Journal of neurosurgery
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Journal of neurosurgery · Jan 2000
Microanatomical variations in the cerebellopontine angle associated with vestibular schwannomas (acoustic neuromas): a retrospective study of 1006 consecutive cases.
Great advances in neuroimaging, intraoperative cranial nerve monitoring, and microsurgical technique have shifted the focus of acoustic neuroma surgery from prolonging life to preserving cranial nerve function in patients. An appreciation of the vascular and cranial nerve microanatomy and the intimate relationship between neurovascular structures and the tumor is essential to achieve optimum results. In this paper the authors analyze the microanatomical variations in location of the facial and cochlear nerves in the cerebellopontine angle (CPA) associated with acoustic neuromas and, additionally, describe the frequency of involvement of surrounding neural and vascular structures with acoustic tumors of varying size. The authors base these findings on their experience with 1006 consecutive patients who underwent surgery via a retrosigmoid or translabyrinthine approach. ⋯ In this study, the authors show the great variation in anatomical location and involvement of neurovascular structures in the CPA. With this knowledge, they present certain technical lessons that may be useful in preserving nerve function during surgery and, in doing so, hope to provide neurosurgeons and neurootologists with valuable information that may help to achieve optimum outcomes in patients.
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Journal of neurosurgery · Jan 2000
Endoscopic management of cysticercal cysts within the lateral and third ventricles.
In this report the authors review their 3-year experience with the endoscopic management of patients with hydrocephalus who harbored cysticercal cysts within the third and lateral ventricles. The management plan was to utilize an endoscopic approach to remove the cysts and to incorporate techniques useful in treating obstructive hydrocephalus. The ultimate goals were to avoid having to place a complication-prone cerebrospinal fluid shunt and to eliminate the risk of complications related to cyst degeneration. ⋯ The endoscopic removal of third and lateral ventricle cysticercal cysts, combined with a third ventriculostomy or septum pellucidotomy in selected cases, is an effective treatment in patients with hydrocephalus and should be considered the primary treatment for this condition.
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Journal of neurosurgery · Jan 2000
Surgical correction of lumbar kyphotic deformity: posterior reduction "eggshell" osteotomy.
Progressive kyphotic deformity of the lumbar or thoracolumbar spine may lead to back pain, cosmetic deformity, and risk of neurological compromise. The authors describe a series of patients in whom they performed a single-stage, posterior reduction ("eggshell") osteotomy procedure to improve sagittal contour by creating lordosis within a single vertebral body. ⋯ Single-level posterior reduction osteotomy provides excellent sagittal correction of kyphotic deformity in the lumbar region, with a risk of cauda equina and root and plexus compromise due to the extensive neural exposure.
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Journal of neurosurgery · Jan 2000
Increased cerebral blood flow but no reversal or prevention of vasospasm in response to L-arginine infusion after subarachnoid hemorrhage.
The reduction in the level of nitric oxide (NO) is a purported mechanism of delayed vasospasm after subarachnoid hemorrhage (SAH). Evidence in support of a causative role for NO includes the disappearance of nitric oxide synthase (NOS) from the adventitia of vessels in spasm, the destruction of NO by hemoglobin released from the clot into the subarachnoid space, and reversal of vasospasm by intracarotid NO. The authors sought to establish whether administration of L-arginine, the substrate of the NO-producing enzyme NOS, would reverse and/or prevent vasospasm in a primate model of SAH. ⋯ Brief intracarotid and continuous intravenous infusion of L-arginine did not influence the incidence or degree of cerebral vasospasm. After SAH, intracarotid infusion of L-arginine markedly increased rCBF in a primate model of SAH. These findings discourage the use of L-arginine as a treatment for vasospasm after SAH.