Neurosurgery
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Comparative Study
Failed back surgery syndrome: 5-year follow-up after spinal cord stimulator implantation.
Spinal cord stimulation, in use for more than 20 years, has evolved into an easily implemented technique, with percutaneous methods for electrode placement. We have reviewed our experience with this technique in treating "failed back surgery syndrome," and have assessed patient and treatment characteristics as predictors of long-term outcome. A series of 50 patients with failed back surgery syndrome (averaging 3.1 previous operations), who underwent spinal cord stimulator implantation, was interviewed by impartial third parties, at mean follow-up intervals of 2.2 years and 5.0 years. ⋯ Statistical analysis (including univariate and multivariate logistic regression) of patient characteristics as prognostic factors showed significant advantages for female patients and for those with programmable multi-contact implanted devices. These results, in patients with postsurgical lumbar arachnoid and epidural fibrosis and without surgically remediable lesions, compare favorably with the results in two separate series of patients with failed back surgery syndrome, in whom 1) surgical lesions were diagnosed and repeated operation performed; and 2) monoradicular pain syndromes were diagnosed and dorsal root ganglionectomies performed at our institution. This suggests the need for further assessment of selection criteria, critical analysis of treatment outcome, and prospective study of spinal cord stimulation and alternative approaches to failed back surgery syndrome.
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Seventy of 178 patients with acoustic tumors initially were treated conservatively and have been followed up for an average of 26 +/- 2 months. The tumor size was determined by the mean maximum anteroposterior and mediolateral diameters, using computed tomographic or magnetic resonance imaging scans obtained sequentially throughout the follow-up period. The average tumor growth was 1.6 +/- 0.4 mm the 1st year, and 1.9 +/- 1.0 mm the 2nd year (range, -2 to 17 mm/y): 4 tumors showed apparent regression, 28 (40%) had no detectable growth, and 37 (53%) exhibited growth (average, 3.8 +/- 1.2 mm/y). ⋯ This group had a larger initial tumor size (27.0 +/- 3.4 mm vs. 21.3 +/- 0.9 mm, P less than 0.05), and a faster 1-year growth rate (7.9 +/- 2.3 mm/y vs. 1.3 +/- 0.3 mm/y, P less than 0.05) than the 61 patients who did not require surgery. Two patients, however, experienced neurological deterioration that required surgery, even though there was no tumor growth. The high incidence of acoustic tumors with no detectable growth or apparent spontaneous regression must be taken into account when evaluating the indications for surgery and the efficacy of radiotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)
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Thirty-five consecutive adults with Chiari malformation and progressive symptoms underwent surgical treatment at a single institution over a 3-year period. All patients underwent magnetic resonance imaging scan before and after surgery. Images of the craniovertebral junction confirmed tonsillar herniation in all cases and allowed the definition of two anatomically distinct categories of the Chiari malformation in this age group. ⋯ Postoperative reduction in syrinx volume was observed in 11 of the 20 patients with syringomyelia, including all 9 patients with excellent results. Magnetic resonance imaging has allowed a classification of the adult Chiari malformation in adults based on objective anatomic criteria, with clinical and prognostic relevance. The presence of syringomyelia implies a less favorable response to surgical intervention.
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The authors report their experience with low doses (0.007-0.015 mg/kg), moderate doses (0.016-0.025 mg/kg), and high doses (0.026-0.035 mg/kg) of intrathecal morphine for postoperative analgesia after selective dorsal root rhizotomy surgery in 50 children, aged 3 to 12 years. After closure of the dura, a single dose of preservative-free morphine was injected into the subarachnoid space, and patients were assessed for 48 hours for level of comfort and side effects. The three doses of morphine provided equivalent analgesia and similar side effects. ⋯ No patient experienced late respiratory depression or generalized pruritus. The authors conclude that low doses of intrathecal morphine is as effective as moderate or high doses of morphine for reducing pain in the immediate postoperative period. Intrathecal morphine provides excellent analgesia after selective dorsal rhizotomy.
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Case Reports
Intracranial arteriovenous fistula manifesting as progressive neurological deterioration in an infant: case report.
This 1-year-old male infant had been diagnosed with cerebral degenerative disease because he developed psychomotor regression, and brain atrophy was demonstrated on computed tomography. He underwent magnetic resonance imaging, which suggested a cerebrovascular malformation. ⋯ The occlusion of the feeding artery was followed by a satisfactory recovery. The mechanism of the neurological symptoms in this patient is thought to be caused by a steal phenomenon and compression of the brain stem by venous engorgement in the posterior fossa.