Journal of neurosurgery
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Journal of neurosurgery · Feb 1996
Case ReportsIntrathecal granuloma complicating chronic spinal infusion of morphine. Report of three cases.
Intrathecal morphine delivered by implanted pumps has been used in the treatment of pain caused by terminal cancer. Some authors supports its use in benign pain as well. The authors present three cases in which chronic infiltration of intraspinal narcotic medication was complicated by the formation of a granulomatous mass that became large enough to exert mass effect and induce neurological dysfunction.
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Journal of neurosurgery · Feb 1996
Effects of spinal cord stimulation on the flexor reflex and involvement of supraspinal mechanisms: an experimental study in mononeuropathic rats.
The physiological mechanisms responsible for pain relief caused by spinal cord stimulation (SCS) are essentially unknown and recent experimental data are sparse. In the present study the authors explored the possible involvement of supraspinal mechanisms in the effects of SCS applied in rats with experimental mononeuropathy produced by sciatic nerve ligation according to the method of Bennett and Xie or that of Seltzer, et al. Confirming results of a previous study undertaken by the authors, the thresholds of the early component of the flexor reflex (latency 8-12 msec), which is mediated by A fibers, were significantly lower in the nerve-ligated than in the intact leg. ⋯ There was no effect on the late component of the reflex in either leg. The results indicate that this effect of SCS in mononeuropathic rats does not necessarily involve supraspinal mechanisms; instead SCS is operative at a spinal, segmental level. In view of the similarities between the effects of therapeutic SCS on cutaneous hypersensibility in patients with peripheral neuropathic pain and the effects demonstrated in neuropathic rats, the clinical pain relief achieved with SCS may be produced, at least partially, by intraspinal mechanisms.
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Journal of neurosurgery · Feb 1996
Randomized Controlled Trial Multicenter Study Clinical TrialRandomized, double-blind, vehicle-controlled trial of tirilazad mesylate in patients with aneurysmal subarachnoid hemorrhage: a cooperative study in Europe, Australia, and New Zealand.
Tirilazad mesylate, a nonglucocorticoid 21-aminosteroid, has been shown in experimental models to reduce vasospasm following subarachnoid hemorrhage (SAH) and to reduce infarct size from focal cerebral ischemia. To test whether treatment with tirilazad would reduce ischemic symptoms from vasospasm and improve overall outcome in patients with ruptured aneurysms, a prospective randomized, double-blind, vehicle-controlled trial was conducted at 41 neurosurgical centers in Europe, Australia, and New Zealand. One thousand twenty-three patients were randomly assigned to receive 0.6, 2, or 6 mg/kg per day of intravenously administered tirilazad or a placebo containing the citrate vehicle. ⋯ There were no material differences between the outcomes in the groups treated with 0.6 and 2 mg/kg tirilazad per day and the group treated with vehicle. Tirilazad was well tolerated at all three dose levels. These observations suggest that tirilazad mesylate, at a dosage of 6 mg/kg per day, is safe and improves overall outcome in patients (especially in men) who have experienced an aneurysmal SAH.
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Journal of neurosurgery · Feb 1996
Case ReportsOncogenic osteomalacia associated with a meningeal phosphaturic mesenchymal tumor. Case report.
A 60-year-old woman suffered from hypophosphatemic osteomalacia secondary to a frontal intracranial tumor. Oral administration of phosphate and 1-alpha-hydroxyvitamin D3 provided only temporary symptomatic relief. A computerized tomography (CT) scan of the patient's head revealed a large subfrontal tumor attached to the dura. ⋯ Three years later, decreasing levels of phosphate and 1,25-dihydroxyvitamin D3 indicated tumor recurrence, before it was detected by CT scan. Histological examination of the tumor provided the diagnosis of "mixed connective tissue variant of phosphaturic mesenchymal tumor." The characteristic histological features of this relatively rare entity are discussed. This is the first report of a surgically treated intracranial phosphaturic mesenchymal tumor that caused oncogenic osteomalacia.
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Journal of neurosurgery · Feb 1996
Microvascular anatomy of dural arteriovenous abnormalities of the spine: a microangiographic study.
Although most vascular abnormalities of the spinal cord are now ascribed to an abnormal communication between a dural artery and a medullary vein on the dura near a sensory nerve root, these lesions are too small for their anatomy to be demonstrated directly by spinal arteriography. Thus, it is unknown whether the site of dural arteriovenous shunting is an arteriovenous malformation (AVM), implying a congenital origin, or is a direct arteriovenous fistula (AVF), implying an acquired etiology. The authors treated six patients by en bloc resection of the involved dural root sleeve, proximal nerve root, and adjacent spinal dura. ⋯ Several medium-to-small collateral vessels arising from adjacent intercostal or lumbar arteries were commonly present in the dura and converged at the site of the AVF to join a single medullary vein. These results show that spinal dural AVMs are direct AVFs that link the dural branch of the radiculo-medullary-dural artery with the intradural medullary vein. They also provide an anatomical explanation for the presence of a multiple segmental arterial supply and a single draining medullary vein of spinal dural AVFs, and the propensity for reestablishment of flow through the arteriovenous shunt after embolic occlusion.