Neurosurgery
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Spinal cord stimulation has been reported to relieve ischemic pain and to enhance peripheral circulation. To elucidate the still unknown mechanisms behind these effects, changes in the peripheral blood flow in the skin of the hind paw after stimulation applied to the dorsal column was studied in the normal rat. A substantial flow increase, monitored by laser Doppler technique, was observed in response to stimulation with an intensity comparable to that used clinically in man, recruiting only low-threshold neuronal elements. ⋯ Stimulation failed to produce an increase in blood flow in addition to that produced by guanethidine and hexamethonium, but high-intensity dorsal column or dorsal root stimulation still was effective. The results indicate that spinal mechanisms are essential and that antidromic activation of primary afferent fibers is unlikely to account for the peripheral vasodilatation induced by low-intensity spinal cord stimulation. Our observations suggest a transitory inhibition of sympathetic vasoconstriction as the principal underlying mechanism.
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Biography Historical Article
Kenneth McKenzie, Harvey Cushing, and the early neurosurgical treatment of spasmodic torticollis.
In 1923, Dr. Kenneth McKenzie trained at the Peter Bent Brigham Hospital under Dr. Harvey Cushing. ⋯ The record includes postoperative drawings of the intraoperative field by Dr. Cushing, a sketch by Dr. McKenzie illustrating the postoperative sensory examination, and pre- and postoperative photographs of the patient.
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Seven cases of vein of Galen aneurysms treated by percutaneous transvenous endovascular occlusion of the aneurysmal vein are presented. In one case, the approach was via the femoral vein, and in the other six cases, by the jugular vein. All of the malformations were multipedicular and, additionally, in six of the seven there was an intervening arterial-arterial network between the posterior thalamoperforating arteries and the wall of the venous aneurysm. ⋯ Measurement of intra-aneurysmal pressure during the course of treatment allowed better understanding of the hemodynamics of the lesions, guided the amount of occlusion to be accomplished during each treatment session, and thus may have prevented the phenomenon of normal perfusion pressure breakthrough. The percutaneous transvenous approach offers all the advantages of the transtorcular approach but avoids surgery. Because of our excellent angiographic and clinical results--five complete and two partial occlusions, with favorable outcomes and no major complications--we believe that this technique is better for the treatment of multipedicular vein of Galen aneurysms than transarterial embolization or surgery.