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Posterior stabilization is a common surgical procedure, which aims for rigid stabilization by facet fusion. Facet non-union has a potential risk of the screw loosening and malalignment. Although some authors have reported the influencing factors about screw loosening in the lumbar spine, there are few reports about the risk factor contributing to the facet non-union in the cervical spine. In all, 22 patients (78 facets and 122 screws) with degenerative cervical kyphosis or spondylolisthesis who underwent decompression and lateral mass screw (LMS) fixation were analyzed. Age, gender, smoking, bone mineral density (BMD), the degree of facet decortication with bone packing, and screw loosening were investigated as risk factors contributing to the facet non-union at each segmental fused level. Facet fusion rate was 85.9% (67/78 facets) and the incidence of loosening was 4.9% (6/122 screws, 4 patients). Insufficient facet decortication with bone packing is a significant risk factor of facet non-union (p

Background The prevalence of osteoporotic vertebral compression fracture (OVCF) is increasing. The indications for and efficacy of balloon kyphoplasty (BKP) are controversial. We sought to identify predictors of outcome after BKP in patients with OVCF. Methods Between January 2001 and December 2019, 152 patients underwent BKP for painful OVCFs at our institution. This study included 115 patients who were followed for >12 months, and their data were retrospectively analyzed. With regard to the degree of independent living 1 year after BKP, patients were divided into a good outcome group (composed of patients who could independently go indoors) and a poor outcome group. We analyzed factors associated with outcome and subsequent OVCF. Results Mean age of patients was 77.9 years, 58.2% were female, 81% had a good outcome, and 19% had a poor outcome. Univariable analysis revealed significant differences in age, bone mineral density, preoperative vertebral body decompression rate, body mass index (BMI), preoperative Japanese Orthopaedic Association score, preoperative modified Rankin Scale score, and subsequent OVCF. Multivariable logistic analysis showed that low BMI (odds ratio 1.415, 95% confidence interval 1.06–1.87, P = 0.046) and subsequent OVCF (odds ratio 0.13, 95% confidence interval 0.02–0.69, P = 0.044) were independent risk factors. The incidence of subsequent OVCF was also lower among patients with higher BMI (odds ratio 0.83, 95% confidence interval 0.72–0.95, P = 0.001). Conclusions BMI and subsequent OVCF are the most influential predictors of independent living 1 year after BKP for OVCF.

OBJECTIVESurgical management of thoracic ossification of the posterior longitudinal ligament (OPLL) remains challenging because of the anatomical complexity of the thoracic spine and the fragility of the thoracic spinal cord. Several surgical approaches have been described, but it remains unclear which of these is the most effective. The present study describes the microsurgical removal of OPLL in the middle thoracic level via the transthoracic anterolateral approach without spinal fusion, including the surgical outcome and operative tips.METHODSBetween 2002 and 2017, a total of 8 patients with thoracic myelopathy due to OPLL were surgically treated via the transthoracic anterolateral approach without spinal fusion. The surgical techniques are described in detail. Clinical outcome, surgical complications, and the pre- and postoperative thoracic kyphotic angle were assessed.RESULTSThe mean patient age at the time of surgery was 55 years (range 47–77 years). There were 5 women and 3 men. The surgically treated levels were within T3–9. The clinical symptoms and Japanese Orthopaedic Association (JOA) score improved postoperatively in 7 cases, but did not change in 1 case. The mean JOA score increased from 6.4 preoperatively to 7.5 postoperatively (recovery rate 26%). Intraoperative CSF leakage occurred in 4 cases, and was successfully treated with fibrin glue sealing and spinal drainage. The mean follow-up period was 82.6 months (range 15.3–169 months). None of the patients had deterioration of the thoracic kyphotic angle.CONCLUSIONSAnterior decompression is the logical and ideal procedure to treat thoracic myelopathy caused by OPLL on the concave side of the spinal cord; however, this procedure is technically demanding. Microsurgery via the transthoracic anterolateral approach enables direct visualization of the thoracic ventral ossified lesion. The use of microscopic procedures might negate the need for bone grafting or spinal instrumentation.

Background Formation of a dural arteriovenous fistula (DAVF) after lumbar spine decompression in the lumbar spine has been reported as a late complication, but is extremely rare in the cervical spine. Case Description A 57-year-old man who underwent a C5-6, C6-7 anterior fusion 5 years previously for cervical myelopathy at another hospital presented with progressive gait disturbance and thermal hypoalgesia on the right side of the body. Magnetic resonance imaging showed flow voids in the spinal cord dorsally at the C4-7 level, which had not been detected before the initial operation. Digital subtraction angiography showed a fistulous connection at the C7 level between the perimedullary vein and a segmental artery from the right vertebral artery, which was diagnosed as a DAVF. Surgical interruption of the intradural draining vein with multilevel posterior cervical decompression was performed, and his symptoms improved. Conclusions To the best of our knowledge, this is the first report of a DAVF developing after multilevel anterior cervical discectomy and fusion. All the published cases of secondary DAVF, especially after spinal surgery, are reviewed.

Background Ventral lesions of upper thoracic spinal cord due to degenerative diseases are rare and often have poor operative outcomes. Anterior decompression of the lesion is difficult because of the local anatomy. This retrospective study aimed to evaluate reproducible anatomic measurements for selecting the best surgical approach for anterior decompression of ventral lesions of upper thoracic spinal cord. Methods Cases of anterior decompression of ventral lesions of upper thoracic spinal cord due to degenerative diseases at our institution from 2004 to 2015 were assessed. Several lines were drawn on magnetic resonance imaging and computed tomography scans of midsagittal sections of the upper thoracic spine to evaluate the most optimal approach for treating upper thoracic lesions. A line from the suprasternal notch to the vertebral body (suprasternal notch to vertebral body [SV] line) was accepted as baseline. Results The caudal edge of the lesion was above the SV line in 10 cases, each of which was treated via an anterior approach without sternotomy. The caudal edge was below the SV line in 7 cases, 5 of which underwent surgery with the sternum-splitting or transthoracic approach. The other 2 lesions were approached via an obliquely deviated route without sternotomy. The SV line sometimes changed with patients' posture alterations. Conclusions The SV line, a useful landmark for upper thoracic lesions, is not sufficiently reliable because it changes according to the patient's posture. By leaning in the direction of the surgical microscope, more caudal upper thoracic lesions can be reached than when using the SV line as a surgical landmark.

Lumbar epidural lipomatosis is a rare condition defined as the excessive accumulation of epidural fat (EF). We herein investigated the indicators of the posterior compression factors, EF and yellow ligament, to identify the clinical features of lumbar epidural lipomatosis.Five hundred consecutive patients who underwent posterior lumbar decompression surgery for lumbar spinal stenosis (LSS) were retrospectively reviewed. The EF/SC-L index (the ratio of the anteroposterior length of the EF to that of the spinal canal [SC]) was evaluated at the spinal level that exhibited maximum dural tube compression. The participants were divided into 3 groups: grade I, EF/SC-L index ≤50%; grade II, EF/SC-L index 51%-74%; grade III, EF/SC-L index ≥75%. EF/SC-A (the ratio of the cross-sectional area of EF to that of SC) and YL/SC-A (the ratio of the cross-sectional area of yellow ligament [YL] to that of SC) were calculated. The clinical outcomes were assessed according to the Japan Orthopaedic Association scale for lumbar disease.EF/SC-L exhibited a significantly positive correlation with EF/SC-A (r = 0.82, P0.001), and a negative correlation with YL/SC-A (r = -0.71, P0.001). The Japan Orthopaedic Association score recovery rate was 56.7 ± 22.6 in the case-matched control group, 34.5 ± 31.2 in the grade II group (P0.001), and 39.6 ± 24.9 in the grade III group (P = 0.032).The EF/SC-L index is a simple and reliable indicator to quantitatively evaluate posterior compression in patients with LSS. As the accumulation of EF is associated with worse operative outcomes, the EF/SC-L index should be considered when planning lumbar decompression surgery for patients with LSS.

Background Spinal epidural hematoma (SEH) is a potentially devastating problem that requires rapid diagnosis and surgical intervention. A chronic course is rarely seen following SEH, and the clinical characteristics are quite different from acute cases. The epidemiology, clinical history, and radiologic findings of chronic SEH (CSEH) are not well understood, although the detection rate has increased with the widespread use of magnetic resonance imaging. The purpose of this article was to report 4 cases of surgically confirmed CSEH and clarify the radiologic features and clinical scenarios by reviewing all published cases of CSEH. Case Description All 4 patients presented with gradually worsening radicular pain in the lower extremities. Patients’ mean age was 69.5 years (range, 55–85 years). Magnetic resonance imaging revealed an epidural mass in the lower lumbar spine that was heterogeneously enhanced after gadolinium administration. The rim of the mass was low intensity on T2*-weighted images. Local erosions of the adjacent cortical bone were seen with computed tomography in all cases. All patients’ postoperative courses were satisfactory with complete disappearance of radicular symptoms. Conclusions CSEH is a rare disease, and it is difficult to diagnose preoperatively on the basis of diagnostic imaging. The incidence of a low-intensity rim on T2*-weighted images and bone erosions on computed tomography may help differentiate rare CSEH from other lumbar degenerative diseases and epidural space-occupying masses.

Instrumented spinal fixation is ordinarily required in patients who present with myelopathy or cauda equina syndrome secondary to vertebral collapse following osteoporotic thoracolumbar fracture. Posterior spinal fixation is a major surgical option, and partial vertebral osteotomy (PVO) through a posterior approach is occasionally reasonable for achievement of complete neural decompression and improvement of excessive local kyphosis. However, the indications and need for PVO remain unclear. The objectives of this retrospective study were to determine the efficacy and safety of posterior spinal fixation with or without PVO for osteoporotic thoracolumbar vertebral collapse and identify patients who require neural decompression and alignment correction by PVO. We retrospectively reviewed the clinical records of 20 patients (13 females, 7 males; mean age, 67.1 years) who underwent instrumented posterior fixation for osteoporotic thoracolumbar vertebral fracture. Clinical outcomes were assessed by the Japanese Orthopedic Association score and visual analog scale scores in the lumbar and leg areas. PVO was added with posterior spinal fixation in eight patients because neural decompression was incomplete after laminectomy as indicated by intraoperative echo imaging. Neurological and functional recovery significantly improved during follow-up. Clinical outcomes in patients who underwent PVO were similar to those in patients who did not undergo PVO. However, correction of the local kyphotic angle and improvement of spinal canal compromise after surgery was significant in patients who underwent PVO. The patients who required PVO had a less local kyphotic angle in the supine position and higher occupation rate of the fractured fragment in the spinal canal in the preoperative examination.

Nerve sheath myxoma, a myxoid variant of schwannoma, is a dermal tumor that usually occurs in the upper extremities, head and neck region, or trunk; occasionally, however, it has also been reported to develop in the spinal canal. Here, we describe two cases of intraspinal nerve sheath myxoma. Case 1 was a 74-year-old man with left hypochondrial pain. Gadolinium-enhanced magnetic resonance imaging (MRI) of his spine revealed a well-demarcated intradural extramedullary tumor with peripheral enhancement at the Th8 level. Case 2 was a 58-year-old man with lower back and left buttock pain. Gadolinium-enhanced MRI revealed a well-demarcated intradural extramedullary tumor with peripheral enhancement at the Th12-L1 level. Both cases were clinically diagnosed as schwannoma. Histological studies revealed characteristic myxoid lobules which were separated by fibrous septa or bands of more compact cellular area. The tumor cells were diffusely positive for S-100 and focally positive for Schwann/2E, which reacts with Schwann cells and myelin in the peripheral nervous system. The positive reaction to Schwann/2E confirmed the occurrence of peripheral nerve sheath differentiation. Nerve sheath myxoma should be included in differential diagnosis of spinal canal tumors.

Background Multiple osseous loose bodies in the lumbar spine have never been reported. We describe a rare surgical case of multiple osseous loose bodies associated with lumbar isthmic spondylolisthesis. Case Description A 74-year-old man who experienced left foot numbness and bilateral gluteal pain was diagnosed with lumbar spondylolisthesis 7 years previously and managed conservatively. He reported recurrence of the left foot numbness 6 months previously, at which time aggressive (rather than conservative) therapy became a consideration. Radiographs of the lumbar spine revealed L5 isthmic spondylolisthesis with dynamic instability at L5/S1. Magnetic resonance imaging of the lumbar spine revealed multiple mass lesions dorsally located in the lumbar canal. Computed tomography myelography demonstrated multiple osseous materials near the isthmic portion at the L5 level where compression of the dural sac by the lesions induced lumbar canal stenosis. The patient underwent posterior decompression surgery that enabled total removal of the osseous lesions. Intraoperative findings revealed osseous lesions located in the fibrocartilage material and no connection of the lytic portion at the L5 level or ligamentum flavum. Postoperative course of the patient was uneventful as his neurological symptoms improved. Conclusions We described the first instance of multiple loose bodies in the spinal canal with lumbar canal stenosis. It is presumed that long standing minor trauma due to dynamic instability with a trend of hyperossification induced secondary synovial osteochondromatosis forming multiple loose bodies.

Transforaminal lumbar interbody fusion (TLIF) procedure is widely used, but the surgical indications for TLIF in elderly patients remain controversial because of potential risks such as inferior bone quality and higher rate of postoperative complications. Clinical efficacy and operative risk of TLIF in elderly patients are unclear. This study investigated the clinical effect and safety of TLIF for lumbar degenerative spondylolisthesis with radiculopathy or neurogenic claudication in patients aged 70 years or older. The clinical records were retrospectively reviewed of 35 consecutive patients aged 70-86 years (mean 74.8 years) who underwent one or two-level TLIF. The preoperative diagnosis included degenerative spondylolisthesis with segmental instability. Clinical outcomes were assessed by the Japanese Orthopaedic Association score, visual analogue scale, Oswestry Disability Index. Radiological fusion rate was also investigated. Clinical and radiological results were compared with those of 43 younger patients. Clinical outcome measures were significantly improved after operation in the elderly patients, but improvement rates were significantly lower than those of younger patients. Fusion rate was similar in both groups. Overall postoperative complications were increased in aged patients, although the prevalence of complications directly related to surgical technique was not significantly increased. Postoperative complications not related to the surgical procedure were factors affecting poor results. TLIF is acceptable for achieving clinical recovery and lumbar fusion with high radiographic fusion success even in elderly patients, although clinical benefits were limited compared with those of younger patients. Postoperative morbidity was mainly related to general or non-operative site complications.

Background Context Hemorrhage that results from spinal dural arteriovenous fistula (Type I arteriovenous malformation [AVM]) is uncommon. There are some reports of subarachnoid hemorrhage and subdural hematoma caused by Type I spinal AVM, but there are few reported cases of hematomyelia caused by spinal dural arteriovenous fistula. Purpose To describe an interesting patient who had hematomyelia caused by a dural arteriovenous fistula (Type I spinal AVM). Study design A case report. Methods We present a case of a 51-year-old man who presented acute onset epigastric pain, paraplegia, and sensory loss below his nipples. Magnetic resonance imaging and selective spinal angiogram demonstrated hematomyelia, subarachnoid hemorrhage, and spinal arteriovenous fistula fed by the right Th7 intercostal artery. By laminotomy of Th6–8, the varix-like draining vein and intramedurally hematoma were partially removed and the arterial supply was interrupted by coagulation of the right Th7 segmental artery. Results One month after surgery, he regained movement against gravity at the left ankle and toe but no functionally significant improvement. Conclusions It must be kept in mind that spinal dural arteriovenous fistulas (Type I spinal AVM) has possibility of hematomyelia origin, despite the fact that it is extremely rare.

Transforaminal lumbar interbody fusion (TLIF) is widely accepted for the treatment of lumbar arthrodesis. However, the exact characteristics of TLIF depend on the number, location, shape, or materials of the interbody implants, and the type of posterior instrument. Clinical and biomechanical characteristics of each TLIF procedure are still unclear. The present study investigated the clinical and radiological improvements after single level asymmetrical TLIF, in which a single box-shaped spacer was obliquely inserted into the intervertebral space, for lumbar degenerative spondylolisthesis in patients with or without local coronal imbalance (LCI) at the operated level. The clinical records of 60 patients who underwent single level asymmetrical TLIF augmented with the pedicle screw fixation system from January 2005 to January 2011, were retrospectively reviewed. The patients were divided into the LCI group (n = 19) and non-LCI group (n = 41), based on segmental lateral translation or disc wedging at the operated site. Clinical recovery was significantly good in both groups at 2 years after surgery, but improvement of low back pain was significantly worse in the LCI group. Radiological examination revealed that the mean lumbar scoliotic angle was significantly worse in the LCI group postoperatively. Preoperative greater scoliotic angle and coronal off balance of the lumbar spine were related to unfavorable radiological outcomes. The present study showed that single level asymmetrical TLIF is an acceptable method for achieving good clinical and radiological outcomes for patients with symptomatic degenerative spondylolisthesis, however, the clinical benefits and realignment are limited if the patient has LCI at the operated site with greater scoliotic angle or coronal off balance of the lumbar spine.

Patients with spinal degenerative diseases suffer not only neuropathy in the extremities but also lower urinary tract dysfunction(LUTD). Patients with cauda equina syndrome generally need emergency decompression to pelvic visceral function, especially that of the urinary bladder. However, less prominent voiding symptoms can be missed in clinical settings. There is a discrepancy between lower urinary tract symptoms and LUTD. Therefore, urodynamic studies are needed to screen of patients with spinal diseases. Cystometry and urethral sphincter electromyography are useful for increasing our understanding of LUTD but are too invasive for screening. Our protocol for the evaluation of LUTD consists of residual urine measurement and uroflowmetry(UFM). UFM is the simplest and noninvasive urodynamic technique;however, it has the disadvantage of being nonreproducible, which depends on bladder volume, diurnal variation, presence of obstructive disease, and mental stress. UFM was reportedly reproducible in normal individuals in 1979, but was not evaluated in patients with spinal disease. This study examined the reproducibility of UFM in patients with spinal disease. UFM was performed twice in 26 male patients with cervical or lumbar degenerative disease. Maximum urinary flow rate corrected with Siroky's nomogram was reproducible in 23(88.5%)of the 26 patients. A urinary flow curve was reproducible in 25(96.2%)of the 26 patients, and only 1 patient had excessive urination at the 1st UFM and normal urination at the 2nd UFM. The reproducibility of UFM was high in patients with spinal degenerative disease.

The effectiveness of spinal surgery for lumbar canal stenosis was investigated in the elderly. 164 patients with lumbar canal stenosis were surgically treated over 8 years. 125 patients were followed up by letter questionnaire. The outcome and patient satisfaction with the surgical procedures were compared between the 73 younger patients (or = 64 years of age) and the 52 elderly patients (or = 65 years of age). Intermittent claudication was satisfactorily improved in both the younger and the elderly groups. Both simple laminectomy and laminectomy with fusion could equally improve the symptoms of intermittent claudication. Although statistically not significant, there was tendency that laminectomy plus fusion effectively improved the symptoms of back pain and leg pain in both groups. 75% of the younger patients and 67% of the elderly were pleased with the outcome. The present study shows that elderly patients with lumbar canal stenosis should be actively considered for surgical treatment.

A 53-year-old male presented with a rare dorsally sequestrated thoracic disc herniation manifesting as acute low back pain and weakness. He had no history of trauma. Magnetic resonance (MR) imaging demonstrated a mass at T10-11 intervertebral level connected with the T-10 disc. Axial MR imaging showed the mass had surrounded and compressed the dural sac from the lateral and dorsal sites. MR imaging with gadolinium-diethylenetriaminepenta-acetic acid showed slight rim enhancement of the lesion. Computed tomography detected no abnormal calcification. The diagnosis was thoracic disc herniation. Laminectomy resulted in rapid and satisfactory recovery. The histological diagnosis was thoracic disc herniation. MR imaging was very effective for the diagnosis based on the connection between the mass and the disc space. The differential diagnosis includes metastatic epidural tumor, epidural hematoma, and epidural abscess.

The sternal splitting approach for upper thoracic lesions located anterior to the spinal cord is described. The sternal splitting approach can be effectively applied to lesions from the T-1 to T-3 levels. The aortic arch prevents procedures below this level. The approach is straight toward the T1-3 vertebral bodies and provides good surgical orientation. The sternal splitting approach was applied to five patients with metastatic spinal tumors at the C7-T3 levels and three patients with ossification of the posterior longitudinal ligament at the T1-3 levels. No postoperative neurological deterioration occurred. Two patients had postoperative hoarseness. The sternal splitting approach to the upper thoracic spine is recommended for hard lesions, extensive lesions requiring radical resection, and lesions requiring postoperative stabilization with spinal instrumentation.

BACKGROUND Subarachnoid hemorrhage (SAH) with a spinal origin is a rare clinical entity. The most common source of SAH is an arteriovenous malformation. Only six cases of spinal hemangioblastomas causing SAH have been reported. CASE DESCRIPTION This 48-year-old man had experienced severe headache 12 years earlier, which was diagnosed as SAH by computed tomography (CT) scan and lumbar puncture. However, cerebral angiography could not detect either aneurysm or arteriovenous malformation. Thereafter, he spent an uneventful life until he was incidentally diagnosed with a cervical tumor on magnetic resonance imaging (MRI) study for Meniere's disease. The tumor was situated at the cervicomedullary junction, and fed by the left vertebral artery. Histologic findings of the tumor showed features typical of hemangioblastoma. CONCLUSIONS We describe a case of cervical spinal extramedullary hemangioblastoma with a past history of SAH. In our case, the SAH of 12 years ago perhaps occurred from the cervicomedullary junction hemangioblastoma. Since the etiology of SAH could not be detected at the first angiography, not only follow-up reangiography, but also MRI of the spinal cord and spinal angiography could have played an important role.

We describe 5 cases of osteochondroma (OC) originating from lumbosacral spine which caused radiculopathy. Four cases originated from the lumbar spine; all from L4 inferior articular process and presented L5 radiculopathy, the other one case originated from the sacrum; the case from S1 superior articular process presented L5 radiculopathy. In all cases, definitive diagnosis was made with histopathological findings; typical cartilaginous capping was confirmed. The functional recovery was completed in all 5 cases. As for imaging study, post myelography computed tomography revealed the most diagnostic tool for understanding the relationship between nerve tissue and the tumor. In all 5 patients, the tumors contained a high signal intensity on T2-weighted images in the central medullary area. OCs are sometimes difficult to diagnose because they mimic other conditions like bony spur formation due to osteoarthritis, so we should never fail to confirm the histopathological diagnosis of such lesions when suspected.

In the clinical diagnosis of lumbosacral radicular symptoms, dermatome maps are commonly used, by which the segmental location of the affected nerve can be determined. However, the diagnosis is often difficult because the pattern of sensory disturbance does not necessarily match the patterns of classical dermatomes, and there are many dermatome maps made by different methods. The author examined the area of pain and numbness in cases of lumbosacral radiculopathy. Clinical features of pain and numbness in consecutive seventy three cases of lumbosacral radiculopathy were investigated (L3: n=13, L4-S1: n=20). Patients of L3 radiculopathy showed symptoms at the upper buttock and ventral surface of the thighs, knees and upper ventral surface of the legs. Patients of L4 radiculopathy showed symptoms at the ventro-lateral surfaces of the thigh and leg. The distinctive region, defined as the region having 100% superimposition, of L4 radiculopathy was the lateral part of the shin. Patients of L5 radiculopathy showed symptoms at the lateral surfaces of the thigh and leg. The distinctive region was the upper buttock. Patients of S1 radiculopathy showed symptoms at the lower buttock, dorso-lateral part of the leg and lateral part of the foot. The distinctive region was the lateral part of the calf. It was found that the regions of pain and numbness formed a continuous band-like zone from thigh to leg in 8% of L3, 45% of L4 and L5, and 35% of S1 radiculopathy. Using a visual analogue scale, the degree of leg pain was more severe than low back pain in 68% of the patients, but in 5% of patients, low back pain was more severe.

A 21-year-old woman presented with cervical myelopathy due to nontraumatic cervical disc herniation associated with cervical canal stenosis. The patient underwent removal of the herniated disc and anterior fusion with an autogenous iliac crest bone graft. After surgery, the patient showed satisfactory improvement. Cases of cervical disc herniation in our center and reported cases without cervical trauma in either young adults or in childhood were reviewed retrospectively. We discuss the pathogenesis of cervical disc herniation in our young patient in the context of these other cases. Cervical disc herniation rarely occurs before the age of 30 years. A history of cervical trauma and preexisting fusion of the cervical spine are risk factors for cervical disc herniation. The present case is the youngest known of nontraumatic disc herniation without other underlying disease. Hypermobility due to neck cracking and a relatively narrow spinal canal might have been important in causing cervical myelopathy by disc herniation.

The significance and role of cervical soft disc hernia in ossification of the posterior longitudinal ligament were investigated based on 54 surgical cases. The types of ossification of the posterior longitudinal ligament were divided into three sub-types: segmental, continuous, and mixed types. In the current series, there were 29 segmental type, 12 continuous type, and 13 mixed type. In the 29 segmental type, 23 patients had accompanying cervical disc hernias (79%). In the 12 continuous type, only 2 patients (17%), and in the 13 mixed type, 5 patients (33%), had accompanying disc hernias. According to the current study, an essential difference exists between the segmental type and the continuous or mixed types. In addition, the current result seems to indicate that, at least in the segmental type, disc herniation is not the promoting or initiating factor of ossification of the posterior longitudinal ligament, but that, in these cases, the fragility of the posterior longitudinal ligament may increase the chance of a disc hernia.

Pseudolocalizing signs in lumbar spinal disease seems to be rarely encountered. To our knowledge, only six cases which caused L5 monoradiculopathy due to upper lumbar lesions have been described. We retrospectively reviewed patients with similar signs in our center, and we discussed the pathogenesis of such interesting neurological signs depending on our own and reported cases.Between January, 2005 and August, 2010, 1,229 patients with lumbar degenerative disease underwent spinal decompression surgery, 3 of which (0.24%) presented with L5 monoradiculopathy due to upper compressive lesions in lumbar spinal disease.As pathological mechanisms, 2 hypotheses are speculated: Direct compression at the epiconus level or circulatory disturbance at the nerve root itself. If the level of the conus medullaris is situated at the lower lumbar level, such as L2 level, a compressive lesion at the L1-2 level, for example lumbar disc herniation, can compress the L5 nerve root resulting in L5 nerve palsy. However, the affected level below the cauda equina doesn't seem to compress only the L5 nerve root directly, because the cauda equina is mobile enough to avoid the compression. Another speculated mechanism is the so-called circulatory disturbance. When the cauda equina is remarkably compressed at the upper level, less severe compressive change may cause selective monoradiculopathy at the lower lumbar level. Based upon the presented analyses, we adopt the circulatory mechanism in our cases as the causative factor in lumbar pseudolocalizing signs.

An 84-year-old man presented with a rare case of spinal epidural granuloma with intratumoral hematoma resulting in acute paraplegia. He was admitted to our hospital because of lumbago and hematemesis following a fall 10 days before. Progressive paraparesis occurred 2 days after admission. Neurological examination showed paraplegia and hypesthesia below the T10 level. Thoracic radiography revealed some spondylotic changes of the thoracic vertebrae without osteolytic changes. Sagittal T(1)- and T(2)-weighted magnetic resonance imaging of the thoracic spine demonstrated a hyperintense epidural mass lesion compressing the dorsal portion of the thoracic spinal cord at T10-11 space. Emergency laminectomy was performed, and the epidural encapsulated hematoma and elastic yellowish mass adhered to the dura mater were totally removed. Histological examination of the excised specimens showed a granuloma. Motor weakness improved after surgery, and he could walk with a cane about 3 months after surgery. The minor spinal injury probably caused intratumoral hemorrhage within a previous epidural granuloma, suddenly resulting in the paraplegic symptoms.

A 52-year-old male was admitted because of right hemiparesis. Computed tomography scan showed a low-density area in the basal ganglia on the left side. Left carotid angiography showed an aneurysm of the extracranial internal carotid artery at the level of the C1-C2 vertebral body. Right carotid angiography also showed an aneurysm of the extracranial internal carotid artery. Because there were neither steno-occlusive changes in the intracranial vessels nor abnormality in the heart, the right hemiparesis seemed to be due to embolism from the extracranial aneurysm. Aneurysmectomy and end-to-end anastomosis of the left internal carotid artery were performed. Extracranial carotid aneurysms are rare conditions. In surgery on these aneurysms, ischemic changes of the brain during arterial clump must be detected and treated. Hypothermia, induced hypertension, and/or internal shunting have been used during arterial clump. The pathogenesis, symptoms, prognosis, and surgical treatments of these aneurysms are discussed.

A 26-year-old male with an intracranial teratoma, metastasizing from a testicular yolk sac tumor refractory to cis-diamminedichloroplatinum (CDDP), vinblastin, and bleomycin (PVB) therapy, was successfully treated with a combination of etoposide (VP-16), CDDP, and ACNU (salvage chemotherapy). Emergency surgery for subcortical hemorrhage discovered the metastasis, diagnosed as a yolk sac tumor. CDDP chemotherapy failed to prevent recurrence, and total removal was impossible due to subdural invasion. He underwent radiation therapy and salvage chemotherapy. A third operation found only scar tissue. Maintenance salvage chemotherapy was continued. He was doing well 30 months after the first operation.

A 57-year-old man presented with an extremely rare osteoma originating from the left L-5 inferior articular process and causing lumbo-crural sciatica. Postmyelography computed tomography and magnetic resonance imaging showed an osteoma compressing the spinal nerve root at the lateral recess. Decompression facetectomy and excision of the lesion followed by transforaminal lumbar interbody fusion between L-5 and S-1 provided complete relief from the symptoms. Histological examination confirmed the diagnosis of benign osteoma. The previous seven cases of spinal osteoma involved the vertebral body, pedicle and posterior elements. Spinal osteomas should be considered in the differential diagnosis of benign lesion originating from the articular process.

A 44-year-old male presented with a solitary cerebellopontine angle (CPA) metastasis from lung cancer. His initial symptoms were vertigo and hearing loss beginning 5 months after the diagnosis of the primary cancer. Two months later, right facial paresis developed. His neurological deterioration was rapid. Magnetic resonance (MR) imaging with enhancement disclosed the CPA tumor. The tumor was partially removed through the retroauricular retromastoid approach. Histological examination of the specimen revealed adenocarcinoma. The characteristic rapidly progressive symptoms and MR imaging with enhancement are the most sensitive and essential examinations for this lesion.

Object. A variety of factors may affect surgery-related outcome in patients with ossification of the ligamentum flavum (OLF) of the thoracic spine. The aim of this study was to determine these factors on the basis of preoperative clinical and radiological findings. Methods. The authors treated 31 cases of symptomatic thoracic OLF between 1988 and 1999. The following factors were retrospectively studied: patient age, sex, morbidity level, initial symptoms, chief complaint, duration of symptoms, patellar reflex, Achilles reflex, computerized tomography (CT) finding, presence of intramedullary change determined by magnetic resonance imaging, coexistent spinal lesions, preoperative grade, and postoperative grade. A decompressive laminectomy was performed in all cases. In 29 patients (94%) improved symptoms were demonstrated postoperatively. In terms of functional prognosis, the preoperative duration of symptoms was significantly shorter in the group of patients with excellent outcomes than in those with fair outcomes (p < 0.05). No significant difference was observed in the correlation between other factors. To evaluate the degree of preoperative thoracic stenosis and the severity/extent of OLF-induced spinal compression, we used an original OLF CT scoring system. A score of excellent on the CT scale tended to indicate an excellent prognosis (p < 0.01). Conclusions. Thoracic OLF frequently develops in the lower-thoracic spine in middle-aged men, and it is complicated by various spinal lesions in many cases. Early diagnosis and treatment are important for understanding the clinical symptoms and imaging diagnosis because the present findings suggest that a delay in diagnosis and treatment correlates with the functional prognosis postoperatively.

Damage to the paraspinal muscle after various lumbar back surgery procedures was evaluated by measuring the paraspinal muscle thickness preoperatively and postoperatively in 89 patients, 61 males and 28 females. There were 42 single interlaminar level procedures (SL group), 13 multiple interlaminar level procedures (ML group), and 34 posterolateral fusion procedures (PLF group). Changes in paraspinal muscle thickness were evaluated at more than 10 months after surgery, because muscle swelling continued as long as 10 months after surgery, and then reduced as the edema subsided. Postoperative serum creatine phosphokinase (CPK) level on postoperative day 2 was also measured. The decrease of paraspinal muscle thickness was significantly larger in the PLF group than in the SL group (-12.9% and -2.7%, respectively, p < 0.02). There was no significant correlation between postoperative serum CPK level and decrease of paraspinal muscle thickness. However, the postoperative elevation of serum CPK level was significantly higher in the PLF group than in the SL and ML groups (979 +/- 114 vs. 292 +/- 45 and 410 +/- 44 IU/l, respectively, p < 0.001). In conclusion, posterolateral fusion is the most invasive procedure of the paraspinal muscles in various lumbar back surgery procedures. Paraspinal muscle damage during lumbar back surgery may be one of the most important factors that causes atrophy of the muscles.

Study Design. A case report. Objectives. To understand a rare case of ligamentum flavum progressive hematoma. Summary of Background Data. Previously there were only two reports about ligamentum flavum hematoma. Methods. A patient was surgically treated for ligamentum flavum hematoma causing progressive L5 radiculopathy. Clinical and neuroradiologic features were reported, and the literature was reviewed. Results. The etiology of this case could not be defined except by minor back injury. In spite of conservative therapy, the symptoms were progressive for 7 months. Magnetic resonance imaging demonstrated the epidural mass lesion at L4–L5 that was continuous with the ligamentum flavum. The mass was hypointense in T1-weighted images and central hyperintense and marginal hypointense in T2-weighted images. The margin was well enhanced by Gd-DTPA administration. After removal of the mass lesion, the patient’s symptoms completely resolved. Before surgery, accurate diagnosis was difficult even based on magnetic resonance imaging and was achieved after histologic examinations. Conclusions. Surgery could be a choice of the treatment modality to resolve symptoms in ligamentum flavum hematoma.

A 74-year-old male presented with right hemiparesis greater in the lower than the upper extremity. He had no apparent head trauma. He had been treated with anticoagulants for cerebral and myocardiac infarction. Computed tomography (CT) and magnetic resonance imaging demonstrated an unusual combination of subdural hematomas in the interhemispheric space on the left, and the left temporoparietal and right frontotemporooccipital regions. The left convexity hematoma was irrigated through a single burr hole. Postoperatively, the size of the left convexity hematoma was diminished and the left interhemispheric subdural hematoma disappeared. However, his consciousness deteriorated, and a second irrigation of the recurrent left convexity hematoma was performed 7 days after the first surgery. CT obtained 3 days after the second operation showed a right interhemispheric subdural hematoma, which diminished spontaneously. The convexity hematoma on the left reaccumulated, and was treated by shunting. His neurological status did not improve, and he died from myocardial infarction 39 days later. Irrigation of convexity hematoma may be effective to treat an associated ipsilateral interhemispheric subdural hematoma.

✓ The authors report a rare case of intraspinal thoracic mobile neurinoma in a 51-year-old man. The clinical symptoms, especially thoracoabdominal discomfort, changed remarkably according to the patient's posture. Magnetic resonance images demonstrated that the level of the caudal end of the tumor varied between T4–5 and T9–10 with changes in the patient's position. Intraoperative myelography was useful in identifying the tumor location and choosing the level of the laminectomy.

Thoracic lesions present several clinical problems, particularly in their diagnosis and treatment, compared with cervical or lumbar lesions. Since 1983, 18 cases of thoracic space lesions, excluding spinal tumors or trauma have been experienced: nine cases of ossification of yellow ligament (OYL), five of ossification of posterior longitudinal ligament (OPLL), and four of disc hernia (DH). In these 18 patients, problems of clinical manifestations, neuroradiological examination, and surgical approaches are analyzed and discussed. As clinical manifestations, there was a preponderant occurrence in males in the OYL group, while in the OPLL group all the patients were females. OYL and DH occurred at lower thoracic levels. Thirteen of the 18 patients showed combined lesions either in the cervical or in the lumbar regions, such as cervical OPLL, cervical spondylosis, lumbar DH, and lumbar canal stenosis. In the neuroradiological examinations diagnosis of the upper thoracic lesions was difficult. Computed tomography (CT) scan with intrathecal metrizamide injection seemed essential for examination of ossified thoracic lesions. However, because CT imaging of the entire spine is impractical, efficient use of this examination requires previous localization of the offending vertebral level from either the neurological findings or other neuroradiological examinations such as myelography. Magnetic resonance imaging seemed most useful for ruling out the thoracic compressing lesions. As for surgical approaches, posterior decompression was effective for OYL and the anterior approach was useful for OPLL and DH. In patients with “tandem lesions, ” neurological and neuroradiological findings played an important role in deciding the responsible site.

A 43-year-old, right-handed man was admitted complaining of peculiar movements of his left hand. Computed tomography scan and magnetic resonance imaging showed an infarct area in the territory of the left anterior cerebral artery. The abnormal movements of the left hand were diagnosed as so-called alien hand sign. This patient also exhibited mirror writing with his left hand. The clinical manifestations and neuroradiological findings of this case are described in detail, and the possible mechanisms of these extremely rare combinations of alien hand sign and mirror writing are discussed.

Cervical spondylotic myelopathy usually arises in patients in their late 40s or early 50s, most frequently at the C5/6 and C6/7 levels. Recently, excellent results have been attained with microsurgery in cases of cervical spondylosis. On the other hand, treatment of cervical spondylotic myelopathy in patients with athetoid dystonic cerebral palsy entails several problems. The authors report three cases of such troublesome myelopathy. A 34-year-old male with severe athetoid movement showed cervical spondylotic myelopathy. Myelography and magnetic resonance (MR) imaging demonstrated compression of the spinal cord through the C3-C5 levels. A 47-year-old female with athetoid dystonic cerebral palsy presented myelopathy. Myelography and MR imaging showed instability and spinal cord compression at the C5/6 level. A 34-year-old male with spasmodic torticollis showed C6 radiculopathy due to cervical disc hernia at the C5/6 level. Cervical anterior decompression with interbody fusion brought temporary improvement in all the three patients. However, such problems as slippage of Halo-vest, difficulty in eating during Halo-vest fixation, relapse of neurological deficit, were experienced. Due to postoperative cervical instability, cervical laminectomy is considered to be contraindicated in such patients. Anterior decompression with bone fusion has been reported effective, but, if athetoid dystonia continues, there is a potential for myelopathic deterioration due to spondylotic changes adjacent to the fused vertebrae.

Changes in acid phosphatase activity in the cerebrovascular system and brain parenchyma in SHR were investigated histochemically. An increased activity of the enzyme was demonstrated in the SHR endothelial and medial smooth muscle cells of the cerebral arterial system as compared to the control. The pericytes of intraparenchymal blood vessels also showed an intensified enzyme activity. The enzyme activity increased with advancing age. In SHR brain parenchyma, the enzyme activity was decreased in the cortical nerve cells. Glial cells with the enzyme activity were increased in number and showed an intensified activity. Causative factors of changes in acid phosphatase activity in SHR cerebral arteries and parenchyma were discussed.

Thirty-five cases of cervical soft disc were analyzed in terms of symptomatic, myelographic, and computed tomographic (CT) features. The patients, 24 males and 11 females, ranged in age from 33 to 69 years (mean, 48 years). The clinical manifestations were classified into six patterns according to the subjective and objective findings. On myelography, lateral views provided useful information in patients with myelopathy, whereas posteroanterior views were more informative in patients with radiculopathy. On the basis of metrizamide CT findings, the herniated discs could be classified as medial, mediolateral, or lateral. According to the operative findings, disc herniation could be characterized as either protruded, with an intact posterior longitudinal ligament, or prolapsed, with laceration of the ligament. A medial orientation was well correlated with protrusion and lateral and mediolateral herniation with prolapse. Although the mechanisms of myelopathy due to cervical soft disc are obscure, both direct compression by the herniated disc material and secondary circulatory disturbance within the spinal cord appear to play important pathogenetic roles.

A 50-year-old male with advanced gastric cancer underwent artificial anal colostomy to improve ileus under lumbar anesthesia. After surgery the patient developed paraplegia. Myelography and computed tomography revealed an intradural hematoma at the thoracolumbar region. Emergency laminectomy showed that the subarachnoid hematoma was compressing the spinal cord at the levels from Th10 to L2. Lumbar puncture, myelography, and lumbar anesthesia are performed very often because of their clinical importance and benefits, and complications of these procedures are infrequent and usually insignificant. However, on rare occasions serious complications do occur, among which intraspinal canal hematoma causing paraplegia is the most severe. According to the literature, epidural hematomas occur most often, followed by subdural hematomas, whereas subarachnoid hematoma after lumbar puncture is extremely rare. Among the proposed factors that lead to this complication are bleeding tendency, thrombocytopenia, anticoagulant drug therapy, multiple punctures, and pre-existing narrow spinal canal.

Serious complications of microvascular decompression operations for trigeminal neuralgia or hemifacial spasm are reported. Among 278 patients who underwent microvascular decompression, 9 serious complications were observed: 1 intracerebellar hematoma with acute hydrocephalus, 1 cerebellar swelling with acute hydrocephalus, 1 supratentorial acute subdural hematoma, 2 status epilepticus, 1 infarction of the brain stem, 1 subarachnoid hemorrhage due to traumatic aneurysm, and 1 infarction in the territory of the posterior cerebral artery. Of the 9 patients with such complications, 2 died. The possible causes of such serious complications are discussed. (Neurosurgery 22:348-352, 1988)

The functional abnormalities of the cells in the cardiovascular system in SHR were revealed by enzyme histo-cytochemical study. The enzymatic activity was usually increased in the area where the arteries branched and in proliferating cells in the thickened wall. Such was more remarkable in the distorted arteries with aging. Functional roles of these 4 enzymes were discussed.

Hanakita J., Hazama F., Amano S., Yamada E. & Handa H. (1980) Neuropathology and Applied Neurobiology 6, 471–482 Histochemical study on oxidative enzyme activity in the brain, particularly of astrocytes, in spontaneously hypertensive rats In order to obtain indirect information concerning brain oedema or increased vascular permeability under hypertensive conditions, the enzyme responses of astrocytes in the brains of spontaneously hypertensive rats were histo-chemically investigated. Reactions for oxidative enzymes, such as NADH2-, NADPH2-tetrazolium reductases and succinate dehydrogenase were performed on SHR brains of various ages. In the hypertensive rats, proliferation, hypertrophy and increased enzyme activity were observed in astrocytes, particularly in the white matter. This activation of astrocytes appeared at 12 13 weeks-of-age and increased with advancing age. These findings suggest that increased vascular permeability of the materials in the smaller molecules begins in the early stage of the development of hypertension before the breakdown of the blood-brain barrier. Many degenerating astrocytes, showing clasmatodendritic changes, were observed in severely oedematous regions or around cystic foci in the white matter. The changes in astrocytic function seem to be related to the development of the parenchymal changes, particularly of the white matter in the chronic hypertensive state.

Acid phosphatase activity in the cerebral arterial system in spontaneously hypertensive rats (SHR) was cytochemically investigated. In the endothelial and medial smooth muscle cells, endoplasmic reticulums and Golgi complex revealed an intense acid phosphatase activity and primary lysosomes containing the high enzyme activity were found to be augmented in number. The enzyme activity was demonstrated in the vacuolated secondary lysosomes and in the intercellular spaces of the arterial walls. Lytic changes of the arterial mural cells and vessel matrix due to lysosomal enzymes were also evident. Causes of the lysosomal enzyme induction and roles of the enzyme in the developmental mechanism of hypertensive cerebrovascular changes in the SHR brain are discussed.

A case of spinal cord compression due to postoperative cervical pseudomeningocele is reported. A 63-year-old man had undergone osteoplastic laminectomy of the C-3 through C-6 laminae for quadriplegia after a traffic accident 1 year and 4 months earlier. Computer-assisted tomography with metrizamide injection showed a pseudomeningocele in the paraspinous area at the C-3 through C-6 level.