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Biomedical subjects

I Murase

Publications and source records attributed to I Murase.

10 recordsLinked to original sources

Ruptured anterior communicating artery aneurysm encased in a tuberculum sellae meningioma. Case report.

This 70-year-old woman suffered a subarachnoid hemorrhage (SAH) from a ruptured anterior communicating artery aneurysm encased in a meningioma in the tuberculum sellae. Although preoperative magnetic resonance imaging disclosed that the aneurysmal complex was completely enclosed in the tumor, angiographic studies did not reveal arterial narrowing. The embedded aneurysm caused diffuse SAH rather than intratumoral hemorrhage. These factors indicated very little adhesion between the tumor and the encased arteries. Surgery was performed on the 20th day post-SAH. Intraoperative findings revealed that the tumor did not adhere to the enclosed vasculature except at the point of rupture of the aneurysm. The authors were able to clip the aneurysm safely after piecemeal removal of the tumor, which was finally extirpated without fear of aneurysm rupture. Careful stepwise procedures were essential to treat the aneurysm and the tumor simultaneously.

Aged↗

Central neurocytoma presenting with intratumoral hemorrhage 15 years after initial treatment by partial removal and irradiation.

A 50-year-old male presented with a central neurocytoma with intratumoral homorrhage. He had undergone partial removal of the tumor and postoperative radiation therapy 15 years previously. He was followed as an outpatient after the initial treatment, and there was no evidence of regrowth of the residual tumor. Removal of the hematoma and biopsy of the tumor were performed. Abnormally developed blood capillaries in the tumor may have undergone disturbances of circulation caused by irradiation which resulted in bleeding. Patients with partially resected central neurocytomas which have low proliferative potential may not require radiation therapy, due to the benign nature and the risk of delayed complications of irradiation including intratumoral hemorrhage.

Adult↗

[Practical localization of the central sulcus using a video display during surgery by cortical somatosensory evoked potentials and how to discern precentral P20 and central P25].

In patients with lesions around the central sulcus, cortical surface somatosensory evoked potentials (SEPs) have been applied for the purpose of localization of the central sulcus based on the polarity inversion of postcentral N20 to precentral P20 across the central sulcus. We have intraoperatively monitored SEPs to infer the location of the central sulcus in 16 cases since December 1988. Intraoperative localization of the central sulcus has been most useful in patients with frontal lobe gliomas in which the localization of the central sulcus enables the surgeon to extensively resect tumor without postoperative motor weakness. The localization of the central sulcus, however, might be misjudged by using the polarity inversion criterion alone, because central P25 following N20 and P20 complicates SEP waveforms. It is significant that P25, which is recorded also posterior to the central sulcus, is discerned from the precentral P20. In order to solve this matter, we regarded only the positivity in SEP waveforms having the identical peak latency to that of N20 as the precentral P20. Positive potentials having a later peak latency than that of N20 are the superposition of P20 and P25, and might also be recorded posterior to the central sulcus. For the observation of the polarity inversion of N20 to P20 across the central sulcus, a multi-channel SEP should be recorded using a sheet of silicone rubber embedded in a 16-electrode array consisting of a 4 by 4 grid. We projected the exposed cortical surface on the video display through the microscope apparatus and marked the locations of the recording electrodes on the video display. This enabled the location of the recording electrodes to correspond easily and precisely to the cortical surface. Our reliable and simple method of intraoperative localization of the central sulcus by cortical SEPs monitoring is presented in a practical case.

Adolescent↗

Primary spinal leptomeningeal gliomatosis presenting visual disturbance as the initial symptom: case report.

We report a case of diffuse leptomeningeal gliomatosis which spread from the cervical to the sacral spine. A 60-year-old man was admitted with visual disturbance due to papilledema. Magnetic resonance imaging revealed holocord leptomeningeal gliomatosis without a definite intraparenchymal lesion, and the patient's neurological examination was unremarkable except for papilledema. Intracranial hypertension secondary to spinal tumor is well known but unusual, and the mechanism is still unclear. In our case, an elevated protein concentration of cerebrospinal fluid is suggested as the cause of intracranial hypertension.

Brain↗

[Cooperative multicentric study on posttraumatic epilepsy].

A multicenter cooperative study was conducted to investigate factors influencing posttraumatic epilepsy (PTE) and to evaluate the prophylactic effect of anticonvulsants. A retrospective study of 102 PTE patients revealed the following typical clinical features: occurrence in young males, traffic accidents, contusion and/or cerebral hematoma. The latent period after the injury was longer in children. The percentage of EEG paroxysmal activity gradually increased as the generalized abnormality diminished. A retrospective-prospective study of 1998 patients who suffered a head injury between 1984 and 1988 was conducted till 1994. During the follow-up period, 62 patients (3.1%) developed PTE. The drop-out cases were excluded, and the 154 cases followed at least two years were analyzed. Statistical analysis of differences between patients with and without PTE suggested following factors: young, immediate early epilepsy (within 24 hours after injury; IMEE) and early epilepsy (within one week after injury). The risk with the highest relative risk rate was early epilepsy. Multiple regression analysis revealed that three factors, IMEE, early epilepsy and young age, contributed to the prediction of PTE. There was no significant difference in the percentage of patients having PTE in the group treated with anticonvulsants and the untreated group. Anticonvulsant treatment after head injury was unlikely to have a prophylactic effect on the development of PTE.

Adolescent↗

[A case of ossifying fibroma of the skull].

A 23-year-old woman was admitted to our hospital because of a soft, painful mass in the right parietal region for a month. Neurological examination revealed no abnormality. Laboratory data including serum Ca, P and alkaline phosphatase were normal. Skull x-ray film showed a partially osteolytic, not well circumscribed lesion in the right frontal, parietal and occipital bone. No remarkable sclerotic area was seen in the lesion. CT scan showed that the lesion was located in the diploë, destroying both inner and outer tables of the bone. Right external carotid angiogram revealed that the lesion is supplied by the branches of superficial temporal artery and middle meningeal artery. 99mTc bone scan showed increased uptake in the lesion. The patient underwent a right parietal craniectomy. The skull bone was invaded by the tumor, which was yellow-brown in color, thickened and fragile. We could easily perforate it through. The tumor didn't invade the dura mater or periosteum. It was extensively removed with an airtome and rongeurs. A cranioplasty was carried out using a plastic resin. The pathological specimen showed that the tumor was mainly composed of mature, regularly-aligned bone and intermingled fibrous tissue. Neither mitosis nor atypical cellular features was seen. These findings were compatible with the diagnosis of ossifying fibroma. The postoperative course was uneventful and the patient was discharged in a good condition. There was no evidence of local recurrence 10 months later. Ossifying fibroma is a rare, benign bone tumor that mainly involves the craniofacial bone. The differential diagnosis of ossifying fibroma versus fibrous dysplasia is difficult. These diseases can be differentiated on combined clinical, radiological and morphological grounds.

Adult↗