Biomedical subjects
Publications and source records attributed to J Kohyama.
A female infant with seizures refractory to conventional therapeutic agents was presented. Mexiletine hydrochloride, administered orally, was effective in controlling her seizures. Her sleep structure and psychomotor development seemed to improve after reduction of the fits.
An 11-month-old girl suffering from Dandy-Walker malformation (DWM) associated with tetralogy of Fallot (TOF) is presented. There has been no report describing a case of DWM associated with TOF. Our case may raise a new discussion on the teratogenic period of these anomalies. A polysomnogram was obtained, and basic sleep components, such as the proportion of each sleep stage and the numbers of body movements and rapid eye movements, showed no significant differences from those in the controls, despite hydrocephalus, pachygyria of the cerebral cortex and a large low density area in the posterior fossa.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
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Polysomnograms were obtained for five severely brain damaged patients, and phasic sleep parameters-body movements (BMs) and rapid eye movements (REMs)-were examined. CT scanning of their brains demonstrated large low density areas in the bilateral hemispheres. In the three patients with flat EEG, sleep could only be classified into two stages; one with REMs[R(+)] and one without REMs[R(-)]. In the other two patients, stage R(-) was further classified into two stages according to the EEG findings. Gross movements (GMs) showed a synchronous pattern in all the patients. GMs and low angle REMs decreased in number while twitch movements and high angle REMs showed almost the same incidences as in normal controls. Localized movements showed marked variations among the patients. It was suggested that, except for normal uncoordinated asymmetrical GMs, BMs did not necessarily require higher brain structures for their generation.
A male infant was born to a mother who had been suffering from primary hyperaldosteronism with the administration of alpha-methyldopa (MD) during pregnancy. His behavioral development, especially that of sleep, was studied by means of sleep-awake rhythm and polysomnography recordings (PSG) from 2 months to 2 years and 5 months of age. His daily sleep-awake rhythm showed some abnormal pattern. As to the PSG, the proportion of each sleep stage was normal and the two types of body movements (BM) showed various patterns. A paradoxical increase was seen in the twitch movement of some muscles. MD affects the catecholamine system in the CNS and human sleep. Since the sleep-awake rhythm and BM are thought to be related to the monoaminergic system in the CNS, we assume that his behavior and sleep disorders are the effects of the maternal MD administration during pregnancy.
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A 10-year-old male patient, who had suffered from intractable convulsions from the neonatal period, is presented. Serial brain images suggested slow, gradual destruction of neural elements. Human cytomegalovirus (HCMV) DNA was detected in his cerebrospinal fluid (CSF) by means of the polymerase chain reaction. Intrathecal interferon had a favorable effect on his seizures. We assume a close relationship between HCMV and some chronic types of epileptic encephalitis/encephalopathy.
For the generation of phasic muscle activity during rapid eye movement (REM) sleep, strong motor excitation to overcome both tonic and phasic inhibition is needed at the motoneuron level. Descending pathways originating in the rostral pons (cholinoceptive (nucleus reticularis pontis oralis-->nucleus reticularis gigantocellularis, peri-locus coeruleus pars alpha-->nucleus reticularis magnocellularis) and cholinergic (pedunculopontine tegmental nucleus-->nucleus reticularis paramedianus) pathways) are involved in motor inhibition during REM sleep. Since the origins of excitatory drives related to phasic muscle activity during REM sleep are also in the brainstem, the occurrence of phasic muscle activity can be said to be determined by brainstem activity. We review the basic and clinical studies on phasic muscle activity during REM sleep and propose the possibility that it can be a beneficial parameter for assessing brainstem activity, especially in relation to its maturation during early stage of life.
Two brothers with the typical clinical features of oculocerebro-renal syndrome of Lowe exhibited delays in developmental milestones, muscular weakness and hypotonia, and high serum creatine kinase activity. The biopsied muscle revealed selective type 1 fiber atrophy and mild type 1 fiber predominance, similar to that observed in congenital fiber type disproportion myopathy. The abnormal fiber type distribution may be responsible for the common finding of muscle hypotonia in this syndrome.
Although brainstem immaturity has been postulated as one of the pathogenesis underlying cyanosis during feeding (CDF), there has been no widely accepted physiologic parameter that reflects brainstem function. We recently proposed that the dissociation index (DI), one of the phasic sleep parameters, is a reliable and quantitative sleep parameter for assessing brainstem maturation during early infancy. In the present study, we evaluated brainstem impairment in infants with CDF using phasic sleep components. Polysomnographies were obtained for 12 infants with CDF who were equally divided into 2 groups: one had or subsequently experienced apparent life-threatening events or sudden infant death syndrome (ALTE-SIDS group) and the other did not (CDF group). Rapid eye movement density and the number of gross movements (body movements, including the trunk, lasting greater than or equal to 2 sec) in the patients were identical to those in the controls. In the CDF group, the decrease of the average DI value from the controls was significantly less than the decrease in the ALTE-SIDS group. CDF may be a mild expression of brainstem immaturity. DI appears to be useful when evaluating infants with cyanosis during feeding.