Neurological research
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Neurological research · Apr 2002
ACoA angle measured by computed tomographic angiography and its relevance in the pterional approach for ACoA aneurysms.
The purpose of this study was to analyze the spatial disposition of the anterior communicating artery (ACoA) complex and the orientation of the ACoA plane by computed tomographic angiography with three-dimensional reconstruction (3D-CTA) and to evaluate the relevance of the orientation of the ACoA plane in the planification of the surgical approach to the ACoA complex aneurysms. The dominance of the right or left A1 segment of the anterior cerebral artery, the position of the A1-A2 junction in relation to the transverse plane and the angulation of plane of the ACoA traject were studied using 3D-CTA in 30 patients with subarachnoid hemorrhage. Twelve patients harbored an aneurysm on the ACoA complex and the most relevant anatomic characteristics of these lesions were recorded. ⋯ The angulation of the ACoA plane, in combination with the orientation of the aneurysm, must be included among the criteria for the selection of the route of the surgical approach. This information is given by the 3D-CTA. All of these data allows a pre-operative simulation of the surgical approach to the lesion for a safer clipping of the neck of the aneurysm.
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The singular anatomical relationship of the base of the skull is responsible for the particular problems that may arise after injury. Extensive dural laceration and severe neurovascular damage may accompany skull base injuries. Trauma to the anterior skull base is frequently related to the paranasal sinuses, and trauma to the middle and the posterior skull base usually affects the petrous bone. ⋯ Decisions regarding the timing of surgery and the sequence of the surgical procedures must be made with great care. Modern surgical techniques and recent technologies including functional preservation of the olfactory nerves in frontobasal trauma, visual evoked potentials, assisted optic nerve decompression, facial nerve reconstruction, interventional technique for intravascular repair of vascular injuries, and recent developments in cochlea implants and brain stem implants, all contributed significantly to improve outcome and enhance the quality of life of patients. This article reviews basic principles of management of skull base trauma stressing the role of these advanced techniques.
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Neurological research · Mar 2002
Vascular tunnel construction in the treatment of severe brain swelling caused by trauma and SAH. (evidence based on intra-operative blood flow measure).
Decompressive craniectomy with durotomy, is possible as a last resort therapy for severe traumatic brain swelling. Although the method successfully diminishes the ICP, partial or total vascular insufficiency occurs in the herniated part of the brain. The actual cause of the insufficiency is most likely due to the compression of the cortical veins and arteries supplying the herniated brain, caused by shearing and pressure forces between the dural edge and brain tissue. ⋯ In comparison with the traditional surgical and nonsurgical treatment, where the reported mortality rates are 80%-90% in these severe cases the mortality rate was reduced to 40%, and recovery (GOS 4, 5) rate also increased significantly. With this technique the ICP was significantly reduced and further edema and vascular insufficiency was prevented. This was due to protection of the arterial circulation and venous drainage of the herniated part of the brain, by the formation of a vascular tunnel at the durotomy edges.
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Neurological research · Mar 2002
Relationship between brain temperature, brain chemistry and oxygen delivery after severe human head injury: the effect of mild hypothermia.
We studied brain temperature and the effect of mild hypothermia in 58 patients after severe head injury (SHI). Brain tissue oxygen tension (ptiO2), carbon dioxide tension (ptiCO2), tissuie pH (pHti) and temperature (T.br) were measured using a multiparameter probe. Microdialysis was performed to measure glucose, lactate, glutamate, and aspartate in the extracellular fluid. ⋯ Induced hypothermia may protect patients from secondary ischemic events by lowering the critical ptiO2 threshold, reducing anaerobic metabolism, and decreasing the release of excitatory aminoacids. However, patients with spontaneous brain hypothermia on admission (Tbr < 36.0 degrees C) showed significantly higher levels of glutamate as well as lactate, compared to all other patients, and had a worse outcome. Spontaneous brain hypothermia carries a poor prognosis, and was characterized by markedly abnormal brain metabolic indices.
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The outcomes of devastating neurological emergencies such as stroke and subarachnoid hemorrhage may be measurably improved by timely treatment in a neurointensive care unit (NICU). Optimal care requires a multidisciplinary approach, with attention to a wide range of treatment issues. This review examines the key therapeutic concerns in the NICU management of acute ischemic and hemorrhagic stroke and subarachnoid hemorrhage, including mechanical ventilation, blood pressure management, cardiac monitoring, intracranial pressure assessment, vasospasm, seizures, sedation, fluids, electrolytes, and nutrition. ⋯ The discussion of vasospasm includes evaluation, prophylaxis, and treatment with medications, hypervolemic hemodilution, and angioplasty. Management of seizure and status epilepticus in stroke and subarachnoid hemorrhage are reviewed and current algorithms are presented. The management of fluids, electrolytes and enteral nutrition are also reviewed.