T Nomura

Tokai University, Hiratuka, Kanagawa, Japan

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Publications (18)36.02 Total impact

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    ABSTRACT: Intramedullary spinal cord metastasis (ISCM) is a rare complication of cancer. This complication has been studied by magnetic resonance imaging (MRI) more frequently in the clinical context to improve the survival time of cancer patients. However, the number of the reports of its clinical management or radiographic findings is small. To investigate the clinical and imaging characteristics of ISCM, seven cases of ISCM of a nonneurogenic origin were examined retrospectively. Data regarding the site of the primary neoplasm, location of other metastases, initial symptoms, interval from the original diagnosis of cancer to the onset of neurologic symptoms, time course from initial symptoms to urinary retention, MRI data, and outcome after radiologic or surgical intervention were investigated. Five patients had lung cancer metastases, and one each had breast or uterine cancer metastases. The progression of neurologic deficit was rapid, and the average period between the occurrence of initial symptoms and urinary retention was 25 days. The averaged survival period from the diagnosis of ISCM was 5 months in three patients. (One patient is alive, and the data could not be obtained in another three patients.) MRI characteristics were useful for diagnosis, including large high signal intensity areas on T2-weighted images and strong ring or inhomogeneous enhancement on gadopentetate dimeglumine-enhanced T1-weighted images. Surgery was performed on two patients, but total removal could not be achieved. Radiotherapy was effective in treating neurologic deficit in five patients. Surgical treatment is seldom indicated for ISCM, and radiotherapy is recommended as soon as possible after a diagnosis is made from MRI.
    Journal of Spinal Disorders & Techniques 03/2006; 19(1):43-7. · 1.77 Impact Factor
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    ABSTRACT: We reviewed the surgical treatment of 31 patients with burst fractures or teardrop dislocation fractures in the middle and lower cervical spine. Patients were treated with anterior instrumentation, posterior instrumentation, or a combination of both. Patients were evaluated radiographically and with the Frankel neurological outcomes grading scale. Anterior decompression and fusion restored the spinal canal diameter by approximately 60% whereas the posterior or combined approaches restored the canal diameter by only 6%. In addition, nine of 24 patients treated anteriorly gained improved neurological function whereas none of the patients treated posteriorly had neurological improvement. Based on the anatomical and neurological findings, the study demonstrates that anterior fusion is preferable to posterior fusion for the treatment of burst fractures and tear-drop dislocation fractures of the middle and lower cervical spine.
    International Orthopaedics 03/2006; 30(1):54-8. · 2.32 Impact Factor
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    ABSTRACT: A case report of multiple extradural arachnoid cysts at the spinal cord and cauda equina levels in the young. To report an exceedingly rare case of multiple extradural arachnoid cysts at the spinal cord and cauda equina levels in the young. Department of Orthopaedic Surgery, Tokai, Japan. An 11-year-old boy was diagnosed with multiple extradural arachnoid cysts at the spinal cord and cauda equina levels extending from the T5 to L5 vertebrae and surgery was performed. At 2 years after surgery, no recurrence was observed and muscle weakness of the lower extremities and sensory disturbance improved. Excision of only the arachnoid cysts at the spinal cord level led to a favorable outcome.
    Spinal Cord 02/2006; 44(1):59-62. · 1.90 Impact Factor
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    ABSTRACT: Most patients with traumatic spondylolisthesis of the axis are treated nonsurgically. Some patients do not develop symptoms, but others experience strong and persistent neck pain. To clarify the factor that plays a major role in residual neck pain after this fracture, we reviewed nine patients who underwent conservative treatment. Patients were assessed via telephone interviews an average of 62 months after injury and were divided into two groups: those with and those without neck pain. Angulation and anterior translation between the second and third cervical vertebrae were measured on lateral radiograms at the time of injury, removal of brace, and final follow-up. Fracture lines were also investigated by computed tomography. At the time of final follow-up, the average angulation was 6.3 degrees and the average translation was 5.3 mm in the neck-pain group and 0.6 degrees and 0.2 mm, respectively, in the no-symptom group. In patients with fracture lines present on the articular surface of the inferior face joints, angulation persisted or increased, even though the fractures were hemilateral. This was compatible with severe neck pain. In contrast, angulation and translation were improved in patients with an intact inferior articular surface of the axis, and pain was not reported. Injury on the inferior articular surface of the axis may disturb spontaneous healing of C2-C3 subluxation and cause residual neck pain. It is necessary to assess the presence of injury to the inferior facet bilaterally with plain or computed tomograms.
    Journal of Spinal Disorders & Techniques 05/2005; 18(2):148-51. · 1.77 Impact Factor
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    ABSTRACT: Intervertebral disc degeneration is considered to be one of the major causes of low back pain. Despite this irreversible phenomenon, attempts to decelerate disc degeneration using various techniques have been reported. However, to date there has been no proven technique effective for broad clinical application. Based on previous studies, we hypothesize that maintenance of proteoglycan content in the disc is achieved by avoiding the depletion of nucleus pulposus and preserving the structure of the annulus is a primary factor in decelerating disc degeneration. One novel approach to solve the dilemma of intervertebral disc degeneration is found at the stem cell level. Mesenchymal stem cells (MSCs) are known to possess the ability to differentiate into various kinds of cells from mesenchymal origin. Although the majority of cells that contribute to disc formation are known to obtain chondrocyte-like phenotypes, no reported study has emphasized the correlation with mesenchymal stem cells. To evaluate the possible potential of MSCs in disc cell research and treatment of degenerative disc disease, autologous MSCs embedded in Atelocollagen gel were transplanted into the discs of rabbits which had undergone a procedure proven to induce degeneration. The results suggest that MSC transplantation is effective in decelerating disc degeneration in experimental models and provided new hopes for treatment of degenerative disc disease in humans. Atelocollagen gel served as an important carrier of MSCs in transplantation, permitting proliferation, matrix synthesis and differentiation of MSCs. This study strengthens the viable efficacy of practical application of MSCs in treatment of intervertebral disc disease.
    Biomaterials 10/2003; 24(20):3531-41. · 8.31 Impact Factor
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    ABSTRACT: We examined the emergence and sequential changes in type I, II, and VI collagen production in an experimental rabbit model of disc degeneration. Type I collagen was minimally present initially and did not change over 24 weeks. Type I collagen seemed to have no effect on the degenerative process in this model. Staining for type II collagen was positive circumferentially in chondrocytelike cells and was mild in the early phase of disc degeneration, when the chondrocytelike cells began to appear in the inner layers of the annulus fibrosus. The stain became stronger during the middle phase when the chondrocytelike cells arranged themselves in cluster. Compared with type II collagen, the staining for type VI collagen was relatively strong early in the degenerative process. These findings led us to speculate that these chondrocytelike cells play an active role in the degenerative process. The reinsertion of nucleus pulposus cells cocultured with annulus fibrosus delayed disc degeneration and the emergence of chondrocytelike cells. Considering that the emergence of chondrocytelike cells which produce type II and type VI collagen is delayed in discs with the injection of cocultured nucleus pulposus cells by annulus fibrosus cells, we conclude that chondrocytelike cells that produce type VI collagen also seems to accelerate degeneration. Type VI collagen is produced at an earlier phase than type II collagen and may be both active agent and a marker for disc degeneration.
    Connective Tissue Research 02/2003; 44(2):104-8. · 1.79 Impact Factor
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    ABSTRACT: Three case reports of solitary spinal osteochondromas in middle-aged and elderly patients. To describe the treatment of three rare cases of spinal osteochondromas in patients significantly older than the cases previously reported in the literature. Osteochondromas arising in the vertebral column are considered rare. The mean age of clinical appearance is said to be in the second or third decade of life. Clinical history, physical examinations, plain radiographs, magnetic resonance imaging, myelography, computed tomographic myelography, and histopathologic findings for each case were reviewed in conjunction with previous cases reported in the literature. Total removal of the tumor was effective in causing the symptoms to disappear. Spinal osteochondromas are rare and tend to appear in young adults. Three cases of spinal osteochondromas that were unusual in terms of age at clinical presentation and localization were reported, suggesting a continuous growth of the tumor beyond skeletal maturity.
    Spine 01/2003; 27(23):E503-6. · 2.16 Impact Factor
  • Spine Journal - SPINE J. 01/2003; 3(5):101-102.
  • Spine Journal - SPINE J. 01/2003; 3(5):101-101.
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    ABSTRACT: A case report of an upper thoracic spinal subdural hemorrhage which was managed successfully by conservative treatment. Spinal subdural hemorrhage is rare and can cause serious neurologic symptoms. Surgery is the most common treatment and is believed to prevent further neurologic injury. A case of an upper thoracic spinal subdural hemorrhage which was managed successfully by conservative therapy is reported. Department of Orthopaedic Surgery, Tokai University School of Medicine, Isehara, Japan. A 29-year-old woman presented with acute severe back pain. She experienced acutely developed weakness of both lower extremities, hypesthesia below T6 and urinary retention. Magnetic resonance imaging performed on the day of hospital admission revealed the existence of a subdural hematoma in the upper thoracic spine. Muscle strength of the lower extremities was grade 0 on admission, but improved slightly on day 1. The decision was made to manage the patient nonoperatively by corticosteroid and diuretic administration. Improvement was gradual but progressive. Muscle strength was grade 4 out of 5 on the 28th day. Magnetic resonance imaging at 3 months except for mild urinary retention. Spinal subdural hemorrhage can be treated nonoperatively by correlating magnetic resonance image findings with the clinical condition.
    Spinal Cord 01/2002; 39(12):657-61. · 1.90 Impact Factor
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    ABSTRACT: Autogenous implantation of nucleus pulposus or nucleus pulposus cells that were activated by coculture retards intervertebral disc degeneration, but harvesting such grafts causes disc degeneration at the donor site. This study examined whether nucleus pulposus allografts similarly retard disc degeneration and whether such allografting induces immunologic rejection. Japanese White rabbits served as donors and recipients for allografts. Lumbar disc degeneration was induced by aspirating the nucleus pulposus. Two weeks later, intact nucleus pulposus or nucleus pulposus cells were injected and compared with a sham procedure and normal control. The recipients' discs were examined histologically and immunologically at intervals for 16 weeks. Discs receiving an intact nucleus pulposus showed the least degeneration, followed by discs receiving nucleus pulposus cells, both of which were better than no treatment. These findings correlated directly with the intensity of immunochemical staining for Type II collagen. Allogeneic grafts did not induce any appreciable host-versus-graft response. Injection of nucleus pulposus and nucleus pulposus cells retards intervertebral disc degeneration. However, injection of intact nucleus pulposus is more effective than injection of nucleus pulposus cells alone. The intercellular matrix plays an important, but poorly understood, role in preserving intervertebral discs.
    Clinical Orthopaedics and Related Research 09/2001; · 2.79 Impact Factor
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    ABSTRACT: Percutaneous nucleotomy is a relatively new technique for treating lumbar disc herniation. There is no agreement as to the volume of disc material to be removed. A long-term study of clinical and radiological data from patients treated by percutaneous nucleotomy was designed to identify the factors associated with favourable and unfavourable outcomes. We studied 42 patients for at least ten years; the mean follow-up was 10.9 years. They were divided into two subgroups to assess the value of preserving the nucleus pulposus in the central area of the disc. The overall success rate for both subgroups was 50%. A decrease in disc height on plain radiography and a decrease in signal intensity on MRI were observed more infrequently in patients in whom the nucleus pulposus in the central area of the disc had been preserved, than in those in whom it had been extensively removed. These adverse radiological findings correlated closely with increased low back pain during the first one to two years after operation and a poorer overall outcome. We conclude that percutaneous nucleotomy is most likely to be successful when the central area of the disc is preserved.
    Journal of Bone and Joint Surgery - British Volume 06/2001; 83(4):501-5. · 2.69 Impact Factor
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    ABSTRACT: Percutaneous nucleotomy in elite athletes is considered a minimally invasive treatment of lumbar disc herniation. However, long-term effectiveness has not been established by careful follow-up studies. This article evaluates the outcome of percutaneous nucleotomy in elite athletes who have undergone the procedure. Thirty elite athletes with lumbar disc herniation who underwent percutaneous nucleotomy and had been followed for at least 2 years were compared with a matched group of 42 nonathletes. The outcome in athletes was worse than in nonathletes. Early return to vigorous sports activity in less than 3 months correlated with increased symptoms. Similarly, more extensive resection of disc material was associated with an unexpected rapid worsening of the outcome and the lower rate of return to preoperative sports. Patient selection and postoperative management of athletes and nonathletes undergoing percutaneous nucleotomy should be the same, and the procedure in athletes is probably not worthwhile if they do not obey postoperative management such as the timing of return to sports activity.
    Journal of Spinal Disorders 05/2001; 14(2):159-64. · 1.21 Impact Factor
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    Journal of Bone and Joint Surgery-british Volume - J BONE JOINT SURG-BRIT VOL. 01/2001; 83(4):501-505.
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    ABSTRACT: The authors modified the technique of open-door cervical laminoplasty with a patency maintenance method that relies only on soft tissue reconstruction. Thirty-five patients who underwent this procedure were evaluated at more than 2 years' follow-up. The expanded open-door lamina and excellent alignment on the lateral view of the cervical spine were well maintained after surgery. Atrophy of the posterior cervical muscles was not seen. Clinical outcomes were rated satisfactory. Nuchal pain seen in the series of patients who underwent the original expansive open-door laminoplasty or a suspension laminotomy from 1983 to 1993 was decreased in the patients with the modified expansive open-door laminoplasty.
    Journal of Spinal Disorders 11/1999; 12(5):386-91. · 1.21 Impact Factor
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    ABSTRACT: A very rare case of intradural extra-arachnoid schwannoma involving the upper cervical spine is described. The tumour most likely originated from the extra-subarachnoid angle region, with its unusual pattern of expansion within the spinal canal resulting from such characteristics of the upper cervical region as a relatively wide spinal canal, an extensive ventral subarachnoid space, and membranous ventromedian and lateral anchoring structures which influenced the direction of tumour enlargement.
    Spinal Cord 01/1999; 36(12):859-63. · 1.90 Impact Factor
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    ABSTRACT: This study examined the clinical and radiographic results in patients with lumbar disc herniation treated surgically with one of four procedures: two different methods of herniotomy using a posterior approach and two different methods of percutaneous nucleotomy. The authors goal was to identify the structural changes in the disc after each of the procedures and to correlate them with the clinical outcome. The details of herniotomy procedure via a posterior approach or by percutaneous nucleotomy as described by many authors have not been consistent. Furthermore, previous reviews of these studies have been less than satisfactory. One hundred fifty-seven herniotomies using a posterior approach and 94 percutaneous nucleotomies were studied with a follow-up of at least 2 years. Each of these groups was divided into two subgroups to evaluate the role of the remaining nucleus pulposus in the central area of the disc. Changes seen in imaging studies, such as a decrease in disc height and an increase of intervertebral instability in plain radiographs and a decrease in signal intensity of the disc in magnetic resonance images, were significantly less common in the subgroups of herniotomy and percutaneous nucleotomy in which the nucleus pulposus in the central area of the disc was preserved when compared with the subgroups in which a complete removal of the disc was attempted. The changes seen in the imaging studies were significant in patients younger than 40 years of age and correlated closely with the clinical results. Preserving the nucleus pulposus during the surgical treatment of lumbar disc herniation in patients younger than 40 years of age resulted in better radiographic and clinical results.
    Spine 08/1996; 21(13):1556-63; discussion 1563-4. · 2.16 Impact Factor
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    ABSTRACT: Patients in percutaneous nucleotomy who met our new criteria for patient selection in 1992 showed 73% successful results. The success rate was not satisfactory in comparison with that (88%) in the open surgery through posterior approach (herniotomy), however. The purpose of this report is to re-evaluate 70 patients with follow-up more than 2 years based on imaging and clinical findings before percutaneous nucleotomy. In results, supplementary criteria such as two types of the combination of computed tomography discogram and computed tomography myelogram, continuation of the contrast medium in lateral view of discogram, and clinical findings characterized by sciatic pain were obtained to improve the success rate. Eighty-one percent of patients who met the new criteria in 1992 and the supplementary criteria were identified in the successful group. The authors believe that percutaneous nucleotomy should be considered as an independent operative procedure with results similar to open surgery, if the patient is selected strictly based on these criteria and supplementary criteria.
    Spine 12/1993; 18(15):2212-7. · 2.16 Impact Factor