Shinnosuke Nakahara

A pathologic study of discs in the elderly: Separation between the cartilaginous endplate and the vertebral body

Eighty-eight autopsy specimens from L4-5 lumbar discs of cadavers with an average age of 77.6 years were examined radiologically and histopathologically. They were classified into three groups by the height of intervertebral disc space: slightly degenerated (57 cases), moderately degenerated (25 cases), and severely degenerated (6 cases). Cartilaginous end-plate rupture was found most commonly in the severely degenerated group. Reverse orientation of the anulus fibrosus was found in one third of all specimens. End-plate was separated from vertebral body in 45 cases (51.1%) of 88 specimens. From the findings it is suggested that the end-plate is avulsed from the vertebral body under the precondition of separation and then herniated with anchoring anulus fibrosus. This type of herniation occurs more often than herniation of the nucleus pulposus in the elderly.

Pathogenesis and diagnosis of delayed vertebral collapse resulting from osteoporotic spinal fracture

BACKGROUND CONTEXT In recent years there have been an increasing number of reports on surgical cases involving delayed neurological deficits caused by vertebral collapse after osteoporotic vertebral fracture. PURPOSE We do not yet know which patients are most susceptible to delayed vertebral collapse and subsequent neurological deficits, or whether this pathological condition can be prevented or predicted. In this study, we investigated the mechanism of progression and radiographic features characteristic of this disease, and we report here the predictive or risk factors for delayed osteoporotic vertebral collapse. STUDY DESIGN Retrospectively, we investigated the pathogenesis and diagnosis of delayed vertebral collapse with neurological deficit resulting from osteoporosis. PATIENT SAMPLE A total of 28 patients (7 men and 21 women) with neurological deficits resulting from vertebral collapse caused by osteoporotic vertebral fractures were the subjects for this study. OUTCOME MEASURES Comparisons and investigations about clinical features and radiographic findings between the patient group of delayed vertebral collapse with neurological deficits and the group of osteoporotic spinal fracture with no neurological deficits. METHODS The following factors were examined: the cause of injury; the length of time from injury, or the onset of pain, to the onset of neurological symptoms; radiographic findings obtained during the above period; the clinical course of vertebral fracture on plain X-ray films; time of appearance of the intravertebral cleft, and its localization and changes. RESULTS Six patients were hospitalized and prescribed a period of 2 weeks of bed rest followed by the fitting of a corset; seven outpatients were corseted but not prescribed bed rest; 15 patients were given medication only at an outpatient clinic. At radiography, intravertebral clefts were detected in 22 patients (79%) during the period from the appearance of pain to the onset of neurological deficit. In 14 patients (50%) who were radiographed every 1 to 2 weeks from the injury to the onset of neurological symptoms, the course of progression to collapse of the vertebral body could be observed. CONCLUSION Initial correct diagnosis and immobilization are important in preventing the delayed collapse with neurological deficit. The presence of an intravertebral cleft and instability of the affected vertebra represent risk factors for vertebral collapse with neurological deficit, requiring careful observation.

Surgical treatment of cervical spondylotic myelopathy complicating athetoid cerebral palsy

Operative treatment was performed in nine patients with cervical spondylotic myelopathy complicating athetoid cerebral palsy. The first two patients were treated by laminectomy, and the other seven by anterior interbody fusion. The symptoms in both the laminectomy patients improved after operation, but became worse again when cervical instability developed; they then had to have an anterior fusion in addition. In six of the seven patients who had primary anterior fusion a halo-cast (or a halo-vest) was used to keep the cervical spine immobile, and good bony fusion was obtained with satisfactory results. However, in one patient no halo apparatus was used, bony union did not occur and the radiculopathy reappeared. In cervical myelopathy complicating athetoid cerebral palsy laminectomy is contra-indicated; anterior fusion combined with a halo apparatus is, however, satisfactory.

SAPHO syndrome associated spondylitis.

The concept of synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome has been well clarified, after Chamot et al. suggested this peculiar disorder in 1987. The most commonly affected site in SAPHO syndrome is the anterior chest, followed by the spine. However, the clinical course and taxonomic concept of SAPHO spinal lesions are poorly understood. This study was performed to analyze: (1) the detailed clinical course of spinal lesions in SAPHO syndrome, and (2) the relationship between SAPHO syndrome with spinal lesions and seronegative spondyloarthropathy. Thirteen patients with spondylitis in SAPHO syndrome were analyzed. The features of spinal lesions were a chronic onset with a slight inflammatory reaction, and slowly progressing non-marginal syndesmophytes at multi spinal levels, besides the coexistence of specific skin lesions. SAPHO syndrome, especially spinal lesions related to palmoplantar pustulosis, can be recognized as a subtype of seronegative spondyloarthropathy.

Aortic pseudoaneurysm in the L3–L4 disc space after lumbar disc surgery: A CASE REPORT

We report a patient who developed an aortic pseudoaneurysm in the L3-L4 disc space after lumbar disc surgery. The diagnosis was made by MRI and aortography, and repair using a prosthetic graft and anterior fusion was successful. We discuss the predisposing factors, the clinical picture and management of vascular injuries during disc excision.

Diagnostic validity of space available for the spinal cord at C1 level for cervical myelopathy in patients with rheumatoid arthritis.

Study Design. Retrospective cohort study. Objective. To evaluate diagnostic validity of space available for the spinal cord (SAC) at C1 level for myelopathy in patients with rheumatoid arthritis (RA). Summary of Background Data. The relationship of SAC at C1 level with myelopathy has been evaluated by relatively small number of the patients, and 2 criteria have been proposed. Methods. Two cohorts of the patients with RA were established. Group A consisted of 140 patients with myeopathy due to upper cervical involvement selected from the database. Group B consisted of 99 patients with upper cervical subluxation, but not associated with myelopathy selected from the consecutive series of the hospitalized patients. Distributions of SAC at C1 level in both groups were evaluated. Efficacy indexes for screening (sensitivity, specificity, etc.) were calculated for these patients’ population by previously demonstrated 2 criteria. In addition, analysis according to receiver operating characteristic (ROC) curve was performed. Results. The average values of SAC were 11.1 mm in Group A and 16.5 mm in Group B. When cut-off point for myelopathy was defined as 13 mm or less, sensitivity and specificity were 82% and 85%, respectively. When it was defined as 14 mm or less, sensitivity increased (88%) while specificity decreased (74%). Accuracies by these 2 criteria were almost the same (83%, 82%). The left upper corner point of ROC curve was located between these 2 cut-off points. Conclusion. Distributions of SAC showed that SAC was a reliable parameter for relating myelopathy in patients with upper cervical subluxation in RA. The plots according to ROC curve showed adequacy of previously demonstrated 2 cut-off points. For the purpose to screen the patients with high risk for myelopathy, 14 mm or less was recommended as a cut-off point of SAC.

First thoracic disc herniation with myelopathy

SummaryThe case of a patient with progressive paraparesis due to first thoracic disc herniation is reported. He was treated successfully with anterior interbody fusion by the Smith-Robinson approach. An anterior approach is desirable for surgical treatment of T1/2 disc herniation, and up to this level the Smith-Robinson approach, without thoracotomy, is entirely possible.

Mobility of the cervical spine after anterior interbody fusion for spondylotic myelopathy—a radiographic study

To study the influence of anterior body fusion on the adjacent vertebral discs, the radiographs of 101 patients with cervical spondylotic myelopathy (CSM) were analysed, and cervical mobility and intersegmental mobility were determined. Single level fusions were carried out in 29 patients, double level fusions in 45 patients and triple level fusions in 27 patients. Cervical mobility after surgery was inversely proportional to the number of fused discs. Angles were reduced by fusion in proportion to the number of fused discs. The compensatory increase in motion at the disc adjacent to the fusion was slight, and the number of fused discs had little influence on the compensatory increase in motion. Regarding cervical motion, extension and flexion were limited to the same extent in single level fusions, flexion was more limited in double level fusions and limitation of extension was much larger in triple level fusions. Seven patients underwent a second operation after a double level fusion, and one patient underwent a second operation after a single level fusion. In all five patients whose radiographs before the second operation were available, flexion was adequately limited, but extension was not limited at all. These results suggest that the failure to limit extension is responsible for the recurrence of CSM.

Visualization of cerebrospinal fluid flow in syringomyelia through noninvasive magnetic resonance imaging with a time-spatial labeling inversion pulse (Time-SLIP)

Context: We report a case of syringomyelia assessed by magnetic resonance imaging (MRI) with a time-spatial labeling inversion pulse (Time-SLIP), which is a non-contrast MRI technique that uses the cerebrospinal fluid (CSF) as an intrinsic tracer, thus removing the need to administer a contrast agent. Time-SLIP permits investigation of flow movement for over 3 seconds without any limitations associated with the cardiac phase, and it is a clinically accessible method for flow analysis. Findings: We investigated an 85-year-old male experiencing progressive gait disturbance, with leg numbness and muscle weakness. Conventional MRI revealed syringomyelia from C7 to T12, with multiple webs of cavities. We then applied the Time-SLIP approach to characterize CSF flow in the syringomyelic cavities. Time-SLIP detected several unique CSF flow patterns that could not be observed by conventional imaging. The basic CSF flow pattern in the subarachnoid space was pulsatile and was harmonious with the heartbeat. Several unique flow patterns, such as bubbles, jumping, and fast flow, were observed within syringomyelic cavities by Time-SLIP imaging. These patterns likely reflect the complex flow paths through the septum and/or webs of cavities. Conclusion/Clinical Relevance: Time-SLIP permits observation of CSF motion over a long period of time and detects patterns of flow velocity and direction. Thus, this novel approach to CSF flow analysis can be used to gain a more extensive understanding of spinal disease pathology and to optimize surgical access in the treatment of spinal lesions. Additionally, Time-SLIP has broad applicability in the field of spinal research.