We studied the origin and mechanism of spinal cord pulsation in ten dogs in order to elucidate its clinical significance. Under general anesthesia, a 6 cm length of the animals' cervical spinal cord was exposed and the cerebrospinal fluid removed. The amplitude of spinal pulsation was then measured by means of ultrasonography in Mode M. The measurements were made after the spinal cord was cut: (I) on the cranial side; (2) on the cranial as well as caudal side, with the nerve roots and radicular arteries intact; (3) on both sides as in (2), which was then supplemented with the severance of the nerve roots and radicular arteries. It was demonstrated that, while the pulsation amplitude stood at an average of 88.0,um before the surgical treatment, it rose to 455.0,um in (I) and 274.8,um in (2), but dropped to nearly zero in (3). The 5.2-fold increase in pulsation following the cordotomy on the cranial side was attributed to two factors: (1) the increased spinal mobility due to the cordotomy; (2) the elevation of blood pressure. The results of the three different degrees of spinal detachment suggested that spinal pulsation derived mainly from the radicular arteries and that its presence indicated low tonicity in the spinal cord and favorable circulation in the radicular arteries.

Improvement of outcomes represents the most important problem in the treatment of bacterial meningitis. To achieve such improvement, revision of the guidelines for the clinical management of bacterial meningitis in Japan has been carried out, and these revised Japanese guidelines will soon be published. The choice of specific antimicrobial agents for initial treatment in bacterial meningitis is influenced by a number of factors, including patient age, systemic symptoms, and local patterns of bacterial resistance. In the revised Japanese guidelines, antimicrobial agents based on current knowledge of the epidemiology in Japan are recommended. Bacterial meningitis is a medical emergency, and patients with this disease require immediate medical assessment and appropriate treatment. Rapid diagnosis and treatment of bacterial meningitis reduces mortality and neurological sequelae. We describe the revised Japanese guidelines for the clinical management of bacterial meningitis 2014, with a focus on adults.

Our results indicate that allograft of intervertebral discs has clinical potential because it can serve as a dynamic disc spacer for a certain period of time, but its long-term merits and demerits have to be established.

Posterior decompression using intraoperative ultrasonography and ！ he u 】 trasonic osteotome was investigated in 29 patients sufferlng 丘om thoracic myelopathy due to ossification of ljgaments． The lesions in 7 patients were OPLL ． 9 patients had OPLL accompanied with OYL The Iesions in the remaining 亅3were OYL ． The lesions of OPLL in sixteen patients involved 3． 4 vertebral bodies on average (2 to 8) ， and the lesions of OYL in 22 patients involved 3． 7 vertebral bodies on average (2 to l l) ． Twenty seven patients complained of gait dis田 rbance (Frankers C ； 17 patients ， D ； 10 patjenIs) ． The surgical pr edure was as fbllows；first ， ejther wide laminectomy was perf () rmed in the usua ］manner or OYL was resected using an u ］ trasonic osteotome ． After the dura was exposed ， the degree of decompression of the spinal cord from OPLL was evaluated using intraoperative ultrasonography ． In cases where there were insufficient decompression with severe palsy ， circum − spinal decompression was perf () rmed using the posterolateral approach through the lateral and the anterior wall of the spinal cana1 ． The OPLL was resected using the ultrasonic osteotome under intraoperative ultrasonographic observation ． In patients without severe palsy ， posterior stabilization without resection of OPLL was perforrned ， even if the degree of decompression was insufficient ． As a result of intraoperative ultrasonographic evaluation ， 6patients were shown to havc sufficient decompression and lO were shown to have insufficient decompression ． Of the latter 10 cases ， 7were treated with ¢ ircum − spinal decompression and 3 were treated by posterior stabilization． At the dme of the latter fbllow up observation ranging from l years to l L7 years (average 4 、 8 years) ， an the patients were able to walk although 150f them required support ． As regards to complic 飢 ions of surgery ， there was postoperative transient aggravation of palsy in 5 patients and cerebrospinal f］Uid leakage in 2 patients ・ Considerlng the preoperative severity of palsy and 山 e danger of spinal cord 面 uries due to surgery ， the surgical outcomes were satisfactory ． Therefbre ， intraoperative uhrasonography and the way of the ultrasonic osteotome were able to make such operations safer than the usual procedures in these cases ． Key word ： thoracic myelopathy ， ossification of thoracic ligament ， intraoperative ultrasonography ， ultrasonic osteotome Spinal Surgery l3 (3)：281-288 ， 1999