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Biomedical subjects

M Tayama

Publications and source records attributed to M Tayama.

72 records · Page 4Linked to original sources
PubMed1984

A case of lissencephaly (agyria) syndrome with apnea--polygraphic study.

A 4-month-old infant with lissencephaly syndrome who was diagnosed on the basis of clinical symptoms and computed tomography experienced four apnea attacks during three polysomnographies. Apnea attacks were of two types. Type I apnea attacks were thought to be sleep apnea. The cause is unknown. Apnea was followed by tonic seizures due to hypoxia. Type II apnea attacks were thought to be epileptic apneic attacks, because they proceeded from the epileptic discharges in the right anterior temporal region (lead of electrooculogram). The origin of Type II apnea attacks was focused in the limbic system.

Apnea↗
PubMed1983

Postural effects on behavioral states of newborn infants--a sleep polygraphic study.

Physiological and behavioral correlates of neonates in the supine and prone positions were examined. Polygrams were recorded in 10 newborn infants in the prone and supine positions. Newborn infants slept more in the prone position than in the supine, and quiet sleep was significantly more in the prone position. Gross movement, jerky movement and twitch movement were less in the prone than the supine position. There was no difference in localized movement or tremor-like movement in the two positions. Respiration was more regular in the prone than the supine position. Sleep apnea (greater than or equal to 6 seconds) was less in the prone position. The pulse rate during quiet sleep was higher in the prone position.

Arousal↗
PubMed1983

Short latency somatosensory evoked potential in children.

The short latency somatosensory evoked potential was studied in 90 normal children of 1 month to 16 years old and 7 adults. Somatosensory stimuli were delivered through a disc electrode placed over the median nerve at the wrist joint. The uniform recording sites used were the central region of the scalp, and the seventh cervical spine or Erb's point. Reference electrodes were placed on the hand contralateral to the median nerve stimulated. Three positive peaks (P1, P2 and P3) and one negative peak (N1) were consistently recorded, a further positive peak (P4) after N1 was not always observed. The latency of each peak per 1 m body length decreased with age until 2 or 5 years of age. The latency of each peak after 2 years of age was positively correlated with the body length and arm length. The value of P1 peak latency per 1 m body length reaches adult values at an earlier rate than the value of P3 peak latency and P2-P3 latency per 1 m body length. This suggests that central lemmiscal pathways mature at a slower rate than peripheral nerve fibers. The wave form pattern of the short latency somatosensory evoked potential changed to the adult pattern at 10 years of age. The peak latency of P4 during deep sleep was slightly prolonged. In recording on infants during sleep, the EEG should be monitored to determine the stage of sleep.

Adolescent↗
PubMed1981

Influence of ACTH therapy on overnight sleep polygrams in infantile spasms.

Overnight sleep polygrams were recorded before and during therapy in nine patients with infantile spasms. Results showed that ACTH therapy increased the waking time and decreased rapid eye movement sleep. Thus it caused sleep disturbance in patients with infantile spasms. During ACTH therapy the number of rapid eye movements/min and the pulse rate decreased significantly. Body movements/min also decreased, but not significantly. These results suggest that ACTH therapy may inhibit functions of the central nervous system. The respiratory rate increased during ACTH and clonazepam therapy, probably in association with the decrease or the absence of seizures. These findings indicate the necessity for further studies on whether ACTH therapy is really of value in patients with infantile spasms, and show that if ACTH is given, the period of therapy should be as short as possible.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Biological rhythms in patients with lissencephaly (agyria-pachygyria).

Lissencephaly is a congenital malformation of the brain characterized by an extensive absence of cerebral gyral formation. Polysomnograms were recorded in 8 cases with lissencephaly (4 of agyria and 4 of pachygyria), and 24-h secretion of growth hormone, prolactin, luteinizing hormone, follicle-stimulating hormone and cortisol was examined in 6 of the 8 cases. The sleep-waking cycle and body temperature (BT) rhythm were studied in all 8 cases. The results were as follows: (i) the sleep-waking circadian rhythm was well preserved in 6 of the 8 cases; (ii) %REM (rapid eye movement) sleep decreased in 4 cases, but the ultradian rhythm of REM sleep was well observed in all cases except one; (iii) the secretion of GH and PRL showed normal or borderline increases with sleep; (iv) although these cases had not reached puberty, LH and FSH increased with sleep in 3 of 5 cases; (v) the circadian rhythm of cortisol secretion was preserved in all cases except one; (vi) BT showed a circadian rhythm after infancy. These findings suggest that the circadian rhythms function normally in lissencephaly, that the secretion of GH and PRL during sleep occurs almost normally, and that the cerebral cortex does not play a significant role in the regulation of these biological rhythms in lissencephaly.

Birth Weight↗
PubMedDate not supplied

Neuroimaging study of myotonic dystrophy. I. Magnetic resonance imaging of the brain.

Magnetic resonance imaging scans of the brain were obtained in 13 patients with myotonic dystrophy, seven with congenital myotonic dystrophy and six with adult-type myotonic dystrophy. All seven patients with congenital myotonic dystrophy had ventriculomegaly and a low IQ (DQ). Cerebral white matter lesions were observed in six cases, a small corpus callosum in four cases, a small brainstem in two cases, and a cerebellar white matter lesion in one case. Cerebral white matter lesions were observed in five of the six cases with adult-type myotonic dystrophy of which one had ventriculomegaly. The IQ (DQ) was significantly lower in patients with congenital myotonic dystrophy than in those with adult-type myotonic dystrophy. The incidence of a small corpus callosum or ventricular enlargement was higher in congenital myotonic dystrophy than in adult-type myotonic dystrophy. These findings may be related to the presence of neurologic impairment in congenital myotonic dystrophy.

Adult↗
PubMedDate not supplied

Neuroimaging study of myotonic dystrophy. II. MRI measurements of the brain.

The brain of patients with adult type myotonic dystrophy was measured using MRI, and compared with age- and sex-matched controls. The width of the cerebrum, and the areas of the corpus callosum, pons and pituitary gland were significantly smaller in adult-type myotonic dystrophy than in the controls. The IQ of the patients with adult-type myotonic dystrophy was lower than that of controls. These results demonstrate a decreased volume of the brain and pituitary glands in myotonic dystrophy. These findings suggest a causal relationship for the mental retardation and endocrine dysfunction that may occur.

Adult↗
PubMedDate not supplied

Serial EEG and sleep polygraphic studies on lissencephaly (agyria-pachygyria).

We carried out serial EEG studies on 12 cases of lissencephaly (6 of agyria and 6 of pachygyria), polysomnograms being recorded in 8 of the 12 cases. Fourteen Hz sleep spindles appeared from early infancy in all cases. They were poorly observed after the age of 1 year, and 5-11 Hz high-amplitude rhythmic activity (HARA) of more than 300 microV appeared predominantly in place of the 14 Hz spindles. Both the 14 Hz spindles and HARA showed asymmetry, but the dominant cerebral area for both types of waves was much the same. Four of the 6 agyria cases showed hypsarrhythmia within the first 6 months after birth, 3 of the 4 cases showing asymmetric hypsarrhythmia at first. Their hypsarrhythmia consisted of very high-voltage 5-7 Hz slow sharp waves and delta waves. The EEG abnormalities transformed from hypsarrhythmia to focal spikes in the 6 pachygyria cases. The polygraphic study on 8 cases revealed that the proportion of REM sleep decreased in 3 cases and the REMs/min values decreased in 7. Infantile spasms occurred in 4 of the 8 cases. The REM/min values decreased in all of these 4 cases, and, furthermore, the proportion of REM sleep decreased in 3 of the 4 cases. These findings suggest that lissencephaly involves a disorder of the brainstem, and that the combination of brainstem lesions and severe cerebral dysplasia is important for the manifestation of infantile spasms in lissencephaly.

Aging↗
PubMedDate not supplied

Proton magnetic resonance spectroscopy on childhood-onset dentatorubral-pallidoluysian atrophy (DRPLA).

To evaluate brain dysfunction of childhood-onset dentatorubral-pallidoluysian atrophy (DRPLA), three children with progressive myoclonus epilepsy, who were diagnosed as having DRPLA by DNA analysis, for the first time, underwent a study of proton magnetic resonance spectroscopy (1H-MRS). 1H-MRS obtained from both the parietal and basal ganglia regions disclosed markedly reduced ratios of N-acetylaspartate to both choline and creatine. Especially regarding the basal ganglia region, the latter (ratio of N-acetylaspartate to creatine) closely correlated to severity of genetic abnormality, i.e. number of expanded CAG repeats, suggesting that the degree of neuronal loss in the region strongly depends on genetic factors. 1H-MRS must be a valuable tool to clarify the pathophysiology of DRPLA.

Adolescent↗
PubMedDate not supplied

Characteristic evoked potentials in childhood-onset dentatorubral-pallidoluysian atrophy.

To determine the characteristics of multimodal evoked potentials (MEPs) in childhood-onset dentatorubral-palli-doluysian atrophy (DRPLA) we studied three DRPLA patients with progressive myoclonus epilepsy. Brainstem auditory evoked potentials showed reduced or absent brainstem components as well as delayed latencies. In addition, short latency somatosensory evoked potentials (S-SEPs) had prolonged central conduction time and reduced amplitude of cortical components. Two patients with symptom onset in the first decade of life had extremely enlarged flash visual evoked potentials with shortened latency even in the absence of giant SEPs. Therefore, children with progressive myoclonus epilepsy and the above MEP findings are likely candidates for childhood-onset DRPLA and should undergo DNA analysis for DRPLA.

Adolescent↗
PubMedDate not supplied

Infantile spasms: localized cerebral lesions on SPECT.

Ten infantile spasms (IS) patients had single photon emission computed tomography (SPECT) with [99mTc]HMPAO, EEG, and magnetic resonance imaging (MRI) studies. SPECT showed localized cerebral hypoperfusion in 7 infants (4 unifocal; 3 multifocal) always involving the temporal regions either unilaterally or bilaterally. EEGs obtained in near time of the SPECT studies showed focal abnormalities in all 7 infants with hypoperfusion on SPECT, with complete correspondence of the abnormalities in 5. MRI showed localized cerebral lesions in only 3 of the 10 infants, all of whom had corresponding areas of hypoperfusion on SPECT. Our study indicates that localized cerebral abnormalities (especially of the temporal lobes) may often be associated with IS and that such patients may have localized cerebral hypoperfusion on SPECT even when the MRI is normal.

Brain↗