Atsuomi Aiba

C5 palsy following anterior decompression and spinal fusion for cervical degenerative diseases

Postoperative C5 palsy is a common complication after cervical spine decompression surgery. However, the incidence, prognosis, and etiology of C5 palsy after anterior decompression with spinal fusion (ASF) have not yet been fully established. In the present study, we analyzed the clinical and radiological characteristics of patients who developed C5 palsy after ASF for cervical degenerative diseases. The cases of 199 consecutive patients who underwent ASF were analyzed to clarify the incidence of postoperative C5 palsy. We also evaluated the onset and prognosis of C5 palsy. The presence of high signal changes (HSCs) in the spinal cord was analyzed using T2-weighted magnetic resonance images. C5 palsy occurred in 17 patients (8.5%), and in 15 of them, the palsy developed after ASF of 3 or more levels. Among ten patients who had a manual muscle test (MMT) grade ≤2 at the onset, five patients showed incomplete or no recovery. Sixteen of the 17 C5 palsy patients presented neck and shoulder pain prior to the onset of muscle weakness. In the ten patients with a MMT grade ≤2 at the onset, nine patients showed HSCs at the C3–C4 and C4–C5 levels. The present findings demonstrate that, in most patients with severe C5 palsy after ASF, pre-existing asymptomatic damage of the anterior horn cells at C3–C4 and C4–C5 levels may participate in the development of motor weakness in combination with the nerve root lesions that occur subsequent to ASF. Thus, when patients with spinal cord lesions at C3–C4 and C4–C5 levels undergo multilevel ASF, we should be alert to the possible occurrence of postoperative C5 palsy.

The Extent of Ossification of Posterior Longitudinal Ligament of the Spine Associated with Nucleotide Pyrophosphatase Gene and Leptin Receptor Gene Polymorphisms

Study Design. A case-control study using radiograph findings and the PCR assay with regard to the susceptibility and the severity of ossification of posterior longitudinal ligament of the spine (OPLL). Objective. To analyze whether polymorphisms of the nucleotide pyrophosphatase (NPPS) gene and the leptin receptor gene predispose to an increased frequency and severity of OPLL. Summary of Background Data. The NPPS gene is responsible for ectopic ossification in the ttw mouse, an animal model for OPLL. The Zucker fatty rat, another animal model for OPLL, has a missense mutation in the leptin receptor gene. Methods. Analysis of 172 OPLL patients and 93 non-OPLL controls was performed. Radiographs of the cervical, thoracic and lumber spine were analyzed to determine whether OPLL was present and to what degree. Genomic DNA was extracted from all participants. Polymorphisms of the NPPS gene and the leptin receptor gene were analyzed using the PCR assay. The association of the polymorphisms with the development and extent of OPLL were statistically evaluated. Results. No significant association was found between the polymorphisms and the existence of OPLL in both the NPPS and the leptin receptor genes. However, the IVS20–11delT variant in the NPPS gene and the A861G variant in the leptin receptor gene were more frequent in patients with OPLL in the thoracic spine compared with patients whose OPLL was restricted to the cervical spine. Conclusion. The present results suggest that the IVS20–11delT variant of the NPPS gene and the A861G variant of the leptin receptor gene are associated with more extensive OPLL, but not with the frequency with which it occurs.

Cervical myelopathy in patients with ossification of the posterior longitudinal ligament

OBJECT The authors assessed the clinical course in patients with a narrowed cervical spinal canal caused by ossification of the posterior longitudinal ligament (OPLL), but who have no or only mild myelopathy. Additionally, the authors analyzed the factors contributing to the development and aggravation of myelopathy in patients with OPLLinduced spinal canal stenosis. METHODS Between 1997 and 2004, the authors selected treatments for patients with cervical OPLL in whom the residual space available for the spinal cord was < or = 12 mm. Treatment decisions were based on the severity of myelopathy at presentation. Twenty-one patients with no or mild myelopathy (defined as a Japanese Orthopaedic Association [JOA] scale score > or = 14 points) received conservative treatment, with a mean follow-up period of 4.5 years. In 20 patients with moderate or severe myelopathy (JOA scale score < 14 points), the authors performed surgery via an anterior approach. The clinical course in these patients was assessed with the JOA scale and the OPLL types were classified. The authors evaluated the range of motion between C-1 and C-7, the developmental segmental sagittal diameter, the percentage of spinal canal diameter occupied by the OPLL (% ratio), and the residual space available for the spinal cord on cervical radiographs; T2-weighted MR images were examined for high signal changes (HSCs). RESULTS In the conservative treatment group, 8 patients showed improvement, 12 remained unchanged, and 1 patients condition became slightly worse during the observation period. Fifteen patients in this group had mixedtype, 3 had continuous-type, 2 had localized-type, and 1 had a segmental-type OPLL. In the surgically treated group, there were 12 patients with segmental-type, 10 patients with mixed-type, and 1 with localized-type OPLL. The mean range of motion at C1-7 was 36.4 degrees in the conservatively treated group and 46.5 degrees in the surgical group (p < 0.05). No significant difference was seen between the groups in terms of developmental segmental sagittal diameter, % ratio, or residual space available for the cord. No HSCs were noted in the conservative group, while 17 patients in the surgical group had HSCs (p < 0.05). CONCLUSIONS In the present study, the authors demonstrate that the mobility of the cervical spine and the type of OPLL are important factors contributing to the development and aggravation of myelopathy in patients with OPLLinduced spinal canal stenosis. The authors advocate conservative treatment in most patients with OPLLs who have no or only mild myelopathy, even in the presence of spinal canal narrowing.

Abnormal course of the vertebral artery at the craniovertebral junction in patients with Down syndrome visualized by three-dimensional CT angiography

IntroductionWe determined the incidence of vertebral artery (VA) anomalies at the craniovertebral junction (CVJ) in patients with Down syndrome, and characterized the VA anomalies.MethodsThe course of the VA in 46 consecutive patients who were due to undergo posterior arthrodesis surgery at the CVJ were evaluated by three-dimensional CT angiography (3DCTA). Included were five patients with Down syndrome who suffered from myelopathy due to atlantoaxial subluxation. All five patients with Down syndrome also had a simultaneous congenital skeletal anomaly, either os odontoideum or ossiculum terminale.ResultsOf the five patients with Down syndrome, three had VA anomalies at the CVJ, two had fenestration and one had a persistent first intersegmental artery. Of the other 41 patients without Down syndrome, five had VA anomalies at the CVJ. The incidence of VA anomalies at the CVJ was much higher in patients with Down syndrome than in those without Down syndrome.ConclusionIn planning surgery in patients with Down syndrome with symptomatic atlantoaxial subluxation and a congenital skeletal anomaly at the CVJ, we should consider the possible presence of VA anomalies. Preoperative 3DCTA allows us to precisely identify an anomalous VA and evaluate the possible risk of intraoperative VA injury in advance.

Transient paraparesis after laminectomy for thoracic ossification of the posterior longitudinal ligament and ossification of the ligamentum flavum

Study design:Case report.Objectives:To report a case with thoracic myelopathy caused by ossification of the posterior longitudinal ligament (OPLL) and ossification of the ligamentum flavum (OLF), in which postoperative paralysis occurred after laminectomy and was reversed after an additional posterior instrumented fusion.Setting:A University Hospital in Japan.Case report:A 71-year-old woman, with a spastic palsy of both lower extremities, had OPLL and OLF at T10–T11, which pinched the spinal cord anteriorly and posteriorly. She underwent a laminectomy at T10–T11, and no further neurological deterioration was seen immediately after surgery. Over the next 18 h, however, myelopathy worsened, showing severe paraparesis. An additional posterior instrumented fusion at T7–L1 was performed without correction of the kyphosis. After fusion, neurological deficits gradually recovered, despite the presence of residual anterior impingement of spinal cord by the OPLL.Conclusions:The present case provides evidence for the possibility that laminectomy alone produces postoperative paralysis for combined thoracic OPLL and OLF, and we recommend that a posterior instrumented fusion should be added when posterior decompression is performed for this disorder.

Association between serum leptin and bone metabolic markers, and the development of heterotopic ossification of the spinal ligament in female patients with ossification of the posterior longitudinal ligament

Obesity is a risk factor for ossification of the posterior longitudinal ligament (OPLL) of the spine, which is characterized by heterotopic bone formation in the posterior longitudinal spinal ligament. Hyperleptinemia is a common feature of obese people and leptin is believed to be an important factor in the pathogenesis of OPLL. However, the association between leptin and bone metabolism and the development of OPLL is not understood fully. The objective of the present study was to determine the association between serum leptin concentration and bone metabolic markers and the extent of heterotopic ossification of the spinal ligament in patients with OPLL. The serum concentrations of leptin, insulin, fructosamine, bone-specific alkaline phosphatase, and carboxyterminal propeptide of type I procollagen, urine deoxypyridinoline levels, and the number of vertebrae with OPLL involvement were measured in 125 (68 males and 57 females) patients with OPLL. The correlation between leptin and these other factors was then examined. Serum leptin and insulin concentrations were increased significantly in OPLL females compared to non-OPLL female controls. In the females with OPLL, serum leptin concentrations corrected for body mass index correlated positively with the number of vertebrae with OPLL involvement. In females, serum leptin levels were significantly higher in patients in whom OPLL extended to the thoracic and/or lumbar spine than in patients in whom OPLL was limited to the cervical spine. Our results suggest that hyperleptinemia, in combination with hyperinsulinemia, may contribute to the development of heterotopic ossification of the spinal ligament in female patients with OPLL.

Comparison of clinical outcomes between laminoplasty, posterior decompression with instrumented fusion, and anterior decompression with fusion for K-line (–) cervical ossification of the posterior longitudinal ligament

PurposeThe K-line, which is a virtual line that connects the midpoints of the anteroposterior diameter of the spinal canal at C2 and C7 in a plain lateral radiogram, is a useful preoperative predictive indicator for sufficient decompression by laminoplasty (LMP) for ossification of the posterior longitudinal ligament (OPLL). K-line is defined as (+) when the peak of OPLL does not exceed the K-line, and is defined as (–) when the peak of OPLL exceeds the K-line. For patients with K-line (–) OPLL, LMP often results in poor outcome. The aim of the present study was to compare the clinical outcome of LMP, posterior decompression with instrumented fusion (PDF) and anterior decompression and fusion (ADF) for patients with K-line (–) OPLL.MethodsThe present study included patients who underwent surgical treatment including LMP, PDF and ADF for K-line (–) cervical OPLL. We retrospectively compared the clinical outcome of those patients in terms of Japanese Orthopedic Association score (JOA score) recovery rate.ResultsJOA score recovery rate was significantly higher in the ADF group compared with that in the LMP group and the PDF group. The JOA score recovery rate in the PDF group was significantly higher than that in the LMP group.ConclusionsLMP should not be used for K-line (–) cervical OPLL. ADF is one of the suitable surgical treatments for K-line (–) OPLL. Both ADF and PDF are applicable for K-line (–) OPLL according to indications set by each institute and surgical decisions.

Evidence of enhanced expression of osteopontin in spinal hyperostosis of the twy mouse.

Study Design. Gene expression and protein localization of osteopontin (OPN) in spinal hyperostosis of the twy mouse by means of in situ hybridization, immunohistochemistry, and Northern blot analysis. Objective. To verify the involvement of OPN in spinal hyperostosis in the twy mouse and elucidate its ossification pattern at molecular levels. Summary of Background Data. OPN is a molecule that consistently colocalizes with ectopic calcification in human pathologic conditions. The twy mouse, which shows ectopic calcification of the spinal ligament resulting in hind limb paralysis, is considered to be a model for human ossification of the posterior longitudinal ligament of the spine. Methods. Twenty-eight each of age-matched twy, heterozygote, and wild-type mice were killed at 2, 4, 8, 12, and 16 weeks old and subject to histologic and/or molecular analyses. Sections were hybridized with RNA probes for OPN and also stained with anti-OPN antibodies. Total cellular RNA was extracted from the cervicothoracic spine of each genotype at 2- and 16-week-old, and gene expression for OPN and COL10A1 was quantified by Northern blot analysis. Results. Enhanced expression of OPN mRNA was observed in spinal hyperostotic lesions of the twy mouse, specifically in cells of the spinal ligament and chondrogenic cells in the outer layer of the anulus fibrosus. These trends were also confirmed by immunohistochemical analyses. Northern blot analysis showed that a considerable amount of OPN transcripts was detected in all genotypes at 2 weeks old, but the robust expression of OPN mRNA was maintained only in twy mice at 16 weeks old. COL10A1 transcripts were hardly detected regardless of the genotype at 16 weeks old. Conclusion. OPN was overexpressed in the hyperostotic spinal lesions of twy mice, and the hyperostosis was induced mainly by ectopic ossification of the spinal ligament. Because OPN is considered to be an inhibitor of calcification, further studies will be necessary to verify whether OPN overexpressed in the twy mouse is functional.

Multiple neck operations in a patient with severe motor tics because of Tourette’s syndrome: a case report

IntroductionIn patients with Tourette’s syndrome who have severe motor tics, involuntary neck movements can enhance degenerative changes in the cervical spine, occasionally causing myelopathy. There have been a limited number of reports on surgical treatment for cervical myelopathy caused by Tourette’s syndrome, and a consensus for surgical treatment has not been fully established. To the best of our knowledge, this is the first report that describes a case of cervical myelopathy in a patient with Tourette’s syndrome with severe motor tics who has undergone multiple surgeries of the cervical spine.Case presentationA 44-year-old Asian man with severe motor tics due to Tourette’s syndrome presented with cervical myelopathy. Previously, he had undergone an anterior discectomy and spinal fusion with ceramics at the C3-C4 and C5-C6 levels, but required further surgery because of displacement of the ceramics. After the second operation, he developed compression myelopathy at the sandwiched (C4-C5) disc level, and had to undergo a C4-C5 anterior discectomy and spinal fusion, which was unsuccessful.As a salvage operation, we performed a C3-C7 decompression and spinal fusion from both the anterior and posterior approaches. By thorough postoperative external immobilization of his neck, our patient’s spinal fusion was successful and his neurological improvements were maintained for more than 10 years.ConclusionsPatients with Tourette’s syndrome with cervical myelopathy are at risk of having multiple neck operations to correct their symptoms. Postoperative immobilization and the correct selection of surgical procedure are quite important for successful spinal fusion and for avoiding complications at adjacent levels in these patients.