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Biomedical subjects

N Moriyasu

Publications and source records attributed to N Moriyasu.

At least 19 recordsLinked to original sources
PubMed1979

[Pre-sacral epidermoid cyst communicating with spinal CSF cavity (author's transl)].

A 6-year-old girl was transfered to our hospital because of continuing pleocytosis, and detection of the squamous cells and cholesterin crystals in the CSF. Neurological examination on admission revealed no remarkable disorders, except for weakness of anal sphincter. X-ray examination of the spine showed a deformity of the sacral vertebra. Myelography revealed a pre-sacral cystic tumor, which was connected with spinal CSF cavity at cul-de-sac of the spinal canal by a narrow fistula. The tumor was totally removed and no meningitic sign appeared in postoperative course. Histological examination diagnosed it as a typical epidermoid tumor. Attention should be payed to the location, size, structure and clinical course in this particular case.

Child↗
PubMed1979

[Contingent negative variation in patients with severe closed head injury--its diagnostic value as a quantitative evaluating method for certain aspect of posttraumatic syndrome (author's transl)].

CNVs were studied in 48 subjects with closed head injury followed by posttraumatic amnesia over than 7 days. Electrical motor-threshold stimulation of the median nerve or subjectively painful stimulation of the fingertip was used for imperative stimulus. An amplitude of CNV and its enhancement by painful imperative stimulus were measured and compared with those obtained from 34 normal subjects. In subacute stage within 3 months after the head injury, correlation between CNV abnormalities and an existence of some noticeable psychiatric disorders was found. In many of the subjects with CNV abnormalities, diffuse slow wave activities were observed in the background EEG, so that it was supposed that CNV abnormalities in subacute stage might reflect diffuse cerebral dysfunction and decreased vigilance. Any statistically significant correlation of CNV abnormalities to an existence of psychiatric disabilities, low score in WAIS and background EEG patterns could not be found in chronic stage 12 months after head injury. However, suppressed CNV was observed in all of 4 subjects who presented generalized epileptic patterns in the background EEG. Many of the subjects with suppressed CNV also showed a small effect of painful imperative stimulus on its amplitude. Statistically significant correlation between CNV abnormalities and work capacity was found. From these findings, together with previous observations (Tsubokawa et al. 19,36,40,44)), it is concluded that the measurement of the CNV is inimitable examination to evaluate certain psychiatric disability which is apt to be overlooked but, in fact, concerned intimately to the work capacity.

Adolescent↗
PubMed1978

Motivational slow negative potential shift (CNV) related to thalamotomy.

The alteration of cortical electrical activity induced by imperative stimulation following warning stimulation, contigent negative variation (CNV), and psychological changes following thalamotomy for relief of intractable pain (CM) and tremor (VL) are studied, since CNV has a close relationship with the degree of psychological activity. Ventrolateral thalamotomy does not have any effect on the amplitude of cortical CNV, but the ventromedioposterior part of the centre median has a generating action of CNV in itself and it has facilitatory effects upon cortical CNV. According to these results, the effective mechanism of centre median thalamotomy for relief of intractable pain is caused by suppression of attention and expectancy for exogenous stimuli following lesions of the centre median.

Contingent Negative Variation↗
PubMed1978

[Nerve fibers and nerve endings in the choroid plexus--electron microscopic study (author's transl)].

Nerve fibers and nerve endings in the fourth ventricle choroid plexus of the adult rat were studies with the electron microscope. Nerve endings were found at two sites within the plexus : 1) on the vascular wall (i. e., vascular nerve endings), and 2) in the stroma between the choroidal epithelium and the fibrovascular core (i. e., stromal nerve endings). Ultrastructurally all fibers were of the efferent type, and the majority were unmyelinated. No ganglion cell bodies were identified. Fibers ending in relation to the smooth muscle of the vessels presumably control the calibre of these vascular channels. Although the role of the stromal nerve endings is as yet unknown, these fibers may influence epithelial cell functions and thus indirectly regulate choroidal cerebrospinal fluid production.

Animals↗
PubMed1978

[Three cases of the dermoid and epidermoid tumors in the 4th ventricle (author's transl)].

Two cases with epidermoid and one case with dermoid in the 4th ventricle were treated in our clinic during the last one year. The clinical findings in these three cases were described, and dermoid and epidermoid tumors in the 4th ventricle were discussed dealing with the incidence and the characteristic features of the findings in CT scanning. The correct diagnosis of both epidermoid and dermoid in the 4th ventricle was done by CT-scanning which showed an irregular low density area of EMI No. -4 approximately 12 in the posterior fossa without any contrast media enhancement. The low density lesion could be differentiated by both angiogram and ventriculogram from arachnoid cyst, ependymoma, cystic astrocytoma and cystic hemangioblastoma in the 4th ventricle. Total removal of the tumor was performed on 2 cases, and a part of the tumor capsule attached to the medulla oblongata was left in the other case. All patients returned to their own job after operation.

Adult↗
PubMed1978

[A case of giant aneurysm at the posterior cerebral artery (author's transl)].

Giant aneurysm of the posterior cerebral artery was very rare. The authors could seek only 6 cases in published literature. We experienced one case of the giant aneurysm at the posterior cerebral artery. The case was 25 years old female. She occasionaly complained of headache and nausea for 4 years before administration. Cerebral angiogram revealed a giant aneurysm of the right posterior cerebral artery with slightly dilated ventricle. CT scan revealed a ring shape high density area and its high density area enhanced by Conray infusion. A clipping of posterior cerebral artery at the just proximal point of the aneurysmal neck was done, because adhesion of the aneurysm to the brain stem was very tight and the aneurysmal neck was very broad. After the operation, giant aneurysm was not seen on both angiogram and CT scan. Patient did not complain of headache any more and any defect of the visual field.

Adult↗
PubMed1977

[Modulating mechanism of the dorsal column stimulation for pain relief (author's transl)].

The neural mechanism of the modulating effects of spinal cord stimulation upon intractable pain was studied in cats under local anaesthesia. The electrical activity at the centre median nucleus of the thalamus (CEM), which responded to noxious stimuli and was inhibited by nitrous oxide inhalation, was recorded as an indicator of the degree of pain sensation. The suppressed effect upon the evoked potential responding to sciatic stimulation (1 Hz) was recorded during and after train stimulation of various parts of the spinal cord by means of silver ball bipolar electrode. Whenever inhibitory modulating effect upon CEM response was observed by spinal cord stimulation, the bilateral dorsal tractotomy cranial, caudal or both to the stimulating point in order to examine the influence upon the CEM potential. The results are as follows: 1) The CEM evoked potential responding to sciatic stimulation is inhibited by about 30-45% of its amplitude by dorsal column stimulation. This effect corresponds to the inhibitory effect by 75% N2O gas inhalation. Upon dorsal column stimulation, the intraspinal electrical activity is found in the central gray matter the antero-lateral quandrants of the spinal cord as well as the dorsal column. 2) Following lateral or anterior column stimulation as well as dorsal column stimulation, the CEM evoked potential responding to sciatic stimulation is inhibited by about 50% of its amplitude. 3) Following bilateral dorsal tractotomy cranial, caudal or both to the stimulating point, the CEM evoked potentials responding to sciatic stimulation are inhibited by dorsal column stimulation. According to the experimental results, it may be concluded that the inhibitory modulating mechanism by dorsal column stimulation for pain relief is not only mediated through the dorsal column, but also through other ascending spinal pathways.

Animals↗