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Biomedical subjects

M Tsuyumu

Publications and source records attributed to M Tsuyumu.

At least 19 recordsLinked to original sources
PubMed1997

[Arachnoid cyst of the middle cranial fossa with extraocular muscle paresis: case report].

Arachnoid cysts in the middle cranial fossa usually present with skull deformity, intracranial hypertension, epilepsy, focal symptoms and delayed mental development. Some cases, however, have neither symptoms nor signs. We have encountered a patient with an arachnoid cyst of the middle cranial fossa with extraocular muscle paresis and who was treated with cyst wall fenestration with good results. An 11-year-old boy presenting with double vision was diagnosed as having an arachnoid cyst in the middle cranial fossa with extraocular muscle paresis. He had no signs of increased intracranial pressure. This patient underwent a cyst membranectomy. Postoperatively this symptom rapidly subsided. Double vision disappeared two months postoperatively. To our knowledge, if those cases associated with increased intracranial pressure signs are excluded, this is the first case reported so far of a middle cranial fossa arachnoid cyst with extraocular muscle paresis. This report illustrates that extraocular muscle paresis can be caused by an arachnoid cyst in the middle cranial fossa and that knowledge of this could be helpful in its early diagnosis and treatment.

Arachnoid Cysts↗
PubMed1991

Painful tic convulsif: case report.

A case with painful tic convulsif is presented. A 77-year-old woman had developed trigeminal neuralgia 12 years before admission and ipsilateral facial spasm 2 years before admission. Upon operation, the superior cerebellar artery was found to impinge upon the entry zone of the fifth nerve. In addition, the anterior inferior and posterior inferior cerebellar arteries were found to bend along the seventh nerve. Teflon sheets were placed between the nerves and offending arteries. She has been pain-free and spasm-free for the past 18 months. Pathomechanism of the association of the multiple compression syndromes and the treatment are discussed.

Aged↗
PubMed1989

[Perifocal abnormal signal intensity area in MRI in meningiomas].

To investigate the perifocal abnormal signal intensity area in MRI in meningiomas, we have analysed MRI in 10 cases among 73 meningiomas which were diagnosed by X-ray CT and verified by operation and pathology. The MRI scanners used in this study were Siemens Magnetom and Toshiba MRT 15A. Ten meningiomas diagnosed by MRI were as follows; one free convexity, one pyramidal, three falx and parasagittal, one sphenoid ridge, one olfactory groove, one cerebellopontine angle, two ventricular meningiomas. Perifocal abnormal signal intensity area was diagnosed as vasogenic edema in 4 cases. This area was shown as high signal intensity in T2-weighted MRI and was confined to the white matter. In proton density-weighted MRI, it was shown as high signal intensity and usually clearly distinguished from rather iso- or hypointensity tumor area. In T1-weighted MRI, this area was shown as slightly low signal intensity, which could be readily differentiated from the remarkably low intensity ventricular CSF. In one case a thin semi-lunar abnormal intensity area bordering the tumor was verified in MRI, but no abnormal area was shown in CT. In the remaining 6 cases, namely one free convexity, one pyramidal and two ventricular meningiomas, one cerebello-pontine and one sphenoid ridge meningioma, in which CSF abutted the tumor, abnormal signal intensity area was diagnosed as entrapped CSF space. The perifocal abnormal signal intensity area in MRI should be regarded as vasogenic edema or entrapped CSF space, and these two should be differentiated by the signal intensity, the distribution of the area and CT-cisternography.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

[Experimental study of single and combined coaxial exposure by high-peaked pulse wave CO2 and Nd:YAG laser on the brain: effect on the brain microvasculature in the subacute stage].

The effect of single or combined coaxial exposure by Nd: YAG and CO2 (pulse wave) laser on the brain at the subacute stage was examined in experimental animals. Soft X-ray microangiography and histological examination of the brain were performed 48 hours after laser exposure. The lasers in this study were pulse wave form CO2 of 2, 4 and 8 watts and YAG lasers of 10, 20 and 40 watts, employed separately or simultaneously using 130 YZ of Nihon Infrared Industries Company. Japanese white rabbits were anesthetized with pentobarbital. Bilateral fronto-parietal craniectomy were made, and the dura was removed. After intravenous injection of Evans blue, the lasers were employed to the cerebral cortex using a micromanipulator attached to the operation microscope. The spot size was 0.7 mm in diameter for CO2 laser and 1.2 mm for Nd: YAG laser. Forty-eight hours after exposure, microangiography was performed and brains were prepared for the histological examination. Histological examination and microangiogram of the brain after CO2 laser exposure revealed semilunar avascular area in the edematous layer surrounded with dilated vessels. Histological examination and microangiogram of the brain after Nd: YAG laser exposure revealed broad avascular or oligovascular zones in the surrounding edematous tissue, in which the surviving vessels were narrowed. Edematous zones were also shown in the subcortical portion. The histological examination and microangiogram after combined coaxial exposure of CO2 and Nd: YAG lasers revealed triangular avascular or oligovascular zones in the edematous tissue, in which the surviving vessels were narrowed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Effects of Nd:YAG and CO2 lasers on cerebral microvasculature. Study in normal rabbit brain.

The effect of Nd:YAG and CO2 laser beams on cerebral microvasculature was examined in experimental animals. Soft x-ray microangiography and histological examination of the brain after Nd:YAG laser exposure revealed broad avascular or oligovascular zones in the irradiated and the surrounding edematous tissue, in which the surviving vessels were narrowed and tapered without significant leakage of blood. After CO2 laser exposure, a wedge-shaped tissue defect surrounded by layers of charring, coagulation, and edema was observed. The main finding in the surrounding coagulation and edematous layers was dilatation of the vessels. Hemorrhage was sometimes observed, mainly in the edematous layer. These findings seem to explain the effective hemostatic capability of the Nd:YAG laser and the occasional hemorrhage following CO2 laser exposure, especially at high energy output.

Animals↗
PubMed1986

[A mechanism of development and resolution of vasogenic brain edema].

To investigate the mechanism of development and resolution of vasogenic brain edema, authors have infused the mock CSF containing 35S-sodium thio-sulfate via a thin needle into the white matter of either normal cat's brain or into the edematous brain. The animals which were used in these experiments were divided into four groups (L20, L45, C20, C45). In the groups of animals subjected to a cold lesion (L20, L45), a small craniotomy was performed over the right frontal pole. A cold injury edema was produced 24 hours prior to the experiment. Na-Fluorescein (2 ml/kg) was given intravenously just prior to the cold lesion to later visualize the extent of the edema. For the positioning of the four needles in the brain, the coordinates were used according to the Horsley-Clark method and the atlas of Reinoso-Suarez. The location of tissue infusion (TIP) corresponds to a point approximately 3.0 mm before the frontal apex of the right lateral ventricle. The infused artificial CSF was mixed with 35S sodium-thiosulfate and stained with Evans Blue to check the extent of propagation of the infused solution. This solution was infused into the tissue at the point TIP with a rate of 0.20 ml/hr in groups C20 and L20 and 0.45 ml/hr in groups C45 and L45. Both lateral ventricles and cisterna magna were cannulated, and a ventriculo-cisternal perfusion with an artificial CSF was established through the right lateral ventricle with a perfusor. The perfusion rate was 2.25 ml/hr. The cisternal outflow was collected during every 15 min. for the activity and volume measurement. Tissue water content was determined by the drying method.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

[Hydrocephalus in Paget's disease--a case report].

A case of Paget's disease in an elderly female who had a favourable evolution following ventriculoperitoneal (V-P) shunt is reported. On May 28, 1983, a 52-year-old female was transferred and admitted to us from the Dept. of Neurology because of headache in the occipital region and ataxic gait. On admission, neurological examinations revealed remarkably increased tendon reflexes, ataxic gait, and mild dementia. Headache was also observed, but urinary incontinence was not present. Skull X-ray showed "cotton wool appearance", which was characteristic of Paget's disease. On chemical analysis of blood and urine, serum Al-P and urinary OH-proline level were elevated, which established a diagnosis of Paget's disease. Triventricular dilatation was found on CT scan, and neck tomography showed basilar impression. After admission, the patient was treated with calcitonin, but it was interrupted because of side effects such as nausea and vomiting. Then she gradually took a turn for the worse, particularly dementia became severer. On July 25, 1983, V-P shunt was performed. After operation, "soft landing maneuver" was employed, namely the intraventricular pressure was checked and was gradually lowered with external CSF drainage system for 7 days. Thereafter the patient's head was elevated gradually from supine to sitting position through 7 days. Her hospital course after operation was that of gradual improvement. The purpose of this maneuver was to prevent sudden change of intraventricular pressure that causes aggravation of basilar impression and sudden respiratory arrest.

Cerebrospinal Fluid Shunts↗
PubMed1985

[Experimental study of brain lesions after combined coaxial exposure to high-peaked pulse wave form CO2 and Nd: YAG lasers on the brain].

UNLABELLED: The CO2 laser is useful for cutting and vaporization but not for coagulation and hemostasis. On the contrary, YAG laser is effective for coagulation and hemostasis but not for cutting. The purpose of this study is to examine the effect of the exposure of combined, coaxial CO2 and YAG laser on the animal brain to supplement the advantages and draw-backs of each other. To compare these results, each of non-combined pulse wave form CO2 and YAG lasers was employed separately. MATERIALS AND METHODS: The lasers in this study were pulse wave form CO2 and YAG lasers, employed separately or simultaneously using 130 YZ of Nihon Infrared Industries Company. Japanese white rabbits were anesthetized with pentobarbital. Fronto-parietal burr holes were made, the dura was removed and then Evans blue solution was injected intravenously. The lasers were employed to the cerebral cortex without great vessels using a micromanipulator attached to the operative microscope with a distance of 30 cm. The spot size was 700 mu for CO2 laser and 1200 mu for YAG laser. The first experiment was to see the effect of nine combinations of simultaneous coaxial CO2 of 2, 4 and 8 watts and YAG lasers of 10, 20 and 40 watts, 1 sec on the brain. In the second experiment, also combining two lasers, the exposure time of YAG laser was elongated from 1 or 2 seconds into 2 or 4 seconds and the arrangement of powers was the same as that of the first experiment. The lesions were thus made in 18 different conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1981

Dynamics of formation and resolution of vasogenic brain oedema. I. Measurement of oedema clearance into ventricular CSF.

Previous studies showed that resolution of brain oedema may occur by clearance into the CSF. The present study was performed to measure quantitatively the amount of oedema clearance in cold-induced oedema in cats. In order to determine the minute amounts of oedema fluid entering the CSF the oedema fluid was labelled with a high concentration of an extracellular marker (S35-sodium-thiosulphate). Ventriculo-cisternal perfusion was used to collect the marker in the cisternal outflow. By using the assumption that oedema fluid has the same marker concentration as the plasma, the distribution profile of extracellular space as well as the clearance rate of oedema into CSF could be computed. Oedema and thiosulphate space were most pronounced in the white matter underlying the cortical cold injury. The values then declined progressively with the distance from the lesion towards the ventricle. Oedema fluid clearance into the ventricular CSF at 24 hours following the cold injury amounted to 0.8-1.2 microliter/min or 1.15 ml/day. These data support the assumption that this may be one of the main mechanisms of the resolution of vasogenic brain oedema.

Animals↗
PubMed1979

Modification of periventricular hypodensity in hydrocephalus with ventricular reflux in metrizamide CT cisternography.

An analysis of metrizamide computed tomography (CT) cisternographic findings in cases of communicating hydrocephalus has been carried out. Serial observations of the density in the periventricular area in 19 cases with metrizamide ventricular reflux have revealed the following different patterns: (a) precontrast periventricular hypodensity diminishing after CT cisternography and possibly indicating transependymal metrizamide migration (two cases); (b) periventricular hypodensity unchanged (two cases); (c) minimal periventricular hypodensity with slight rise in its attenuation values after ventricular metrizamide reflux (four cases); and (d) no periventricular hypodensity and no change after reflux (six cases). Our preliminary experience indicates that the presence of periventricular hypodensity with an increase in its attenuation values following ventricular reflux of metrizamide is possibly a criterion that may be used in favor of a cerebrospinal fluid shunting operation.

Adult↗
PubMed1979

[Metrizamide CT cisternography in skull base tumors (author's transl)].

Twenty-three cases suspected of skull base tumors were examined by CT cisternography (CTC) with CT scanner (EMI 1010) from April, 1977 to March, 1978. The lesions in 20 cases were diagnosed as positive and confirmed by operation and/or autopsies. These include five acoustic neurinomas, six pituitary adenomas, two craniopharyngiomas, two skull base meningiomas, one arachnoid cyst and miscellaneous tumors. Isotonic Metrizamide solution four of 2-10 ml was injected via lumbar route. Patients were kept in 30 degrees Trendelenburg position for 60 minutes until the first scanning. Scannings were obtained 1, 3, 6, 24 and in some cases 48 hours after lumbar injection. No side effects except for headache, nausea, vomiting occurred. There were no convulsions. In diagnosing cerebellopontine angle tumors, the indirect signs such as asymmetrical ambient cisterns are of importance, when combined with direct signs, i.e. a shadow defect. Parasellar tumors are usually difficult to diagnose with conventional CT due to streak artifact caused by adjacent bony structure. In CTC the extrasellar extension of pituitary tumors were clearly visible. The size, shape, dimensions and the relationship to the adjacent structures of the craniopharyngiomas were easily demonstrated with CTC especially when a coronal view was added. In arachnoid cyst, CTC demonstrated the delayed turnover of Metrizamide between the cyst cavity and the adjacent subarachnoid space. In conclusion, CTC is an useful neuroradiological diagnostic adjunct because of minimal bony streak artifact and high spatial resolution. It would be expected that small tumors of even 2-3 mm in diameter might be diagnosed, from the fact that the middle cerebral artery in the suprasellar cistern is clearly visible as a shadow defect.

Brain Neoplasms↗
PubMed1978

Diagnostic value of CT cisternography with intrathecal metrizamide enhancement, comparison with isotope cisternography.

Metrizamide CT cisternography (CTC) was performed for the evaluation of CSF dynamics and the diagnosis of skull-base tumors. Results of CTC in 52 cases examined for the study of CSF dynamics correlated well with those of isotope cisternography. However, the degree and duration of ventricular stasis of metrizamide and its transition into a periventricular low-density area in hydrocephalus were recognized more accurately in CTC. Twenty out of 23 cases with suspected skull-base tumor were diagnosed as positive and confirmed by operation. CTC was especially useful in parasellar, CP angle, and other posterior fossa tumors.

Brain Neoplasms↗
PubMed1978

Sequential delayed enhanced CT in brain tumors.

Delayed enhanced CT was performed in 53 cases and these findings are compared with those of delayed radioisotope scan and with operative and histopathologic findings. We have classified the results of enhancement into four types as follows: (1) immediate enhancement pattern due to rich vascular bed, typical in meningiomas; (2) delayed enhancement pattern due to exudation, often seen in cystic astrocytomas; (3) intermediate sustained pattern due to both mechanisms in glioblastoma multiforme; (4) no enhancement pattern as in diffuse astrocytomas. The results of delayed enhanced CT correlated well with those of radioisotope scan.

Brain Neoplasms↗