Journal of neurosurgery
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Journal of neurosurgery · Jan 2002
Regional cerebrovascular and metabolic effects of hyperventilation after severe traumatic brain injury.
Recently, concern has been raised that hyperventilation following severe traumatic brain injury (TBI) could lead to cerebral ischemia. In acute ischemic stroke, in which the baseline metabolic rate is normal, reduction in cerebral blood flow (CBF) below a threshold of 18 to 20 ml/100 g/min is associated with energy failure. In severe TBI, however, the metabolic rate of cerebral oxygen (CMRO2) is low. The authors previously reported that moderate hyperventilation lowered global hemispheric CBF to 25 ml/100 g/min but did not alter CMRO2. In the present study they sought to determine if hyperventilation lowers CBF below the ischemic threshold of 18 to 20 ml/100 g/ min in any brain region and if those reductions cause energy failure (defined as a fall in CMRO2). ⋯ After severe TBI, brief hyperventilation produced large reductions in CBF but not energy failure, even in regions in which CBF fell below the threshold for energy failure defined in acute ischemia. Oxygen metabolism was preserved due to the low baseline metabolic rate and compensatory increases in OEF; thus, these reductions in CBF are unlikely to cause further brain injury.
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Journal of neurosurgery · Jan 2002
A proposed radiosurgery-based grading system for arteriovenous malformations.
Radiosurgery is an effective treatment strategy for properly selected patients harboring arteriovenous malformations (AVMs). Grading scales that are currently used to predict patient outcomes after AVM resection are unreliable tools for the prediction of the results of AVM radiosurgery. ⋯ Despite significant differences in preoperative patient characteristics and dose prescription guidelines at the two centers, the proposed AVM grading system strongly correlated with patient outcomes after single-session radiosurgery for both patient groups. Although further testing of this model by independent centers using prospective methodology is still required, this system allows a more accurate prediction of outcomes from radiosurgery to guide choices between surgical and radiosurgical management for individual patients with AVMs.
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Journal of neurosurgery · Jan 2002
Case ReportsVascular complications in anterior thoracolumbar spinal reconstruction.
Anterior approaches in thoracic and lumbar spinal surgery have potentially serious vascular injury-related complications. In this study the authors evaluate the incidence of vascular complications in anterior approaches to the thoracic and lumbar spine in cases requiring reconstructive surgery. ⋯ Vascular injury to the great vessels is a known and potentially serious complication associated with anterior spinal reconstructive procedures. The authors found, however, that the incidence is relatively low in cases in which venous injuries occurred acutely and arterial injuries presented in a delayed fashion.
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Journal of neurosurgery · Jan 2002
Comparative StudyComparative study of traumatic and spontaneous intracerebral hemorrhage.
Spontaneous intracerebral hemorrhage (SICH) and traumatic intracerebral hemorrhage (TICH) are common disorders. The authors planned to study how these two types of hemorrhage behave pathologically and clinically to gain further insight into their causes, pathogeneses, indications for surgical intervention, and prognoses. ⋯ On the basis of these data the authors suggest that TICH and SICH have different features: TICH affects a slightly younger age group and carries a much better prognosis compared with SICH. In addition, indications for surgical intervention are not well defined for either type of hemorrhage. Practice is subjective and inconsistent. The International Surgical Trial in Intracerebral Haemorrhage may resolve the dilemma for SICH. A similar trial in which surgery is compared with conservative management should be considered for cases of TICH.
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Journal of neurosurgery · Jan 2002
Outcome prediction with serum intercellular adhesion molecule-1 levels after aneurysmal subarachnoid hemorrhage.
Although upregulated adhesion molecule expression has been demonstrated in experimental models of subarachnoid hemorrhage (SAH) and in the cerebrospinal fluid of patients with aneurysmal SAH, the clinical significance of these proinflammatory findings remains unclear. The authors hypothesize that 1) serum levels of soluble intercellular adhesion molecule-l (ICAM-1) are increased in all patients with aneurysmal SAH shortly after the hemorrhagic event, and 2) elevated soluble ICAM-1 values are associated with poor patient outcome, even when controlling for the severity of the initial hemorrhagic insult. ⋯ These data demonstrate a correlation between soluble ICAM-1 levels and functional outcome following aneurysmal SAH that appears to be, at least in part, independent of the initial hemorrhage.