I would like to discuss some thoughts and a few clinical observations on the interactions between the brain and spinal cord. First, regarding whether a neurological symptom is caused by the brain or spinal cord disorder, a case of acute-onset unilateral shoulder paresis is introduced. Although shoulder paresis has been recognized as an orthopedic problem and most cases of upper limb pure motor monoparesis due to cortical infarction present with hand weakness, My colleagues and I reported, first in the world, a case of isolated shoulder paresis due to a small infarction located medial and posterior to the precentral knob.

  Secondly, regarding how the brain disorder influences the spinal cord, a case showing neurological deterioration three years after C3-C7 laminectomy for OPLL and a half year after endovascular operation for left cavenous sinus dural arteriovenous fistula is introduced. MRIs of this case revealed severe edema and venous congestion from the medulla oblongata to the upper cervical cord which disappeared by the second endovascular operation at the skull base.

  Thirdly, regarding how the spinal cord disorder influences the brain, a case of convulsion four years after cervical anterior decompression for cervical injury and a case of normal pressure hydrocephalus owing to cauda equina neurinoma are introduced. The former was due to autonomic hyperreflexia and the latter might be caused by the increase in CSF protein.

  Fourthly, regarding the transition zone between the brain and the spinal cord, a case of C3/4 disk herniation presenting with facial pain of cape-like pattern and a case of hypoglossal nerve palsy due to skull base metastasis of adenocarcinoma of unknown origin are introduced. Both tell us the importance of the anatomical knowledge of the cervicomedullary junction.

  Finally, regarding disorders involving both the brain and spinal cord, a case of aquaporin-4-antibody-positive neuromyelitis optica (NMO) showing intractable hiccup and dorsal medulla lesion on MRI is introduced. Although NMO has traditionally been regarded as a disease without brain involvement, patients with NMO are frequently found to have symptomatic or asymptomatic brain lesions which characteristically involve the medulla oblongata, hypothalamus, periventricular areas, or the cortex or subcortex with multiple “cloud-like enhancement”.

  In conclusion, to borrow Karl Marx's famous phrase “Human anatomy contains a key to the anatomy of the ape”, I would like to say to spinal surgeons, “Brain symptomatology contains a key to the symptomatology of the spinal cord.

  Object : Intramedullary hemangioblastomas are relatively rare neoplasms, resection of which is difficult because of abundant blood supply. In this paper, cases of intramedullary hemangioblastomas, and our technique of resection are described.

  Patients and Methods : During the period from 1998 to 2011, a total of 14 intramedullary hemangioblastomas in 12 patients were surgically resected by one author. Our series included 5 females and 7 males (mean age of 51 years).

  Results : All tumors were exposed on the surface of the spinal cord and the total resection of the tumor was accomplished in 11 patients. In one case in the early period, debulking of the tumor without identification of the boundary resulted in excessive bleeding, and neurological deterioration. This was due to a lack of knowledge that the boundery of a hemangioblastoma is covered by opaque and thickened pia mater. After recognizing this property, which was confirmed in 8 patients in this series, the boundary was exposed by sharp dissection of pia mater before resecting the tumor. In addition, feeding arteries were occluded before resection for reducing the volume and tension, thus making the resection easy. However, identification of feeding arteries may be difficult during surgery because of the strong similarity of the color with the draining veins. ICG fluorescence videography may be useful for this respect. Neurological status improved in 8 cases and worsened in 1 case after surgery.

  Conclusion : Occlusion of feeding arteries and sharp dissection of pia mater covering the border of a tumor is important for a total en-block resection of spinal cord hemangioblastomas.

  Introduction : Symptoms, diagnosis, and treatments for lumbar radiculopathy due to lumbar intervertebral extraforaminal lesions has often been discussed in recent years. This pathology is by no means a rare condition. We report the treatment of this condition at our institute.

  Materials and Methods : At our institution, lumbar radiculopathy due to extraforaminal lesions is diagnosed on the basis of neurological findings and confirmed by neuroradiological imagings methods such as magnetic resonance imaging (MRI) and computed tomography (CT). Recently, radiculography and nerve root blocks are not necessarily performed for the management of lumbar radiculopathy. From 2005 to 2010, 21 patients underwent surgery. These patients included 10 patients with far-out syndrome (FOS), 8 with extraforaminal disc herniation, and 3 with extraforaminal tumors.

  Results : Revision surgery was performed in 6 cases : 4 cases of extraforaminal disc herniation and 2 cases of FOS. Identification of FOS tended to be delayed. In cases of extraforaminal lesions in which insufficient nerve-root decompression was achieved by the first operation, reoperation was performed for appropriate and adequate nerve-root decompression. Transforaminal lumbar interbody fusion (TLIF) methods were performed in a case of FOS, 2 cases of extraforaminal disc herniation, and 1 case of extraforaminal ganglion cyst ; however, in the other cases, only nerve-root decompression was performed by surgery through the Wiltse paraspinal approach.

  Discussion and Conclusion : In recent times, diagnosis of extraforaminal lesions has become easier because of advancements in MRI. Magnetic resonance neurography enables direct visualization of nerve root edema and root compression itself. Extraforaminal disc herniation can be managed by surgically removing the herniated disc via the Wiltse paraspinal approach. Since aggressive nerve-root decompression is required in cases of lumbar canal stenosis complicated by intra-and extra-foraminal lesions, we consider TLIF as the primary procedure in cases with advanced deformities.

  Objective : To discuss motor-evoked potential (MEP) monitoring of decompression in spinal surgeries, particularly surgeries for compressive spinal and radicular disorders, by using transcranial MEP.

  Methods : MEP monitoring after transcranial stimulation was performed during 148 spinal surgeries. MEP monitoring was performed using 200- to 600-V transcranial stimulations, and electromyograms were recorded. MEP amplitudes were compensated by compound muscle action potential (CMAP) after peripheral nerve stimulation. Among 148 patients, 134 had no preoperative motor palsy and 122 had been operated on for the decompression of compressive spinal and radicular disorders.

  Results : In the 134 patients without preoperative motor palsy, the sensitivity of MEP monitoring in spinal surgery was 100% both with or without CMAP compensation, according to the criterion of 80% amplitude reduction as described by Langeloo, et al. The specificity in these 134 patients was 95.2% with CMAP compensation and 94.4% without CMAP compensation, according to the same criterion. In the 122 patients who underwent surgeries for spinal and radicular compressive disorders, the mean relative amplitude after CMAP compensation in the excellent (E) postoperative result group (recovery rate of Japan Orthopedic Association score more than 50%) was significantly higher than that in the other groups (p=0.0015). The number of patients in the E group whose relative amplitude index compensated by CMAP more than 1.0 was significantly higher than that less than 1.0 (p=0.0003). All patients whose relative amplitude index with CMAP compensation was more than 1.2 achieved postoperative neurological recovery.

  Conclusion : Intraoperative MEP monitoring in spinal surgery was highly sensitive because none of the patients had false-negative results during more than 100 surgeries. If the relative amplitude index with CMAP compensation after peripheral nerve stimulation was more than 1.2, neurological recovery could certainly be expected. MEP in spinal surgery is very useful because of not only its high sensitivity and specificity but also the possibility for monitoring neurological recovery with CMAP compensation.

  Background : Since 2001, we have consistently used a box-shaped titanium cage for anterior cervical fixation, with good treatment outcomes. Some studies, however, have recommended that the facile use of titanium cages should be reserved because long-term outcomes from the use of man-made objects are unclear. We herein report on the long-term outcome of this surgical method based on 10-years experience of using titanium cages and the accumulation of patients who have undergone long-term observation.

  Materials and methods : A radiological study was conducted on 48 cases for which it was possible to take cervical photographs for a period of 2 years or more following surgery. The profiles of the cervical X-ray prior to surgery, directly following surgery, and at 2 years following surgery were input into a computer, and sinking, changes in local alignment, and the rate of bone fusion were measured. Furthermore, for 87 cases in which follow-up on an outpatient basis or by phone was possible, the occurrence of new neurologic symptoms or other complications after discharge was investigated.

  Results : The radiological study confirmed that no changes in the local vertebral height or alignment were observed throughout the 44.2±19.8 months following surgery. The rate of bone fusion was 94.5%, which is not inferior to that reported previously. Furthermore, the only cases in which new neurologic symptoms had developed in the 2 years following surgery were 5 cases due to adjacent intervertebral disorder. No long-term complications peculiar to the cage were observed throughout the 69.8±33.7 months following surgery.

  Conclusion : A good long-term outcome of anterior cervical fixation using a titanium cage was confirmed.

  Here, we report cases of 6 patients with ulnar neuropathy at the wrist (UNW). The patients included 3 women and 3 men with ages ranging from 30 to 56 years.

  On the basis of the patients' symptoms, we made a diagnosis of type Ⅰ UN (a mixed motor and sensory neuropathy) in 2 patients and of type Ⅳ UN (a pure motor neuropathy with sparing of hypothenar muscles) in the remaining 4 patients by using Wu's classification (1985). Surgery was performed for all patients, and the site of the compression and cause were confirmed. The ulnar nerve was compressed by the engorged vein of the arteriovenous fistula, anomalous muscle (large palmaris brevis muscle), aponeurosis of the hypothenar muscles at the pisohamate hiatus, and ganglion in 1, 1, 2, and 2 patients, respectively. Neurophysiological examination revealed distal latency to the hypothenar muscle to be normal in the patients with type Ⅳ UNW but that to the first dorsal interosseous muscle to be markedly prolonged in all cases. Although the reason why the hypothenar muscles were spared in these cases is still unclear, it might be the same as that underlying the fascicular phenomenon observed in cases of ulnar neuropathy at the elbow. Except for the results obtained for 2 patients with a long history of UNW before the operation, excellent results were obtained in the remaining patients.

  In conclusion, we would like to emphasize that, although signs and symptoms of UNW may vary according to the compression site and underlying causes, early diagnosis and surgical treatment may lead to favorable results.

  For the management of large cervical dumbbell-shaped neurinomas, generally, a posterior approach is first employed for the removal of the intraspinal tumor, and removal of the remaining extraspinal tumor is attempted through an anterior approach. However, several anterolateral approaches have attempted to remove some cervical dumbbell-shaped neurinomas by one-stage operation. These approaches are excellently organized to remove intraspinal portion of the tumors as well as extraspinal portion via the route medial to the sternocleidmastoid muscle (SCM).

  We report our experience of 2 cases in which large cervical dumbbell-shaped neurinomas laterally extended between the anterior and middle scalenus muscle to the external jugular vein. We performed surgery through a retro-SCM approach to remove the laterally extending tumors. For safe handling of vertebral arteries, we also used the pre-SCM route to expose the anterior tubercles of the transverse process. The retro-SCM approach along the extension of the tumors provided an excellent surgical corridor for the removal of extraspinal, intraforaminal, and even intraspinal portions of the tumor. Moreover, no obstacle, except for the supraclavicular nerve just on the surface of the tumor, was encountered. We were able to preserve this nerve without intense effort. Although 1 patient complained of transient dysesthesia over the ipsilateral clavicular region after the operation, the other patient had no complaints.

  We believe that this approach is safe and effective for the removal of large cervical dumbbell-shaped neurinomas with lateral extension ; however, the approach needs to be investigated in more cases in the near future.

  Objective : Fondaparinux, a factor Ⅹa inhibitor and thromboprophylactic drug, has been used increasingly since its approval in Japan. We report a rare case of spinal subarachnoid hemorrhage thought to be associated with Fondaparinux and discuss its treatment with a review of the literature.

  Clinical presentation : A 75-year-old woman who received subcutaneous injection of fondaparinux daily after gynecologic surgery presented with progressive weakness in both legs with bladder and rectal disturbance. The procedure was done under general anesthesia, without use of lumbar puncture. MRI and CT revealed intradural hematoma extensively compressing the spinal cord.

  Intervention : An emergency operation was performed to evacuate the hematoma. Opening of the dura revealed a massive subarachnoid hematoma, covering the neural structures completely. After gentle evacuation of the hematoma, we found no vascular abnormalities and concluded that the hemorrhage had been caused by the drug.

  Postoperative course : The patient exhibited improvement in symptoms and was discharged from the hospital on her feet with a T-cane after 2 months of rehabilitation. One month after discharge, her only symptom was numbness in the left leg and she needed no support, although MRI revealed an intradural arachnoid cyst.

  Consideration : Fondaparinux is reported to be safe and effective in preventing postoperative venous thromboembolism, but cannot be without the increased risk of bleeding. Although spinal subarachnoid hemorrhage associated with fondaparinux is extremely rare, spine surgeons should be aware about the risk. Prompt diagnosis and proper measures, are necessary when the patient's neurological status deteriorates.

  Conclusion : Patients receiving fondaparinux treatment should be monitored closely for neurological sequella even if a lumbar puncture is not performed.

  We report our surgical experiences with two cases of gas-containing discal cyst. From January 2008 to December 2010, we have surgically treated 574 patients with spinal disorders, of which 309 were with lumbar degenerative disease. Out of 309 cases, 2 patients had gas-containing discal cyst. The first patient had multi-level spinal canal stenosis in the lumbar spine, and posterior decompression by the midline approach (splitting the spinous process) was carried out. A bubble-like cystic mass was removed at the L5-S1 level. The other patient had bilateral L5 isthmic spondylolysis, and a tubular retractor was used to remove the bubble-like cystic mass at the L5 level. Both patients resumed their daily activities within a few days after the operation. Histopathological studies of the excised cyst showed multi-cystic lesion surrounded by hyaline cartilage and fibrous tissue. The cyst contained mucosal material cartilage tissue. The latter reacted positive with S-100 protein, a hallmark for intervertebral disc. Since we did not perform intradiscal maneuver in these patients, the present gas-containing cysts are considered to be derived from intervertebral disc. Microsurgical removal of the cyst is recommended for satisfactory surgical results. Preoperative evaluation with computed tomography (CT) is mandatory for accurate diagnosis of the gas-containing discal cyst.