Masayoshi Terashima

Electrophysiologic Analysis of Antidepressant Drug Effects on the GABAA Receptor Complex Based upon Antagonist-Induced Encephalographic Power Spectrum Changes

To better understand antidepressant drug effects on the GABAA receptor complex (the GABAA receptor, chloride ionophore and benzodiazepine receptor), we investigated how antidepressants influenced power spectrum changes induced by pentylenetetrazol (PTZ), a chloride ionophore antagonist, in the rat hippocampal electroencephalogram (EEG). In control recording, PTZ (27.5 mg/kg i.p.) increased EEG power at frequencies under 12 Hz up to five times. After rats were pretreated with imipramine, fluoxetine or trazodone for 7 days (10 mg/kg i.p., twice a day), PTZ could not increase EEG power to more than three times the power before injection; this effect was not observed after pretreatment for 3 days. These three antidepressants inhibit serotonin uptake, while two other antidepressants, desipramine and nortriptyline, that inhibit norepinephrine uptake failed to counter the PTZ effect. We concluded that antidepressants with serotonergic effects enhanced the function of the GABAA receptor complex.

Evaluating mental fatigue in patients with obstructive sleep apnea syndrome by the Maastricht Questionnaire

Abstract Mental fatigue in patients with obstructive sleep apnea syndrome (OSAS) was investigated and compared with subjects without OSAS. The study series comprised 189 habitual snoring patients and 75 controls. To measure subjective mental fatigue and somnolence, subjects were asked to complete the Maastricht Questionnaire (MQ) and the Epworth Sleepiness Scale (ESS), respectively, and patients also underwent diagnostic polysomnography. According to the apnea and hypopnea index, patients were classified into the following groups: primary snorers, or having mild, moderate, or severe OSAS. The lowest MQ and highest ESS scores were found in those patients with severe OSAS. It is proposed that the lowest MQ score is due to mental fatigue impairing awareness in patients with severe OSAS, probably because of attention loss.

Rapid eye movement‐localized apnea in a female patient with chronic insomnia

A middle‐aged female patient with chronic insomnia showed rapid eye movement (REM)‐ localized obstructive sleep apnea. She visited the Sleep Disorders Clinic and complained of insomnia with loud snoring. Once, in the past, her sleep complaints had disappeared after weight reduction but, 6 months later, she complained of excessive daytime sleepiness. Overnight polysomnography revealed REM‐localized apnea. Careful follow up is strongly recommended for a female patient with chronic insomnia who shows REM‐localized apnea.

An Electroencephalographic Study on a Family of Myoclonus Epilepsy

A family afflicted with myoclonus epilepsy was reported. Fig. 1 shows the family tree. Eleven members were affected and five died in infancy. EEG was performed on eight of the 11 patients. They were clinically classified into three types as follows. Type I : Mental deterioration appeared in childhood while generalized convulsion, myoclonus and ataxia progressively developed later. EEG showed a generalized excess of theta activity with poly-spikes and spike and wave complexes. These paroxysms could be precipitated by a photic stimulation in two cases. Type 11: Dementia gradually appeared in adulthood. Thereafter generalized convulsion, involuntary movements and ataxia developed. One case of EEG showed a slow background activity with spike and wave complexes. Poly-spikes were provoked by the photic stimulation. Dementia was not severe and gradually developed. Convulsion didn’t appear. EEG showed only a slight buildup by hyperventilation. Type 111: