Peripheral nerve hemangioblastoma.

Capillary hemangioblastoma (HB) is a benign, highly vascular tumor limited almost exclusively to the central nervous system (CNS). It occurs primarily in the posterior fossa and less often in the spinal cord. We report three cases of HB occurring in peripheral nerve, two intradural tumors arising in a C4 and a cauda equina nerve root, respectively, and a third lesion in the sciatic nerve at mid thigh. The patients, 1 woman and 2 men, ranged in age from 25 to 49 years. Two had von Hippel-Lindau disease, an association usually found in one-third of CNS HBs, and one had a family history of pheochromocytoma. In every way, HBs of peripheral nerve were indistinguishable from their CNS counterpart. Ranging in size from 1.5 to 5.5 cm in diameter, the tumors were well circumscribed and contained a myriad of small caliber vessels lined by endothelial cells and surrounded by pericytes. Throughout, the lesions were rich in large, often vacuolated stromal cells. In all of the cases, these stained strongly for vimentin and neuron-specific enolase; only one showed focal S100 protein reactivity. Surgical therapy required excision of the affected nerve roots in the first two cases. In the third case, prominent extension of the tumor within epineurium permitted a microsurgical resection with sparing of sciatic nerve fascicles. No tumor recurred during a follow-up period of 5 to 20 months.

Indications for fusion following decompression for lumbar spinal stenosis.

Degenerative lumbar spinal stenosis is a common condition affecting middle-aged and elderly people. Significant controversy exists concerning the appropriate indications for fusion following decompressive surgery. The purpose of this report is to compare the clinical outcomes of patients who were and were not treated with fusion following decompressive laminectomy for spinal stenosis and to identify whether fusion was beneficial. The authors conclude that patients in whom concomitant fusion procedures were performed fared better than patients who were treated by means of decompression alone when evidence of radiological instability existed preoperatively.

Clinical outcomes and radiological instability following decompressive lumbar laminectomy for degenerative spinal stenosis: a comparison of patients undergoing concomitant arthrodesis versus decompression alone.

One hundred twenty-four patients with degenerative lumbar stenosis underwent decompression with fusion (32 patients) and without fusion (92 patients) during a 30-month period between 1986 and 1988. Patient-reported satisfaction at a mean follow-up period of 5.8 years (range 4.6-6.8 years) revealed a 79% good or fair outcome and a 21% poor outcome (26 patients). Seven patients (6%) developed lumbar instability, three patients (2%) developed new stenosis at an adjacent unoperated level, and three patients (2%) developed a new disc herniation between 2 and 5 years after surgery. Progressive postoperative spondylolisthesis occurred in 31% of patients with normal preoperative alignment (mean 7.8 mm, range 2-20 mm) and in 73% of patients with preoperative subluxation (mean 5.1 mm, range 2-13 mm) in whom fusion was not attained. Radiological progression did not correlate well with patient-reported outcome. The major conclusions from this study are the following: 1) the majority of patients respond well to this surgery, but complication (22%) and late deterioration (10%) rates are not insignificant; 2) radiological instability is common after decompression for degenerative lumbar spinal stenosis, but this correlates poorly with clinical outcome; 3) there are no definitive clinical or radiological factors that preoperatively predict patients at risk for a poor outcome; 4) post-operative radiological instability is more likely to occur when the following criteria are present: preoperative spondy-degenerated L-4 or a markedly degenerated L-3 disc; and when a radical and extensive decompression greater than one level is planned; and 5) the group at greatest risk for a poor outcome consists of those patients with normal preoperative alignment who do not suffer slippage following surgery.

Anterolateral decompression of the atlantoaxial vertebral artery for symptomatic positional occlusion of the vertebral artery. Case report.

A case of repeated vertebrobasilar ischemic attacks related to head rotation (bow hunter's stroke) is reported. With head rotation of 45 degrees or more to the right, the patient would become lightheaded and feel as if she were going to lose consciousness. Angiography performed when head rotation was to the right revealed mechanical compression of the left vertebral artery at the foramen transversarium of the axis and an occluded right vertebral artery. Untethering of the vertebral artery as it passed through the foramen transversarium of the atlas in this case completely relieved the patient's symptoms. The authors conclude that contralateral vertebral artery occlusion predisposed this patient to symptomatic vertebrobasilar insufficiency secondary to ipsilateral vertebral artery mechanical stenosis induced by head turning.

Transdural approach to the anterior spinal canal in patients with cervical spondylotic myelopathy and superimposed central soft disc herniation.

We present seven patients with multilevel cervical spondylotic myelopathy and superimposed midline soft disc herniation who were treated by decompressive laminectomies of the spondylotic segments followed by transdural excision of the anteriorly located disc extrusion. There was no perioperative neurological morbidity or mortality associated with this operation, and no patients have developed postoperative kyphotic deformity with an average follow-up of 50.1 months (range, 24 to 87 mo). Two patients had full neurological recovery, whereas five patients had improvement in their preoperative neurological status. We conclude that a posterior transdural approach may offer an alternative surgical option for select patients with multilevel cervical spondylosis with superimposed midline soft disc herniation in whom multiple segment decompression plus access to the anterior spinal canal is necessary.

Neuroprotection by corticotropin releasing factor during hypoxia in rat brain.

BACKGROUND AND PURPOSE: Corticotropin releasing factor is an endogenous neuropeptide released by the hypothalamus that activates the pituitary-adrenocortical system in response to stressful stimuli. It has been demonstrated that corticotropin releasing factor increases the excitability of hippocampal neurons in both in vitro and in vivo studies, which may contribute to neurological injury during hypoxia. The purpose of this study was to determine the effects of corticotropin releasing factor and its synthetic competitive antagonist, alpha-CRF, on neuronal synaptic recovery after a hypoxic insult using the hippocampal slice. METHODS: Wistar rat hippocampal brain slices (n = 120) were treated with various concentrations (10(-6) to 10(-11)) of corticotropin releasing factor or its synthetic antagonist during a 10-minute hypoxic episode. Extracellular recording of population spikes was used during and after the hypoxic insult to assess neuronal recovery. RESULTS: Corticotropin releasing factor provided dose-dependent neuronal protection with maximum recovery (37.95 +/- 8.71%) occurring at 10(-9) concentrations. The competitive antagonist alpha-CRF provided a similar degree of recovery at 10(-6) concentration, whereas 10(-9) molar concentration of competitive antagonist resulted in 16.84 +/- 7.68% recovery. CONCLUSIONS: Corticotropin releasing factor provides moderate protection to hypoxic hippocampal neurons in the brain slice preparation. The mechanism of action is unknown but appears to be a direct neuronal effect. These results support the hypothesis that corticotropin releasing factor may act as an endogenous neuroprotective hormone during hypoxia.

Neurological complications of ankylosing spondylitis.

Thirty-three patients with ankylosing spondylitis with or without spinal neurological symptoms requiring surgical intervention were identified in a retrospective review of all cases of spinal disorders treated at the Mayo Clinic during the period from 1984 to 1989. Spinal fractures (traumatic or pseudoarthroses), progressive spinal deformity, rotary instability secondary to atlanto-occipital or atlantoaxial subluxation, and spinal stenosis with associated neurological deficit, pain, or spinal instability were the most common indications for surgery. Of the 41 operations performed, there were 17 cervical, 14 thoracic, and 10 lumbar procedures. Eight patients had two or more disorders at separate spinal levels that required surgery. Preoperative neurological deficits were recorded in 13 patients; these improved following surgery in nine and stabilized in four. This review emphasizes the fragility of the ankylosed spinal column and its inherent susceptibility to fracture with attendant neurological compromise. It also identifies the variety of spinal disorders observed in these patients and discusses their surgical management. The experience with this series suggests that thorough radiological evaluation, extreme caution with endotracheal intubation and with halo-vest applications, early surgical spinal immobilization, and aggressive postoperative mobilization of patients are necessary for a successful outcome. It is concluded that outcomes in these patients can be favorable when managed appropriately.