Hirohiko Harima,1 and Masanari Itokawa1, 3 1Tokyo Metropolitan Matsuzawa Hospital 2Yokohama City University 3Tokyo Metropolitan Institue of Medical Science Modified-Electroconvulsive Therapy (m-ECT) is administered for the treatment of various psy- chiatric disorders. The Seizure Generalization Hypothesis holds that propagation of the induced seizure throughout the whole brain is essential for the effective ECT intervention. However, we encounter many clinical cases where, due to high thresholds, seizure is not induced by the maximum dose of electrical charge. Some studies have indicated that the ultrabrief pulse method, in which pulse width is less than 0.5millisecond (ms), is more effective at inducing seizure than conventional brief pulse (0.5ms-2.0ms). Contrary to the studies, we experienced a case of schizophrenia in which m-ECT with 1.0 and 1.5 ms width pulse (referred to as long brief pulse as 0.5ms width pulse is the default in Japan) succeeded in inducing seizure, whereas ultrabrief pulse failed to induce seizure. This case is described in detail. Moreover, we discuss the underlying mechanism of this phenomenon. Introduction Modified-Electroconvulsive Therapy (m-ECT) is administered for the treatment of various psychiatric disorders. The Seizure Generalization Hypothesis, which underlies the mechanism of ECT, holds that propagation of induced seizure throughout the entire brain is essential for effective ECT intervention[1] . However, there are many clinical cases where, due to high thresholds, seizure is not induced by the maximum dose of electrical charge. In these cases, the following procedures are considered options for inducing seizure; (i) using the older method of sine-wave ECT (ii) promoting hyperventilation in patients [2] (iii) using anesthetic agents such as ketamine with ECT [2]. However, these are not standard methods as sine-wave ECT induces more severe side effects than pulse-wave ECT, and not all anesthesiologists are fully trained in the latter two procedures. Recently randomized control trials focusing on pulse width have been conducted[3, 4]. Sackeim et al [3] reported that the ultrabrief pulse method, in which pulse width is less than 0.3millisecond (ms), induces more therapeutic effects and fewer side effects and requires less electrical charge to induce seizure compared to conventional brief pulse (1.5ms). It could be predicted then that the ultrabrief pulse would be more effective in inducing seizure in patients with high thresholds. Contrary to this, we experienced a case of schizophrenia in which m-ECT with 1.0 and 1.5ms width pulse (referred to as long brief pulses as 0.5ms width pulse is the default in Japan) succeeded in inducing seizure, whereas ultrabrief pulse failed. We present this case in detail and discuss the possible underlying mechanisms. Written informed consent was obtained from the patient and his wife (legal guardian). All personal information has been anonymized. Case presentation The patient is a 35-year-old schizophrenic Japanese male. His history of illness started at age 23 with symptoms of auditory hallucinations, persecutory delusions and psychomotor excitement. Subsequently these symptoms relapsed every one to three years. He was discharged from hospital three years ago and was being followed as an outpatient. One month ago, he complained to his doctor that he was being watched by strangers. The atypical antipsychotic blonanserine and the mood stabilizer valproate were added to his medication but these produced the persecutory delusion that the new therapy was part of an experiment instigated by his doctor. He became aggressive with verbal threats and was admitted to our hospital due to a lack of available beds in his regular treating hospital. On admission, he was psychotic and extremely agitated, and needed to be restrained. He initially refused treatment but eventually agreed to his old treatment regime excluding blonanserine and valproate. His medical history revealed ∗Electronic address: inomatah0612@gmail.com 2 that medication was of little effect for his relapsed symptoms while m-ECT was effective, although sine-wave ECT was necessary due to his high threshold. The presence of brain disease such as tumours was excluded after review of Computed-Tomography images. ECT treatment was instigated three days post admission. For the ECT interventions, we used a Somatic Thymatron ECT device, placing electrodes in a bitemporal configuration and administering propofol at 1.0mg/kg as an anesthetic induction and succinylcholin at 1.0 mg/kg as a muscle relaxant. Figure 1 shows the clinical course of this patient. In trials 1 to 3, we used a LOW 0.5 setting, in which the pulse width is fixed at 0.5ms, but this failed to induce seizure at the maximum dose of electrical charge (504 milicoulomb). We then changed the Thymatron setting

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