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Biomedical subjects

S H Okawara

Publications and source records attributed to S H Okawara.

At least 19 recordsLinked to original sources
PubMed1997

Repeat intra-arterial papaverine for recurrent cerebral vasospasm after subarachnoid haemorrhage.

We assessed the prevalence of recurrent vasospasm following failure of intra-arterial papaverine and the efficacy of repeat intra-arterial infusions of papaverine for control of recurrent vasospasm. Of 24 patients treated with intra-arterial papaverine for vasospasm following aneurysm surgery, 12 did not improve clinically after the initial treatment; 9 received second or third infusions on consecutive days; 6 received only a second infusion; and 3 received a third. Superselective infusion into the intracranial arteries was performed in all nine cases. Despite angiographic improvement after the initial or second infusions, all nine patients showed varying degrees of recurrent vasospasm at the time of the second or third treatment. Within 24 h of a second infusion, three of the six patients had significant clinical improvement, and one of these showed marked improvement soon after a third infusion. Our preliminary results suggest that repeat papaverine infusion may be a way of controlling recurrent or recalcitrant vasospasm.

Adult↗
PubMed1994

Acute cerebellar hemorrhage secondary to capillary telangiectasia in an infant. A case report.

We encountered an unusual case of an acute cerebellar hemorrhage secondary to a capillary telangiectasia in a 4-month-old infant. Prompt surgical evacuation of the cerebellar hematoma resulted in an excellent neurologic outcome. To the best of our knowledge, ours represents the only clinical case report of massive cerebellar bleed due to a capillary telangiectasia.

Acute Disease↗
PubMed1992

Acute subdural hematoma after aneurysmal rupture; evacuation with aneurysmal clipping after emergent infusion computed tomography: case report.

A 74-year-old woman sought treatment after an initial subarachnoid hemorrhage verified on computed tomographic scan with no focal neurological deficit. Shortly after admission, she sustained a second subarachnoid hemorrhage with acute neurological decompensation. A repeat computed tomographic scan revealed increased blood along the right medial temporal region, as well as in the interhemispheric fissure and bilateral sylvian cisterns. Also evident was a right hemispheric acute subdural hematoma. The patient's rapidly deteriorating neurological status precluded a cerebral angiogram; therefore, a double-dose infusion computed tomographic scan was performed. This revealed a cerebral artery aneurysm adjacent to the right medial temporal hematoma. She was taken to the operating room on the basis of this study. After evacuation of the right hemispheric subdural hematoma and clipping of the right posterior communicating artery aneurysm, the patient made a rapid, full neurological recovery.

Aged↗
PubMed1992

Ultrasonographic and electrophysiological adjuncts to surgery within the brain stem: technical note.

The surgical approach to intrinsic lesions within the brain stem is undertaken by the surgeon knowing the potential for significant operative morbidity. We report the use of real-time intraoperative ultrasound and electrophysiological mapping techniques to aid in the localization and resection of an intrinsic brain-stem tumor in a child. These techniques permitted an aggressive surgical approach without encountering adverse postoperative neurological sequelae.

Brain Mapping↗
PubMed1991

Lymphocytic hypophysitis with involvement of the cavernous sinus and hypothalamus.

Two cases of lymphocytic hypophysitis are reported, in which hypothalamic involvement causing diabetes insipidus was a prominent clinical feature. In one case, a man had clinical and radiological evidence of the involvement of the cavernous sinus. This represents the second reported case of a man with lymphocytic hypophysitis. A transsphenoidal biopsy established the diagnosis in both cases. Neither the involvement of the cavernous sinus nor permanent diabetes insipidus has been reported previously. A review of the literature is provided.

Adult↗
PubMed1988

Organization, fine structure, and viability of the human adrenal medulla: considerations for neural transplantation.

Recent reports of adrenal medullary autografts in patients with Parkinson's disease raise several important questions with respect to the cell types actually being transplanted as well as the potential for chromaffin cell banking prior to neural transplantation. In this study, we determined the general morphological characteristics of the human adrenal medulla and assessed factors important for the maintenance of cultured chromaffin cells for later use as transplants. The human adrenal medulla contained islands of cortical cells scattered throughout the gland as well as Schwann cells, nerve endings, endothelial cells, pericytes, isolated ganglionic neurons, and connective tissue elements such as fibroblasts and smooth muscle cells. Because many of these cell types are mitotically active, transplantation of medullary fragments that contain these cells could have far-reaching consequences. One approach that could circumvent the problems arising from multiple cell types in the medulla is differential plating of chromaffin cells prior to transplantation. Differential plating yielded relatively pure populations of chromaffin cells that demonstrated excellent viability if processed within 2 hours after cessation of the gland's circulation. Chromaffin cells cultured in the presence of nerve growth factor exhibited a neuronal phenotype, possessed catecholamine histofluorescence, and displayed tyrosine hydroxylase- and dopamine beta-hydroxylase-like immunoreactivity. The sex and age of the donor did not affect cell viability or morphological characteristics.

Adrenal Medulla↗
PubMed1988

Restoration of hearing after removal of cerebellopontine angle meningioma: diagnostic and therapeutic implications.

A case of cerebellopontine angle meningioma with restoration of hearing from a profoundly deaf state is presented. Meningiomas of the posterior fossa commonly present with decreased or absent hearing and can appear deceptively similar to acoustic neurinomas on radiographic and audiometric testing. Because total restoration of hearing can occur with meningioma, even with significant preoperative deficit, utilization of the translabyrinthine approach is less desirable if any preoperative question as to the diagnosis exists. Any hearing-impaired patient with a cerebellopontine angle mass that is not conclusively thought to represent acoustic neurinoma should be approached by the suboccipital technique to maximize the opportunity for restoration of hearing.

Adult↗
PubMed1986

Amitotic neuroblastoma cells used for neural implants in monkeys.

The potential utility of cultured neuroblastoma cells as donor tissue for neutral implants into the mammalian brain has been examined. Cells from a human neuroblastoma cell line, IMR-32, were labeled with [3H]thymidine and chemically rendered amitotic. These differentiated IMR-32 cells were grafted into the hippocampi of five adult African Green monkeys, and graft survival was evaluated for up to 270 days after transplantation. Autoradiographically labeled grafted cells were identified in four animals. Processes from grafted cells could be followed for distances of up to 150 micrometers into the host brain. No evidence for neoplastic growth of the transplant was found. Thus, grafted neuroblastoma cells can survive for prolonged periods in the primate brain and may serve as a practical source of donor tissue for neural implants.

Animals↗
PubMed1986

Pontomedullary infarction from sustained cervical spine hyperflexion.

A paraplegic but independent 26-year-old man developed pontomedullary infarction from a fall which placed him in a position of sustained cervical spine hyperflexion. An early noncontrast computed tomography scan displayed infarction of the pontomedullary region. The patient made partial recovery of his neurologic deficits. The infarct was thought to arise from compromise of blood flow through the vertebrobasilar vessels during hyperflexion of the cervical spine. The mechanisms that impeded blood flow in the vertebrobasilar territory and the prognostic factors of ischemic infarction in this area are discussed.

Adult↗
PubMed1984

Neurocutaneous melanosis with extensive intracerebral and spinal cord involvement. Report of two cases.

Two unusual cases of neurocutaneous melanosis are presented. Both patients had congenital giant hairy nevi and both developed hydrocephalus, seizures, and myelopathy. The first patient displayed multicentric cerebral and spinal cord melanosis, as opposed to the more commonly described basilar leptomeningeal involvement. The second patient had total spinal leptomeningeal involvement, and ventriculoperitoneal shunting for hydrocephalus produced peritoneal metastasis of melanoma. An individual born with a congenital giant hairy nevus or marked generalized cutaneous pigmentation should be closely observed for the development of malignant melanoma of the nervous system.

Adult↗
PubMed1975

Electrophysiologic analysis of aberrant regeneration after facial nerve paralysis.

The blink reflex, ordinarily elicited only in the orbicularis oculi and not in other facial muscles, can be used to detect synkinetic movements objectively. In 26 of 29 patients tested at least 4 months after facial nerve degeneration, an aberrant blink reflex was recorded in the orbicularis oris on the affected side. Of the remaining three, one had injury to only a peripheral branch of the facial nerve and experienced a return of function with no evidence of synkinesis; in the other two, the affected side of the face was totally paralyzed in the absence of facial nerve regeneration. Synkinetic movements ultimately will occur in nearly all cases following facial nerve degeneration provided that the facial nerve regenerates from a proximal site.

Adolescent↗