Anterior decompression and fusion for treating ossification of the posterior longitudinal ligament of the cervical spine was performed in 12 patients. The central part of the vertebral body and the ossified area of the posterior longitudinal ligament were removed by means of a microrongeur and an air drill. The defect was filled with a long bone graft taken from the ilium. The operative results were excellent. Marked improvement of radicular and spinal cord signs was seen in all 12 cases. Three vertebral bodies were fused in one case, four in nine cases, and five in two cases. The highest level of fusion was C-2 and the lowest was T-1. It is considered that any ossification of the ligament below the C-2 level can be removed via an anterior approach as long as no more than five vertebral bodies are involved. Spinal computerized tomography was valuable in providing more detailed information about the stenotic spinal canal and the shape of the ossified ligament.

The facial electromyographic response was monitored intraoperatively in 40 patients with hemifacial spasm who were operated on by microvascular decompression of the facial nerve. All 40 patients showed an abnormal facial electromyographic response (lateral spread response) with a latency of about 10 msec after stimulation. The abnormal response resolved before decompression in 22, resolved immediately with decompression in 16, and failed to resolve in two. Of the 38 patients in whom the abnormal response disappeared during surgery, 36 were postoperatively free from hemifacial spasm and two had mild hemifacial spasm. The two patients in whom the lateral spread response did not disappear during surgery showed persistent hemifacial spasm. In conclusion. Disappearance of the lateral spread response during surgery correlated with the absence of hemifacial spasm in the early postoperative period. The prognosis of hemifacial spasm was good in cases in whom the lateral spread response disappeared. Therefore, the authors think that intra-operative facial electromyography is very useful in assessing the efficacy of microvascular decompression and in predicting the prognosis of hemifacial spasm.

The pathogenesis of delayed sequelae of carbon monoxide (CO) exposure is still unknown. We repeatedly examined a 55-year-old woman with the interval form of CO poisoning, using proton magnetic resonance spectroscopy (MRS). When the clinical picture was severe, MRS revealed markedly lowered N-acetyl-aspartate (NAA)/creatine and phosphocreatine (Cr) ratio and slightly increased choline containing compounds (Cho)/Cr ratio. Subsequently, NAA and Cho/Cr ratio tended to return to normal, reflecting clinical improvement. Proton MRS shows the previously unrecognised neuronal activity in CO poisoning and precisely reflects the severity of symptoms. We stress the superiority of proton MRS over the conventional radiological examinations in CO poisoning.

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