Neurosurgery
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Lesions of the peripheral part of the trigeminal nerve may cause trigeminal neuropathy associated with severe pain. Such pain usually does not respond to carbamazepine and analgesics, and it is continuous and lacks the characteristic paroxysmal character of tic douloureux. These patients often present with complex changes of facial sensibility in the form of dysesthesia, hyperalgesia, and allodynia. ⋯ For the selection of patients for permanent electrode implantation, a method has been developed for trial stimulation via a percutaneous electrode introduced into the trigeminal cistern. Temporary trial stimulation can be performed for several days. It is concluded that stimulation of the trigeminal ganglion and rootlets with the aid of an implanted electrode may effectively relieve certain forms of trigeminal pain that are otherwise extremely difficult to manage.
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The effects on cerebral metabolism and the electroencephalogram (EEG) of combining hypocapnia with hypotension have been only incompletely examined. The present study examined the possibility that hypocapnia may worsen the cerebral metabolic and EEG disturbances caused by hypotension. Cerebral metabolism and the EEG were studied at three levels of hypotension during hypocapnia (PaCO2 = 20 mm Hg) in dogs under light halothane anesthesia. ⋯ Cerebral metabolic values were unchanged at a MAP of 60 mm Hg. At MAP less than or equal to 50 mm Hg, power in the beta 1 spectrum, brain tissue phosphocreatine, and the cerebral energy charge all decreased. At a MAP of 40 mm Hg, the cerebral glucose value decreased and the lactate/pyruvate ratio increased.(ABSTRACT TRUNCATED AT 250 WORDS)
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A 77-year-old man presented with a 4-year history of progressive dysphagia to the point that he could no longer swallow solid foods. During the past several months, he had developed dysphonia. ⋯ Evaluation with barium swallow and cervical computed tomography demonstrated esophageal and laryngeal compression. Resection of the anterior osteophytes resolved the dysphagia and dysphonia.
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Sophisticated techniques for electrical stimulation of excitable tissue to treat neuromuscular disorders rationally have been developed over the past 3 decades. A historical review shows that electricity has been applied to the phrenic nerves to activate the diaphragm for some 200 years. Of the contemporary methods for stimulating the phrenic nerve in cases of ventilatory insufficiency, the authors prefer stimulation of the phrenic nerve in the thorax using a platinum ribbon electrode placed behind the nerve and an attached subcutaneously implanted radiofrequency (RF) receiver inductively coupled to an external RF transmitter. ⋯ Candidates for diaphragm pacing are those with ventilatory insufficiency due to malfunction of the respiratory control center or interruption of the upper motor neurons of the phrenic nerve. In the Yale series, there were 77 patients treated by diaphragm pacing; 63 (82%) started before 1981 and thus were available for follow-up for at least 5 years; 33 (52%) were paced for 5 to 10 years, and 15 (24%) were paced for 10 to 16. Long term stimulation of the phrenic nerves to pace the diaphragm is an effective method of ventilatory support in selected cases.
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Quantitative measurements of the epidural space between T-7 and L-4 were made in the sagittal and coronal planes utilizing x-ray films made after the injection of iodized oil into the epidural space in the low thoracic and upper lumbar areas. These data reveal a 1-mm ventral epidural space and a 2-mm lateral epidural space, with a sawtooth shape to the dorsal epidural space measuring between 1.1 and 2.9 mm at the rostral lamina and between 3.8 and 6.5 mm at the caudal lamina. Additionally, five patients with chronic pain were studied by computed tomography of T-8 to T-12, with confirmation of the sawtooth shape of the dorsal epidural space. Computed tomography showed the measurements of the epidural space at the rostral lamina to vary between 1.3 and 1.6 mm and those at the caudal lamina/interlaminar space to range from 6.9 to 9.1 mm.