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Biomedical subjects

D O Quest

Publications and source records attributed to D O Quest.

At least 37 records · Page 2Linked to original sources
PubMed1989

Cerebral revascularization: a review.

A review of the development and current methods of surgical revascularization of the cerebral circulation is presented. In addition to the conventional superficial temporal artery to middle cerebral artery (STA-MCA) bypass, the techniques of interposition vein grafting and vertebrobasilar revascularization are discussed. The results and implications of the International Cooperative Study are reviewed. Extracranial-intracranial (EC-IC) bypass grafting remains an essential procedure in the treatment of many cerebrovascular conditions, including Moya Moya disease and giant intracranial aneurysms. The efficacy of interposition vein grafts, as well as the EC-IC bypass in the treatment of vertebrobasilar insufficiency, acute cerebral ischemia, cerebral vasospasm, and multi-infarct dementia, remains to be determined. Several alternative revascularization procedures, including proximal MCA anastomosis and omental transposition, are in development.

Brain Diseases↗
PubMed1988

Electroencephalographic monitoring for ischemia during carotid endarterectomy: visual versus computer analysis.

In a retrospective study, we compared the use of computer-generated spectral electroencephalographic descriptors with a neurologist's interpretation of raw EEG data. Data were collected from patients undergoing carotid endarterectomy and anesthetized with isoflurane in nitrous oxide and oxygen. The EEG was recorded on magnetic tape during the period immediately before and after occlusion. These tapes were then analyzed off-line using a computer to generate averaged changes in 18 spectral descriptors. A strip-chart of raw EEG before and after the carotid occlusion was interpreted by a neurologist, who assigned changes in the EEG following occlusion to one of four visual inspection groups, depending on the severity of change. A descriptive examination of the distribution of changes in spectral descriptors revealed that no single descriptor adequately reflected the neurologist's interpretation of the raw EEG. Using data from 20 patients, the percent change from preocclusion to postocclusion values for total power, spectral edge frequency, spectral variance, and log spectral variance was examined. Only for the visual inspection group judged by the electroencephalographer to have the most severe ischemic change was there a significant difference in total power and log spectral variance. Although computer-processed EEG devices are of value as trending devices for detecting visual patterns associated with inadequate cerebral perfusion, single descriptors in this study did not consistently reflect a neurologist's diagnosis of ischemia. Single descriptors of spectral EEG analysis may not be sufficient to use as alarm variables in the recognition of cerebral ischemia.

Brain Ischemia↗
PubMed1988

Reduced hypercapnic vasoreactivity in moyamoya disease.

We measured cerebral perfusion at rest and in response to CO2 in eight patients with moyamoya disease (MMD), using the 133xenon inhalation method to determine the effect of large-vessel occlusive disease on vasoreactivity. We studied three other groups for comparison, including four with bilateral internal carotid artery occlusions (BICAO), 11 with unilateral carotid occlusion (UICAO), and six with unilateral middle cerebral artery stem occlusion (UMCAO). Resting flows appeared to correlate with the severity of occlusive disease overall. Normocapnic perfusion was lowest in the group with BICAO and decreased in proportion to the degree of contralateral stenosis in the group with UICAO. Hypercapnic perfusion correlated with the apparent adequacy of angiographic collaterals. Reactivity was lowest in the MMD group (0.79%/mm Hg) whose collateral supply was limited to leptomeningeal anastomosis from the posterior cerebral artery, but highest in the patients with BICAO (2.72%/mm Hg), each of whom showed excellent posterior communicating artery flow. The clinical course of the MMD group was compatible with the syndrome of perfusion insufficiency with repeated ischemic attacks or a saltatory progression of an ischemic deficit; CT showed infarction in the borderzone territory. These results suggest that a severely reduced hypercapnic response may help to identify patients with ischemic syndromes due to perfusion failure in the borderzones, as in MMD.

Adult↗
PubMed1987

Technical controversies in carotid artery surgery.

Carotid endarterectomy has become a routine and safe therapeutic strategy in most neurovascular centers. Wide diversity of opinion and considerable debate, however, persists concerning the ideal methods of anesthetic management, cerebral protection, intraoperative monitoring, and arterial repair. We have examined and summarized the current status of these controversies and have identified several new techniques that hold promise for further development.

Anesthesia↗
PubMed1987

Neurotrauma care and the neurosurgeon: a statement from the Joint Section on Trauma of the AANS and CNS.

The AANS and CNS support the concept of organized neurosurgical trauma care consisting of the appropriate combination of prepared communities and institutions and of adequate numbers of committed neurosurgeons. Furthermore, we support the guidelines of the ACS regarding institutions designated to receive trauma patients, and support the concept of prehospital triage of trauma victims based upon well-trained EMS personnel guided by criteria selected by the local neurosurgical community. We support audit systems that include neurosurgeons to assess and improve the quality of neurotrauma care. By using the principles outlined above, neurosurgeons can plan, support, and evaluate whatever system their community or region requires for the optimal care of the neurotrauma patient.

Health Planning Guidelines↗
PubMed1987

Carotid endarterectomy for stroke prevention.

Minor neurologic signs or transient ischemic attacks (TIAs) precede stroke in 50 percent of patients. In men, antiplatelet therapy decreases the risk of recurrent TIA and stroke. Carotid endarterectomy for TIA is now one of the most commonly performed vascular operations. Preoperatively, the arterial anatomy of the patient must be carefully studied by conventional angiography or digital subtraction angiography. The goal of surgery is to eliminate the atherosclerotic plaque and restore the artery to its normal size with a smooth intima.

Anticoagulants↗
PubMed1986

Incidence and etiology of intracerebral hemorrhage following carotid endarterectomy.

In a consecutive series of 1930 carotid endarterectomies there were eight cases of postoperative intracerebral hemorrhage. One of these patients was operated on 2 weeks following cerebral infarction and had severe uncontrollable hypertension after surgery. A second patient had an intraoperative embolus and bled while fully heparinized on the 3rd postoperative day. Only one patient in the series bled into an area of documented cerebral infarction. The remainder of the cases represented hemorrhage into essentially normal brain. Seven of the eight patients with intracerebral hemorrhage had high-grade internal carotid artery stenosis preoperatively. Although several factors have contributed to the brain hemorrhages in this series of patients, postoperative cerebral hyperperfusion which often follows endarterectomy may have played an important role. Defective cerebrovascular autoregulation in chronically ischemic brain regions may predispose patients to intracerebral hemorrhage after removal of a high-grade stenosis of the internal carotid artery.

Aged↗
PubMed1985

Basal arterial occlusive disease.

Seventeen patients with basal occlusive disease have been seen over the past 4 years. Nine of these had a classical moyamoya appearance on angiography. Of these nine, seven were adults and two were children. Eight had ischemic episodes, and one had a hemorrhage. One had neurofibromatosis with a chiasmal glioma and had received radiotherapy. Eight patients underwent superficial temporal-middle cerebral artery (STA-MCA) bypass, and one refused operation. Six patients improved, one had a stroke on the opposite side, and one died. Eight patients had unilateral basal arterial occlusive disease. Of these, three had ischemic episodes, four had hemorrhages, and one had only headaches. Four were adults, and four were children. Five underwent STA-MCA bypass with improvement, one with headaches had an aneurysm treated, and two were not operated upon. Considerations regarding the cause, therapeutic options, and disease course in these patients are discussed.

Adult↗
PubMed1983

Seizures during the immediate postoperative period.

Twenty-three of 538 patients undergoing elective craniotomy had a seizure within 24 hours after operation. The lesion had been located extra-axially in 15 patients and intra-axially in 8 patients. Except for 1 patient who had a parietal craniotomy for an arteriovenous malformation, all patients had a frontal or temporal exposure. Only 5 patients had a previous history of seizures. Adequate levels of anticonvulsant medication were not present in 19 of the 23 patients before operation. No major postoperative metabolic abnormalities were noted in any of the 23 patients. Thirteen of the 23 patients underwent computed tomography to evaluate the etiology of their seizures; none had a significant intracerebral or extracerebral hematoma. This review suggests that an early postoperative seizure is unlikely to be due to a postoperative hematoma or to metabolic abnormality. The most common association in this series was with inadequate anticonvulsant prophylaxis. An approach to postoperative seizure prophylaxis and management is presented.

Brain↗
PubMed1983

Computerized electroencephalogram monitoring and carotid artery shunting.

During carotid artery surgery, ischemic electroencephalogram (EEG) changes were detected by computerized analysis in 27 of 225 carotid clamping intervals. All but 7 of these changes resolved spontaneously before the restoration of blood flow. Restored flow was associated, after variable delay, with an improved EEG pattern in 6 of 7 cases. Of 27 EEG episodes, there were 5 cases in which the EEG event persisted for 10 minutes or longer. All 5 patients developed new neurological deficits; none of the other patients did. It is suggested that all patients undergoing carotid artery surgery be monitored with EEG and that a shunt be placed if a persistent EEG change is noted.

Aged↗
PubMed1983

Current status of carotid endarterectomy for atheromatous disease.

The authors discuss the indications for both elective and emergency carotid endarterectomy. Reports on the surgical treatment of asymptomatic bruit and contralateral carotid stenosis are reviewed. The results of endarterectomy for symptomatic carotid disease, including transient ischemic attacks, acute neurological deficit, and complete carotid occlusion, are discussed. The complications and risks of carotid surgery are also presented.

Carotid Artery Diseases↗
PubMed1983

Prognostic value of computerized EEG analysis during carotid endarterectomy.

A single-channel EEG, analyzed in real time to produce a density spectral array (DSA) display was recorded during 111 carotid endarterectomies. A simple protocol that emphasized loss of high frequency activity was used to identify serious ischemic EEG events. In 70 patients (78 operations) with no preoperative neurologic deficits, new postoperative neurologic deficits appeared only in the seven patients who had ischemic EEG events that lasted 10 min or longer. The EEG was not predictive in the 31 patients (33 operations) who had preoperative neurologic deficits: one patient with no intraoperative change in EEG developed a new postoperative deficit, and one patient with EEG changes lasting 13 min had no demonstrable new deficit postoperatively. This EEG monitoring technique was simple and convenient to use, and appears to be predictive of gross neurologic outcome following carotid endarterectomy in patients without preoperative neurologic deficits.

Aged↗