摘要:

Recent technical advances in interventional neuroradiology have made it possible to dilate cerebral arteries showing vasospasm after a subarachnoid hemorrhage. Although the reported effects of dilatation in clinical cases have been dramatic, few experimental studies of the mechanism of action have been performed. It also is still unclear why dilated arteries rarely show restenosis. Using the scanning electron microscope, we examined changes in the three-dimensional structure of connective tissues in vessel walls after balloon angioplasty. Femoral arteries from cats and middle cerebral arteries from human autopsies were studied. The vessels were dilated in situ with a balloon catheter until the intimal pressure reached 1.5 or 3 atm; then they were fixed and digested with 88% formic acid. The specimens were freeze dried and observed under the scanning electron microscope. Normal vessels without balloon dilatation were treated in the same manner and used as controls. The results showed that the normal structure of collagen fibers in the vessel walls was affected significantly by balloon dilatation. Stretched and torn fibers were observed frequently when 3 atm were applied. We concluded that the long-lasting effects of balloon dilatation may be caused by the disruption of connective tissues that proliferate in the vessel wall after a subarachnoid hemorrhage.

ISSN:0148-396X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Of 312 consecutive patients who were admitted to an emergency hospital because of subarachnoid hemorrhage (SAH), data on premonitory minor leaks were available on 303. Patients with an aneurysmal SAH had significantly (P< 0.05) more frequently (100 of 273, or 37%) a history of symptoms consistent with a previous minor leak than those with a hemorrhage of unknown etiology (4 of 30, or 13%). Aneurysmal SAH was associated with a poorer prognosis, more frequent occurrence of repeated bleeding and cerebral ischemia compared with SAH of unknown etiology, even in the good grade patients. The possible occurrence of a minor leak in poor grade patients may be even more frequent because the history obtained from family members was quite often uncertain. The outcome did not differ according to the evidence of previous minor leaks, but those who were admitted before a major rupture had a good outcome. The median time between a minor leak and major rupture was 14 days (range, 1 day to 4 mo). The correct diagnosis of a minor leak is important because early diagnosis and management can improve the overall outcome of this disastrous disease.

ISSN:0148-396X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Delayed ischemic neurological deficit (DIND) remains a major unsolved problem in the management of aneurysmal subarachnoid hemorrhage (SAH). For many years, the complications reported with acute aneurysm surgery caused surgeons to operate late after SAH. In a 42-month-period, we managed 146 patients with aneurysm and/or SAH. Forty-seven patients were characterized by the following: Hunt and Hess Grades I through III after an aneurysmal SAH; 2) clipping of their aneurysm within 72 hours of their SAH; and (3) prophylactic hypervolemia with a pulmonary artery catheter to optimize their fluid management. Forty of 47 (85%) had an excellent or good outcome, and 3 of 47 (6%) died. All of those who died had DIND. Nine of 47 (19%) patients developed DIND. There were 20 complications, primarily pulmonary edema, in 16 patients and one death related to prophylactic hypervolemia. It is not clear from our experience, when compared with results from other series, that hypervolemia provides any additional benefit to the patient as measured by a reduction in the risk of DIND or improved outcome. Despite aggressive volume expansion to the point of cardiovascular compromise, as evidenced by our high rate of pulmonary edema, we had no appreciable decrease in neurological morbidity and mortality when compared with results from recent reports.

ISSN:0148-396X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Prostaglandin E2, thromboxane B2, and 6-oxo-prostaglandin F1αwere assayed in blood and cerebrospinal fluid samples from patients after subarachnoid hemorrhage (SAH) and from a control population. The levels found in samples obtained from patients after SAH were compared with those found in controls and were also correlated with a number of clinical and radiological variables, many of which are either significantly associated with or represent evidence of cerebral ischemia. The levels of prostaglandin E2, thromboxane B2, and 6-oxo-prostaglandin F1αin blood samples from patients after SAH and from controls were below the level of sensitivity of the assays. Levels of prostaglandin E2, thromboxane B2, and 6-oxo-prostaglandin F1αin cerebrospinal fluid from patients after SAH were significantly elevated when compared with those found in control samples. There was no significant correlation, however, between the level of each prostaglandin measured and the following variables: clinical grade on admission as assessed by the Glasgow Coma Score and the World Federation of Neurological Surgeons grading system; the amount of subarachnoid blood seen on computed tomographic scan; the occurrence of ischemic deterioration; the occurrence of low density change on computed tomographic scan; the presence of vasospasm on angiography; clinical outcome as assessed by the Glasgow Coma Score 3 months after the ictus; and the incidence of ischemia as a cause of death or disability as assessed 3 months after the ictus. A primary role for prostaglandins in the etiology of delayed cerebral ischemia after SAH is not therefore confirmed.

ISSN:0148-396X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

The risk of neurotoxicity was evaluated in eight consecutive patients with non-acquired immunodeficiency syndrome (AIDS) primary central nervous system lymphoma who had survived disease free for more than 1 year after completion of treatment with osmotic opening of the blood-brain barrier and chemotherapy (methotrexate, cytoxan, procarbazine, and decadron). Trends in neuropsychological assessment results between baseline and follow-up (1 to 7 years) were analyzed for all eight nonradiated survivors. This serial assessment design addressed the specific issue of neurotoxic risk potential of treatment, when confounding factors of tumor persistence/recurrence and cranial irradiation were ruled out. Follow-up results of an extensive battery of tests to assess higher cortical function provided evidence of the safety of chemotherapy protocol with the blood-brain barrier disruption. These findings stand in contrast to well-known cognitive risks associated with cranial radiotherapy. Long-term follow-up suggests that chemotherapy can be given in conjunction with osmotic opening of the blood-brain barrier in nonradiated patients without cognitive manifestations of neurotoxicity.

ISSN:0148-396X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Basic mechanisms underlying the tolerance and reaction of the central nervous system to ionizing radiation are not known precisely. We investigated the possibility of a change in blood-brain barrier (BBB) function as a causative factor for early delayed whole-brain radiation-induced cerebral dysfunction. Rats were exposed to conventional fractionation (200 cGy/d, 5 d/wk; total dose, 4000 cGy). BBB changes were assessed by means of the quantitative14C-α-aminoisobutyric acid technique and electron microscopy. Studies of the passage of horseradish peroxidase across the BBB permitted comparative quantitative isotopical and qualitative morphological data. Experiments were carried out 2 to 3 weeks after the completion of the radiation exposure. The transport of14C-α-aminoisobutyric acid across the BBB increased significantly in cerebral cortex and cerebellar gray matter, averaging 1.3 to 1.5 times over the normal values. Electron microscopy disclosed an intense vesicular response of the cortical microvascular endothelium that occurred without the opening of the tight junctions and resulted in an intense transport of HRP across the intact endothelium. The present data indicate that moderate doses of whole-brain radiation induce well-defined changes in BBB function, which possibly are involved in the pathogenesis of radiation-induced cerebral dysfunction in humans.

ISSN:0148-396X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Fourteen patients with intradural extramedullary cysts of the spinal canal are described. Histological classification included 11 arachnoid, 2 epithelial, and 1 ependymal cyst. There were 9 thoracic, 3 cervical, and 2 lumbar cysts. The most common clinical presentation was a slowly progressive myelopathy. Twelve patients (85%) had objective neurological findings at the time of diagnosis. Radiographic diagnosis was made by a combination of myelography, computed tomographic scan with myelography, and magnetic resonance imaging. Complete surgical resection was accomplished for 8 dorsal cysts, and 6 ventral cysts were widely fenestrated into the subarachnoid space. Overall results were considered excellent or good in 9 patients, fair in 3, and poor in 2. There was one recurrence, which required a second operation. We conclude that the majority of intradural spinal cysts can be successfully managed surgically with a favorable clinical outcome.

ISSN:0148-396X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

The neuroradiological findings that revealed spinal cord transection/laceration in 6 patients with acute, blunt spinal trauma are described. Four patients suffered cervical spine injuries, and two had thoracic injuries. Initially, all patients had complete neurological deficit at the level of injury. The deficit improved in only 1 patient. On the basis of clinical history and spinal radiographs, spinal hyperflexion with distraction was the predominant mechanism of injury in our patients. Computed tomography with intrathecal contrast was performed on all patients and was always diagnostic. Visualization of intrathecal contrast material accumulating within the cord or the absence of cord shadow within the contrast column established the diagnosis in all cases. A dural tear was noted in 3 patients. Thoracic myelography was performed in 2 patients and, in both, demonstrated contrast pooling within the spinal cord at the level of the laceration. Magnetic resonance imaging was obtained in 1 patient and revealed an irregular, low-signal-intensity, intramedullary region extending to the cord surface on T1-weighted axial images. The myelographic and enhanced computed tomographic appearances of acute, traumatic spinal cord avulsion/laceration, which have been infrequently reported in the literature, are described.

ISSN:0148-396X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

The results of the treatment of trigeminal neuralgia by neurovascular decompression or partial sensory rhizotomy in a personal series of 220 patients are presented. Microvascular decompression was performed in 178 patients and partial sensory rhizotomy in 42. The mean follow-up was 5.2 years. Immediate pain relief was achieved in 94% of all patients, but the rate dropped to 84% during the follow-up period. The recurrence rate in the microvascular decompression group was 6% and in the PSR 49%. Permanent sequelae occurred in 4 patients (loss of hearing, 1; loss of corneal reflex, 1; lesion of the portio minor, 2), but transitory complications (impaired hearing caused by hematotympanum and diplopia) were more frequent, especially in the beginning of the series. Elderly patients tolerated the procedure very well and the percentage of complications was evenly distributed in all age groups. Three patients died. No patient developed painful dysesthesias or anesthesia dolorosa. There were no differences in the outcome, considering sex and age. The duration of symptoms did not influence the prognosis. Patients with severe compression did better than those with a mild one, and patients with an arterial compression did better than those with a venous one. Trigeminal neuralgia in multiple sclerosis is seldom relieved by microvascular decompression. The experience of the surgeon reduces the number of negative findings considerably.

ISSN:0148-396X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

The operative findings and results of microvascular decompression (MVD) on 310 Chinese patients with hemifacial spasm are analyzed in this report. The operations were performed at the Neurological Institute of the Veterans General Hospital-Taipei between January 1983 and June 1990. The length of follow-up ranged from 6 months to 8 years (mean, 4.3 years); 273 patients (88%) had complete relief of spasm within 3 days after one MVD, and the remaining 37 patients (12%) showed no immediate postoperative improvement. Sixteen (5.2%) of these 37 initially unresponsive patients subsequently experienced complete relief, which occurred from 4 days to 22 months (median, 21 days) after one MVD; 13 others (4.2%) had complete relief immediately after the second MVD; another 3 (1%) had delayed complete relief 6, 9, and 11 months after the second MVD, respectively; and the remaining 5 (1.6%) only had delayed partial relief, which occurred 2 to 9 weeks after one MVD. Late recurrence occurred in three patients (1%). These immediate and long-term results lend support to the conclusion that the timing of reoperation can be postponed for a period of 3 to 4 weeks in the event of an initial failure to get improvement, and that a second MVD may be of value.

ISSN:0148-396X    

出版商:OVID    

年代:1992

数据来源: OVID