Neurosurgery
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Comparative Study
Outcome analysis of acoustic neuroma management: a comparison of microsurgery and stereotactic radiosurgery.
Currently, microsurgical resection of acoustic neuromas by an experienced, multidisciplinary team is thought to be the treatment of choice. During the past 20 years stereotactic radiosurgery has been used as an alternative to surgical removal. To compare the results of both microsurgery and stereotactic radiosurgery, we conducted a study of 87 patients with unilateral, previously unoperated acoustic neuromas with an average diameter less than 3 cm treated by the neurosurgical service during 1990 and 1991. ⋯ Hospital length of stay and total management charges were less in the radiosurgical group (P < 0.001). When compared to microsurgical removal, stereotactic radiosurgery proved to be an effective and less costly management strategy of unilateral acoustic neuromas less than 3 cm in diameter. For many acoustic neuroma patients, stereotactic radiosurgery should be offered as an alternative management strategy.
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Long-term evaluation of patients with aneurysms of the internal carotid artery (ICA) treated by intravascular balloon occlusion has not been reported. From 1977 to 1992, 58 patients (age 14 to 81 years) with ICA aneurysms were treated at our institution by this technique. The aneurysms included 40 intracavernous carotid, 5 petrous carotid, 3 cervical carotid, and 10 ophthalmic segment aneurysms. ⋯ Mean follow-up was 76 months (range, 6 months to 15 years). Six patients who developed transient ischemia caused by emboli responded to volume expansion and anticoagulation treatment. Two patients developed a delayed infarction, and one patient developed aneurysm enlargement that required surgical clipping and obliteration. (ABSTRACT TRUNCATED AT 250 WORDS)
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Glossopharyngeal neuralgia is an uncommon cause of facial pain with a relative frequency of 0.2 to 1.3% when compared with trigeminal neuralgia. It is characterized by intermittent, lancinating pain involving the posterior tongue and pharynx, often with radiation to deep ear structures. Since its first description in 1910 by Weisenburg, a variety of destructive procedures have been performed to provide relief in patients whose pain was refractory to medical treatment. ⋯ Long-term follow-up (mean, 48 mo; range, 6-170 mo) reveals excellent results (complete or > 95% reduction in pain without any medication) in 76% of the patients and substantial improvement in an additional 16%. There were two deaths at surgery (5%) both occurring early in the series as the result of hemodynamic lability causing intracranial hemorrhage. Three patients (8%) suffered permanent 9th nerve palsy. (ABSTRACT TRUNCATED AT 250 WORDS)
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Hydrosyringomyelia was produced experimentally by the injection of kaolin into the cisterna magna of the rabbit, and the ultrastructural changes of the spinal cord surrounding the syrinx were investigated 2, 4, and 6 weeks after injection by transmission electron microscopy. The ependyma at the ventral part of the central canal was flat and stretched, whereas, in the dorsal part, it was split, and the syrinx extended through the dorsal median plane in most animals. Extracellular edema was found in the subependymal white matter and in and around the posterior median septum. ⋯ Sometimes, this further remyelination was abortive, especially where the edema was severe. The ultrastructural changes of the neural tissue and their sequences were identical, in most respects, to those of hydrocephalus and noncommunicating syringomyelia. The oligodendrocytic remyelination with ongoing demyelination found in this model has many similarities to those in experimental hydrocephalus.
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Comparative Study
Effects of droperidol, pentobarbital, and ketamine on myogenic transcranial magnetic motor-evoked responses in humans.
Myogenic motor-evoked responses to transcranial magnetic stimulation of the motor cortex (tcmag-MERs) may become clinically useful for the noninvasive assessment of motor pathway conduction during surgery. However, application is hindered because most anesthetic regimens result in severe depression of tcmag-MER amplitudes. As part of our systematic attempts to identify anesthetic agents and supplements suitable for use during tcmag-MER recording, we studied the effect of bolus doses of pentobarbital (1.5 mg/kg), droperidol (0.07 mg/kg), or ketamine (1 mg/kg), administered intravenously, on compound muscle action potentials to transcranial magnetic stimulation in five healthy volunteers. ⋯ Onset latency was unchanged after any drug. These data indicate that tcmag-MERs are moderately depressed after droperidol and pentobarbital but well preserved after ketamine. Ketamine may be a more suitable supplement to opioid/nitrous oxide anesthesia than droperidol or pentobarbital.