Biomedical subjects

Nobutaka Motohashi

Publications and source records attributed to Nobutaka Motohashi.

6 recordsLinked to original sources

PubMed2006

Effects of repetitive transcranial magnetic stimulation on [11C]raclopride binding and cognitive function in patients with depression.

BACKGROUND: Several studies have demonstrated that repetitive transcranial magnetic stimulation (rTMS) elicits moderate antidepressant effects. Several previous studies suggested that the dopaminergic system might be related to this therapeutic action of rTMS. We attempted to determine the effects of chronic rTMS on central dopaminergic function in depression using positron emission tomography (PET) with [11C]raclopride. METHODS: Nine patients with depression were treated with 10 daily sessions of rTMS (10 Hz, 5 s train, 20 trains at 100% motor threshold per session) over the left dorsolateral prefrontal cortex (DLPFC). Each patient underwent two [11C]raclopride PET scans and neuropsychological tests - before rTMS and 1 day after rTMS. RESULTS: In five patients, the Hamilton Rating Scale for Depression (HRSD) significantly decreased. Patients showed significant improvement in verbal memory following rTMS. There were no changes in [11C]raclopride binding in the caudate nucleus and putamen after rTMS treatment. LIMITATIONS: Our sample size was limited, and our study was an open trial lacking sham-treated controls. CONCLUSION: This study suggests that rTMS may be effective for the treatment of depression and also may improve verbal memory function. We observed no changes in [11C]raclopride binding, suggesting that there was no measurable increase in the release of dopamine at the second PET scan. Several animal studies and healthy human studies have indicated that dopamine can be released soon after acute rTMS. Our results suggest that release of striatal dopamine induced by rTMS may be only transient, or that dopamine release may be attenuated following chronic rTMS.

Adult↗

PubMed2004

A questionnaire survey of ECT practice in university hospitals and national hospitals in Japan.

Although electroconvulsive therapy (ECT) is being performed in many hospitals in Japan, there is little information on its present practice. We surveyed ECT practice to improve the practice of ECT in Japan. A mail questionnaire survey of ECT practice was conducted between 1997 and 1999 in Japan. Of 84 university hospitals and 37 national hospitals, 86 respondents (71%) were obtained. ECT was performed in 56 hospitals (65%). Details of ECT practice were further surveyed in 46 hospitals. The number of patients per year receiving ECT varied according to hospitals from 0.5 to 120. Unmodified ECT was still used in two thirds of the hospitals. Modified ECT was mainly performed in an operating room. Unilateral ECT was seldom used. Japan is an under-developed country for ECT and the practice of ECT must be improved.

Depressive Disorder↗

PubMed2004

[Electroconvulsive therapy: past, present, and future].

Although electroconvulsive therapy (ECT) was first introduced to treat schizophrenia in 1938, it is widely used for the treatment of various major psychiatric disorders, including depression. In western countries, its safety has been improved with the introduction of techniques such as succinylcholine muscle relaxation, barbiturate anesthesia, oxygenation and brief-pulse stimulation. Although the first use of ECT in Japan was reported in 1939, few modifications of the ECT technique have been made since then. From the 1980s, in collaboration with anesthesiologists, ECT with anesthesia and muscle relaxation (modified ECT) has been administered in numerous general hospitals. Moreover, brief-pulse ECT devices were approved in 2002. Rapid progress in ECT practices is expected in Japan. Before administering ECT, informed consent should be obtained from the patient, except when the patient lacks capacity to consent. The major problems in ECT are cognitive side effects and high relapse rates. Furthermore, its mechanisms of action are still unknown. These problems must be solved in the near future.

Electroconvulsive Therapy↗

PubMed2003

Neural mechanism of propofol anesthesia in severe depression: a positron emission tomographic study.

BACKGROUND: The precise neural mechanisms of propofol anesthesia in humans are still unknown. The authors examined the acute effects of propofol on regional cerebral blood flow (rCBF) using positron emission tomography in patients with severe depression. METHODS: In six severely depressed patients (mean age, 55.0 yr) scheduled for electroconvulsive therapy, anesthetic levels were monitored by electroencephalography, and rCBF was serially quantified in the awake, sedated, and anesthetized states. The authors used high-resolution positron emission tomography with 15O-labeled water and statistical parametric mapping 99 for imaging and analysis of the data. RESULTS: Global cerebral blood flow showed sharp decreases from the awake level during the administration of propofol, decreasing 26.8% in the sedated state and 54.4% in the anesthetized state. Moreover, a dose effect was seen in both parietal cortices and the left lateral prefrontal region with larger regions of relative decrease in rCBF at higher propofol doses. At the higher dose, the values of rCBF in the pulvinar nucleus of the thalamus, the pontine tegmentum, and the cerebellar cortex were also affected. Meanwhile, there were few changes of relative rCBF in the basal frontal lobes during both sedated and anesthetized states. CONCLUSIONS: As in earlier studies using normal subjects, pronounced suppression in rCBF in the brain stem reticular formation, the thalamus, and the parietal association cortex occurred even in severely depressed patients. However, previously reported decreases in rCBF in the basal frontal lobe were absent in depressed patients.

Adult↗

PubMed2003

[Meige's syndrome].

Explore the source record for details and available documents.

Antipsychotic Agents↗

PubMed2003

[Treatment algorithms for mood disorders].

The authors summarized features of and controversies about psychopharmacotherapy algorithms, which constitute evidence-based medicine, and compared historical backgrounds of the treatment algorithms of several countries as well as the outline of those for bipolar depression. They pointed out the potential for every clinician to use the current algorithms, which are rather rough, in a way that reflects his or her individuality and in close interaction with patients.

Bipolar Disorder↗