Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0917798 (cerebral ischemia)
 17,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the past several years, improvements in technology have advanced the monitoring capabilities for patients with TBI. The primary goal of monitoring the patient with TBI is to prevent secondary insults to the brain, primarily cerebral ischemia. Cerebral ischemia may occur early and without clinical correlation and portends a poor outcome. Measurement of ICP is the cornerstone of monitoring in the patient with TBI. Monitoring of ICP provides a measurement of CPP and a rough estimation of CBF. However, with alterations in pressure autoregulation, measurement of CPP does not always allow for determination of CBF. To circumvent this problem, direct measurements of CBF can be performed using clearance techniques (133Xe, N2O, Xe-CT) or invasive monitoring techniques (LDF, TDF, NIRS). Although direct and quantitative, clearance techniques do not allow for continuous monitoring. Invasive CBF monitoring techniques are new, and artifactual results can be problematic. The techniques of jugular venous saturation monitoring and TCD are well established and are powerful adjuncts to ICP monitoring. They allow the clinician to monitor cerebral oxygen extraction and blood flow velocity, respectively, for any given CPP. Use of TCD may predict posttraumatic vasospasm before clinical sequelae. Jugular venous saturation monitoring may detect clinically occult episodes of cerebral ischemia and increased oxygen extraction. Jugular venous saturation monitoring optimizes the use of hyperventilation in the treatment of intracranial hypertension. Although PET and SPECT scanning allow direct measurement of CMRO2, these techniques have limited application currently. Similarly, microdialysis is in its infancy but has demonstrated great promise for metabolic monitoring. EEG and SEP are excellent adjuncts to the monitoring arsenal and provide immediate information on current brain function. With improvements in electronic telemetry, functional monitoring by EEG or SEP may become an important part of routine monitoring in TBI.
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PMID:Monitoring in traumatic brain injury. 1008 12

Anti-phospholipid antibody syndrome(APS) is characterized by the presence of antibodies to phospholipids and various symptoms including those derived from thrombosis. APS has been shown to be frequently accompanied by multiple and recurrent cerebral ischemic lesions, suggesting that APS may play a critical role in developing cerebral ischemia of unknown etiology. Here, we present a case with an unruptured cerebral aneurysm accompanied by a severe stenosis of the middle cerebral artery as a manifestation of APS. The aneurysm was successfully treated surgically employing the following precaution to prevent potential damage on the fragile ischemic brain: preoperative administration of anticonvulsant, intermittent brain retraction, intraoperative SEP monitoring, and postoperative administration of anticoagulant. Our experience suggests that unruptured cerebral aneurysms accompanied by APS could be safely treated by strict paraoperative management.
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PMID:[Surgical management for an unruptured cerebral aneurysm accompanied by anti-phospholipid antibody syndrome: a case report]. 1142 61

A standardized questionnaire was used to find out if and what kind of intraoperative cerebral monitoring method, respectively, is practised for carotid surgery in Germany. Out of 351 hospitals having received the questionnaire, 251 (75.1 %) answered the questions. 43 hospitals had not performed any carotid surgery in 1998, so 208 questionnaires remained for further analysis. In 43.3 % (n = 90), hospitals did not practise any kind of cerebral monitoring. In contrast, most hospitals monitored cerebral function and/or cerebral haemodynamics, intraoperatively. Median nerve somatosensory evoked potentials (SEP; n = 60) and electroencephalography (EEG; n = 39) dominated, whereas carotid stump pressure measuring (n = 40), transcranial Doppler sonography (TCD; n = 10), cerebral venous oximetry (n = 8) and near-infrared spectroscopy (n = 4) were used less frequently. In 60 hospitals, the indication to install temporary intraluminal shunting was based primarily on monitoring results. The results of our study mirror the present practice of intraoperative cerebral monitoring for carotid surgery in Germany. SEP monitoring is preferable because this method can reveal an imminent cerebral ischaemia with high sensitivity and specifity. TCD and cerebral oximetry are less suitable for this purpose. Measuring carotid stump pressure is not recommendable to reflect the status of cerebral haemodynamics, however this method is still in frequent use. Recommendations whether to practise cerebral monitoring or not, and what method should be used for this purpose, cannot be given presently.
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PMID:[Cerebral monitoring in carotid surgery. Results of a questionnaire in the Federal Republic of Germany]. 1170 94

We review the principal aspects of EEG and SEP to detect and prevent cerebral ischaemia in the operating room during interventions at risk. EEG and SEP are variables that indirectly reflect cerebral blood flow (CBF) provided that anaesthetic regimen, body temperature, and arterial blood pressure of the patient are stable. When CBF decreases and reaches the functional threshold, slowing and/or attenuation of EEG occurs while the amplitude and the latency of cortical SEP are, respectively decreased and lengthened. Based on these changes, numerous criteria corresponding to critical thresholds have been defined. A decrease in EEG amplitude greater than 30% or EEG changes lasting more than 30 s have been considered as significant by clinicians. The main criteria resulting from computerized EEG analysis were a reduction in total power and/or in spectral edge frequency. Regarding SEP, a more than 50% decrease in N20 amplitude and/or a more than 1 ms increase in central conduction time were the most frequently used criteria. According to the bulk of literature, it may be concluded that processed EEG analysis is more sensitive than visual EEG analysis to detect cerebral ischaemia, and that SEP are not less sensitive than conventional EEG. Moreover, literature shows that SEP are as specific as computerized EEG analysis to disclose ischaemia during carotid endarterectomy.
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PMID:Electroencephalography (EEG) and somatosensory evoked potentials (SEP) to prevent cerebral ischaemia in the operating room. 1503 Jul 97

In the neurosurgical field, the evoked potential is employed for the monitoring of intraoperative nerve function. During evoked potential monitoring, surgical manipulation-related nerve dysfunction is detected, and functional localization/nerves in the cerebral cortex are identified to prevent postoperative neurological complications. It is important to reduce the contact resistance to 2 kOmega or less on the application of plate electrodes used for recording and prevent noise by bundling electrode leads, to ensure a stable evoked potential during surgery. In our laboratory, intraoperative monitoring, such as ABR to prevent auditory disturbance, SEP to detect cerebral ischemia, cortical SEP and MEP to prevent motor paralysis, and evoked electromyography to identify/maintain the cranial nerves including the facial, trigeminal, oculomotor, and abducens nerves, is performed based on requests from the Department of Neurosurgery.
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PMID:[Evoked potential monitoring in an operation of neurosurgery]. 1864 33


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