摘要:

THERE IS CONSIDERABLE confusion in the literature regarding the pathological substrates of angiographically occult vascular malformations (AOVMs) of the brain and their clinical significance. We retrospectively reviewed the cases of 34 consecutive patients with AOVMs undergoing surgical excision at a single institution during a 10-year period. Pathological specimens were reexamined, and the lesions were classified according to strict histopathological criteria. There were 21 cavernous malformations, 3 arteriovenous malformations, 3 venous malformations, 2 capillary malformations, and 5 mixed (pathologically heterogeneous) lesions. The initial pathological diagnostic report had been imprecise or had misidentified the lesion type in 18 of the 34 cases (53%), most commonly labeling a cavernous malformation as an arteriovenous malformation or not recognizing mixed features within the same lesion. Clinical presentation (including hemorrhage) and outcome were not significantly different among the various lesion types. Preoperative diagnostic imaging included a variety of modalities that were introduced or evolved during the period of the study and generally suggested a suspected vascular malformation but did not predict pathological subtypes. Acute hematomas in this surgical series made the identification of underlying vascular malformations highly speculative. We conclude that the majority of AOVMs requiring surgical intervention are cavernous malformations, although there was a notable pathological heterogeneity of the remaining lesions. Histopathological subtypes of AOVMs are not associated with unique clinical or radiographic features.

ISSN:0148-396X    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

CONGENITAL ARTERIOVENOUS MALFORMATION (AVM) of the brain represents a defect in capillary development resulting in a high flow fistula between arterial and venous systems. In this study, AVM hemodynamics were related with clinical findings. Volume flow was calculated based on transcranial Doppler (TCD) and angiographic data. Forty patients admitted to the Massachusetts General Hospital for proton beam therapy (33 ± 10 yr old; mean ± SD) were studied. Four symptoms were considered: intracranial bleeding, progressive neurological deficit, seizures, and headache. Fourteen control subjects aged 30 ± 7 years (mean ± SD) were normal volunteers. Angiography with calibrated markers permitting magnification correction was available for all patients. Lateral and medial depth limits of the intracranial basal arteries in relation to the TCD temporal window were determined by TCD and angiogram with excellent correlation. Selected depth for data acquisition was determined independently in the angiogram and by TCD. The difference between the two techniques was less than 4 mm. Mean flow velocity, pulsatility index, and vessel diameter were studied. Flow volume was calculated from these data. Mean flow velocity, pulsatility index, vessel diameter, and flow volume were significantly different among AVM feeders, non-feeders, and control arteries. The non-feeding middle cerebral artery, anterior cerebral artery, and posterior cerebral artery flows were 254 ± 13, 136 ± 14, and 79 ± 8 ml/min, respectively. Accordingly, the estimated cerebral flow volume was 938 ml/min. The feeding middle cerebral artery, anterior cerebral artery, and posterior cerebral artery flows were 552 ± 47, 369 ± 70, and 484 ± 67 ml/min, respectively (P< 0.001). The mean flow volume to the AVMs was 913 ± 227 ml/min, and patients having hemorrhage had significantly lower flow volume (624 ± 117 ml/min,P< 0.01) than patients having other symptoms. TCD accurately determined the depth limits of the basal cerebral arteries measured against the angiographic determinations. The evaluation of flow volume with vessel diameter measured in the angiogram and flow velocity was close to that reported by authors using other techniques. Analysis of these data disclose important hemodynamic patterns related to AVM symptomatology. These patterns may have therapeutic implications.

ISSN:0148-396X    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

IN A COHORT of 14 patients suffering from cerebral arteriovenous malformations (AVM), neuropsychological functioning was examined before and after AVM resection. Improvements after surgery were assumed to be due to enhanced neurocognitive functions associated with the hemisphere ipsilateral to the AVM, and to a lesser extent, with the contralateral hemisphere. Before surgical intervention, the performances of AVM patients were deficient relative to matched normals. Postoperatively, neuropsychological gains were observed particularly in the areas of learning, memory, and higher integrative thought, not only for ipsilateral, but also for contralateral functioning. Contralateral and ipsilateral improvement is consistent with the premise that cerebrovascular steal is lessened; thus, neurosurgical intervention to eliminate arteriovenous shunts was found to result in overall neurobehavioral gains.

ISSN:0148-396X    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

IN THIS PROSPECTIVE study, a series of 89 patients with subarachnoid hemorrhage (SAH), most of whom had a “good” neurological outcome, were assessed with a range of tests of memory and cognition as inpatients and at 10 weeks and 12 months after SAH. On tests of verbal cognition and memory, most patients had scores in the normal range 12 months after SAH. However, a significant number of patients still showed impairment on tests of visuospatial construction and memory, mental flexibility, and psychomotor speed at the 12-month assessment. Statistical analyses were carried out for each test score to see whether aneurysm site, location of blood on the admission computed tomographic scan, vasospasm, ischemia, hydrocephalus, grades at admission to and at discharge from hospital, and Glasgow Outcome Scale score at follow-up were associated with test scores. Aneurysm site was not shown to be associated with performance on any test at any time, and the other complications of SAH had only minimal predictive value. The grade at discharge proved to be the best predictor of impairment of cognition and memory at both follow-up assessments. Older subjects did not recover to the same extent as younger subjects by the 12-month assessment. The authors conclude that the diffuse effects of SAH are more important than focal neuropathology in relation to cognitive impairment in this group of patients.

ISSN:0148-396X    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

EARLY IN THE course of treating arteriovenous malformations with radiosurgery, it was noted that the nidus isocenter and diameter, as identified by stereotactic angiography, often differed from that identified by stereotactic enhanced computed tomography (CT). To assess the sources of discrepancy between the arteriographic and CT representations of the nidus, dosimetry (from treatment records stored on an optical disk) was reviewed in 81 consecutive cases. In 44 cases, the isocenters differed by an average of 3.6 mm and the collimator size differed. Fourteen nidi were larger on CT (average, 2.6 mm), and 30 were smaller on CT (average, 4.0 mm). Overall, the angiographic and the CT nidus differed in 75% of the cases reviewed. Sources of error in the angiographic nidus determination included overlapping vessels, bony structures, fine filamentous arterioles, and irregular shapes.

ISSN:0148-396X    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

MICROSURGICAL RESECTION IS the primary management approach for patients with intracranial schwannomas. Recent studies have demonstrated that stereotactic radiosurgery is an effective therapeutic modality for patients with acoustic schwannomas. To define the role of radiosurgery in the management of patients with nonacoustic schwannomas, we reviewed the results of gamma unit stereotactic radiosurgery in six patients with trigeminal and five patients with jugular foramen region schwannomas. No patient with a trigeminal schwannoma demonstrated tumor growth during a mean follow-up of 21 months (range, 7–35 mo), whereas one patient with a jugular foramen region schwannoma had an increase in tumor size 7 months after radiosurgery. No new cranial nerve or brain stem deficits were noted in either patient group after radiosurgery. In this early experience, radiosurgery proved an effective primary or adjuvant technique for selected patients with schwannomas of the trigeminal, glossopharyngeal, or vagus nerves. Using our described method, the safety of radiosurgery was demonstrated on the brain stem, regional cranial nerves, and especially those cranial nerves intimately associated with the tumor.

ISSN:0148-396X    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

THIRTY-SEVEN PATIENTS WITH pituitary apoplexy were analyzed with an emphasis on clinical presentation and visual outcome. Their mean age was 56.6 years, with a male to female ratio of 2:1. Presenting symptoms included headache (95%), vomiting (69%), ocular paresis (78%), and reduction in visual fields (64%) or acuities (52%). Computed tomographic scanning correctly identified pituitary hemorrhage in only 46% of those scanned. Thirty-six patients underwent transsphenoidal decompression. By immunostaining criteria, null-cell adenomas were the most frequent tumor type (50%). Long-term steroid or thyroid hormone replacement therapy was necessary in 82% and 89% of patients, respectively. Long-term desmopressin therapy was required in 11%, and 64% of the male patients required testosterone replacement therapy. Surgery resulted in improvement in visual acuity deficits in 88%, visual field deficits in 95%, and ocular paresis in 100%. Analysis of the degree of improvement in preoperative visual deficits with the timing of the surgery demonstrated that those who underwent surgery within a week of apoplexy had significant recovery in their visual acuities. In the stable, conscious patient with residual vision in each eye, surgical decompression should be performed as soon as possible, because delays beyond 1 week may retard the return of visual function.

ISSN:0148-396X    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

WE PRESENT 25 pituitary adenomas that were confirmed surgically to have invaded the cavernous sinus space. The surgical results are compared with the preoperative magnetic resonance imaging findings. For comparable radiological criteria, we classified parasellar growth into five grades. This proposed classification is based on coronal sections of unenhanced and gadolinium diethylene-triamine-pentaacetic acid enhanced magnetic resonance imaging scans, with the readily detectable internal carotid artery serving as the radiological landmark. The anatomical, radiological, and surgical conditions of each grade are considered. Grades 0, 1, 2, and 3 are distinguished from each other by a medial tangent, the intercarotid line--through the cross-sectional centers--and a lateral tangent on the intra- and supracavernous internal carotid arteries. Grade 0 represents the normal condition, and Grade 4 corresponds to the total encasement of the intracavernous carotid artery. According to this classification, surgically proven invasion of the cavernous sinus space was present in all Grade 4 and Grade 3 cases and in all but one of the Grade 2 cases; no invasion was present in Grade 0 and Grade 1 cases. Therefore, the critical area where invasion of the cavernous sinus space becomes very likely and can be proven surgically is located between the intercarotid line and the lateral tangent, which is represented by our Grade 2. We also measured tumor growth rates, using the monoclonal antibody KI-67, which shows a statistically higher proliferation rate (P< 0.001) in adenomas with surgically observed invasion into the cavernous sinus space, as compared with noninvasive adenomas.

ISSN:0148-396X    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

WE DESCRIBE A technique for estimating the number of proliferating cells in gliomas and adjacent resection cavities after tumor removal. Proliferating cell nuclear antigen (PCNA) is a nuclear protein associated with the cell cycle. Anti-PCNA antibody staining provides a semiquantitative estimate of the number of proliferating cells found in fixed tissue embedded in paraffin. The extent of the staining of tumor cells of glioblastoma multiforme, anaplastic astrocytomas, low-grade gliomas, and other lesions of the brain with anti-PCNA antibody is correlated with the histological diagnosis. In addition, the labeling of the margins after resection of gliomas and other lesions with anti-PCNA antibody is also associated with the histological diagnosis of the lesion. This technique may be useful in estimating the “biological” extent of resection and in predicting the recurrence patterns of gliomas.

ISSN:0148-396X    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

THE MANAGEMENT OF low-grade astrocytomas remains a challenge. Although the majority of these tumors have common histological features, they may have very different clinical manifestations and rates of proliferation. Because low-grade astrocytomas are composed of relatively well-differentiated neoplastic cells that closely resemble the astrocytic phenotype, it is possible that some of these lesions express antigens that characterize astrocyte lineages. The authors performed an immunohistochemical analysis of 20 low-grade astrocytomas with A2B5, a monoclonal antibody to a ganglioside found in early postnatal Type 2 (fibrillary) astrocytes, but absent in Type 1 (protoplasmic) astrocytes, and anti-glial fibrillary acidic protein to determine whether the expression of these antigens could be used to determine the histogenesis of these tumors. These findings were compared with the clinical and imaging features of these tumors. The percentages of cells positive for A2B5 and glial fibrillary acidic protein was strongly correlated with the location of the tumor within the cortex or white matter and with the length of preoperative symptoms. Tumors based in the cortex contained significantly fewer A2B5-positive and glial fibrillary acidic protein-positive cells than white matter tumors. In addition, lesions that caused a relatively short period of preoperative symptoms (<1 year) had significantly more A2B5-positive and glial fibrillary acidic protein-positive cells than lesions responsible for a long preoperative history (mean, 12.9 years). These findings suggest that slow-growing, cortically based low-grade astrocytomas have a phenotype consistent with the Type 1 (protoplasmic) astrocyte lineage, while white matter low-grade astrocytomas express antigens consistent with the Type 2 (fibrillary) astrocyte lineage.

ISSN:0148-396X    

出版商:OVID    

年代:1993

数据来源: OVID