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N Furusawa

Publications and source records attributed to N Furusawa.

At least 55 records · Page 3Linked to original sources

Plasticity of the spinal cord contributes to neurological improvement after treatment by cervical decompression. A magnetic resonance imaging study.

To investigate the relationship between morphological plasticity of the spinal cord and neurological outcome after surgery for compressive lesions, we correlated the transverse area of the cervical spinal cord measured by transaxial magnetic resonance imaging (MRI) obtained during the early postoperative period (1-6 months) with neurological function assessed at a median postoperative follow-up period of 2.5 years. Measurements on MRI in 56 patients (35 men and 21 women) included evaluation of the cross-sectional area of the cervical cord and the subarachnoidal space at the level of decompression. The transverse area of the cervical cord increased by 30 to 62% postoperatively and that of the subarachnoidal space by 57 to 95%. Neurological improvement was noted in all patients and averaged 63% in our assessment scale. Expansion of the cervical cord during the early postoperative period correlated significantly with the late postoperative neurological status (P = 0.009). Our results suggest that an increase in the cross-sectional area of the cervical spinal cord, representing spinal cord morphological plasticity, is a significant factor in determining the late neurological improvement following decompressive surgery.

Adult↗

Ganglion cyst of the posterior longitudinal ligament causing lumbar radiculopathy: case report.

We describe a man aged 26 years who presented with a neurological syndrome, which was found on lumbar radioculopathy to be due to a ganglion cyst originating from the posterior longitudinal ligament. Based on MRI findings, cystic lesion was suspected, a round lesion at L4 level with no connection to the adjacent facet or to the dura matter. During surgery, a liquid-containing cystic lesion was found to originate from the posterior longitudinal ligament at L4 level. The resected cyst was diagnosed histologically as a ganglion cyst. A complete cure was established after surgery and no recurrence was noted at a follow-up 1.7 years postoperatively. A ganglion cyst of the posterior longitudinal ligament should be considered in the differential diagnosis of a cyst in the lumbar region causing neurological complications.

Adult↗

Three-dimensional computed tomography for evaluation of cervical spinal canal enlargement after en bloc open-door laminoplasty.

We evaluated the use of three-dimensional (spiral) computed tomography (CT) to assess widening of the bony cervical spinal canal following en bloc open-door C3-C7 laminoplasty in 31 patients. Measurements were performed using a computerised image processing system. The increment in the anteroposterior spinal canal axis and volume of the bony spinal canal was investigated in relation to changes in cervical spine lordosis as well as postoperative neurological improvement. Neurological follow-up averaged 2.6 years (range, 1 to 7 years). A mean increase of 42% was observed in the anteroposterior axis of the canal between C3 to C7 after surgery, while the volume increased by 45%. Postoperatively, cervical spine lordosis correlated with increments in the volume of the enlarged bony canal rather than the anteroposterior axis. Postoperative neurological improvement correlated significantly with the increase in the canal volume. Our results indicate that spiral CT is useful for the assessment of the magnitude of cervical canal enlargement and evaluating the space available for the spinal cord following the relief of compression.

Adult↗

Extraforaminal lumbar disc herniation at two contiguous intervertebral levels.

We describe two unusual surgical cases who presented with extraforaminal lumbar disc herniation that occurred at two adjacent vertebral levels simultaneously and unilaterally. Magnetic resonance imaging and selective nerve root infiltration followed by radiculography helped to outline the herniated disc material. Lateral fenestration and microsurgical foraminal widening of the affected vertebral levels allowed a complete and safe relief of the compressed nerves.

Female↗

Potential role of streptozotocin in enhancing ossification of the posterior longitudinal ligament of the cervical spine in the hereditary spinal hyperostotic mouse (twy/twy).

We investigated the effects of streptozotocin-induced diabetes mellitus on ossification of the posterior longitudinal ligament (OPLL) in the murine cervical spine. A genetically-bound spinal hyperostotic mouse, the tip-toe walking Yoshimura (twy) mouse, was used in these experiments. Histological examination showed that streptozotocin enhanced membranous and enchondral ossification of the posterior longitudinal ligament of the cervical spine, particularly in the area of the ligamentous enthesis. It also increased the number of alkaline phosphatase-positive osteoblast-like mesenchymal cells particularly around the enthesis, while the number of such cells was less in control twy mice and ICR mice treated with streptozotocin. The area of OPLL subsequently increased in size in streptozotocin-treated twy mice. We suggest that streptozotocin-induced diabetes enhances OPLL in the genetically-bound spinal hyperostotic mouse (twy/twy).

Age Factors↗

Herniated cervical intervertebral discs: histological and immunohistochemical characteristics.

We examined the histological and immunohistochemical changes within and around herniated cervical intervertebral discs. A total of 28 herniated discs were harvested en bloc during anterior decompressive surgeries and examined together with the surrounding tissues. The presence of herniated discs correlated with the degeneration of cartilaginous endplate and torn annulus fibrosus. Formation of new blood vessels around the herniated discs was detected, using von Willebrand factor antibody, in seven (25% of all) uncontained hernias and eight (38%) contained hernias. Immunohistochemical studies using specific antibodies showed the presence of cells positive for matrix metalloproteinase-3 (chondrocytes), CD68 (macrophages and monocytes), and interleukin-1 beta (endothelial cells), in cervical disc hernias. Our results suggested that the magnitude and degree of immunohistochemical tissue reaction in cervical disc herniation correlate with the extent as well as location of herniated disc material.

Adult↗

Lordotic alignment and posterior migration of the spinal cord following en bloc open-door laminoplasty for cervical myelopathy: a magnetic resonance imaging study.

We investigated lordotic alignment and posterior migration of the spinal cord following en bloc open-door laminoplasty for cervical myelopathy. Fifty-five patients (32 men and 23 women) were studied, with an average follow-up of 2.4 years. Radiological examination included evaluation of lordosis of the cervical spine and spinal cord, degree of enlargement of bony spinal canal, and the magnitude of posterior cord migration. We also correlated these changes with neurological improvement. Postoperatively, there was an average of 5% loss of cervical spine lordosis (P > 0.01) on radiographs and 12% reduction in the lordotic alignment of the spinal cord (P > 0.05) on magnetic resonance imaging. Postoperatively, the size of the bony spinal canal increased by 48%. Posterior cord migration showed a significant correlation with the preoperative cervical spine and spinal cord lordosis (P < 0.05). Thirty-seven (67%) patients with neurological improvement exceeding 50% showed significant posterior cord migration following laminoplasty compared with those demonstrating less than 50% improvement (P = 0.01). Our results suggest that a significant neurological improvement is associated with posterior cord migration after cervical laminoplasty.

Adult↗

Microsurgical nerve root canal widening without fusion for lumbosacral intervertebral foraminal stenosis: technical notes and early results.

We describe a technique for microsurgical widening of the nerve root canal in the lumbosacral spine. We also report our early results in 31 patients (19 men and 12 women; average follow-up, 3.2 years) with such foraminal stenosis but without osseous defects in the pars interarticularis and/or spondylolisthesis. The affected nerve root was decompressed by interlaminar medial foraminotomy followed by lateral laminotomy and foraminotomy using a microsurgical technique. The procedure aimed at preserving bony continuity of the pars interarticularis and segmental motion. Neurological results showed a favourable improvement of radicular symptoms and of intermittent claudication. The need for segmental fusion at the operated segment was excluded in 30 patients, but one patient subsequently required a transpedicular screw procedure with bone grafting. We recommend the present technique for effective decompression of the nerve root within the neural foramen, simultaneously maintaining lumbar spine mobile function.

Action Potentials↗

Posterior limbus vertebral lesions causing lumbosacral radiculopathy and the cauda equina syndrome.

This report reviews our experience with spinal decompression for posterior limbus vertebral lesions or osteocartilaginous vertebral corner defects in the lumbar spine in 29 children and young adults. There were 19 male and 10 female patients with a mean age of 16.5 years (range, 9 to 24 years). Twenty-four patients were involved with various athletic activities. Clinical presentation included low back pain with a variable degree of radiculopathy in 25 patients and a cauda equina syndrome in four. The level of the affected spinal area was L1-2 in one patient, L2-3 in one, L3-4 in seven, L4-5 in 17, and L5-S1 in three. The preoperative imaging workup showed lateralised "non-calcified' or 'calcified' limbus vertebral defects in 13 patients and centrally displaced lesions in 16 patients. All patients underwent posterior spinal decompression with a slightly extended laminotomy, except for three patients who had a subsequent posterolateral fusion. All of the patients consequently returned to practice their favourite preoperative sport and lifestyle, but five discontinued their previous sports. We suggest that patients with posterior limbus vertebral lesions require careful diagnosis and therapy that are different from those with an ordinary lumbar disc herniation.

Adolescent↗

Depletion of dietary sulphamonomethoxine and sulphadimethoxine from various tissues of laying hens.

Sulphamonomethoxine (SMM) or sulphadimethoxine (SDM) was fed to laying hens at 400 mg/kg diet for 5 successive days. After withdrawal of the drugs, contents (mg/kg) of SMM and SDM in the blood, kidney, liver, ovary, muscle and adipose tissue were determined by HPLC. 2. The disappearance of dietary SMM and SDM from the tissues of laying hens was rapid and, except for the liver, was very similar in all tissues. 3. A common biological half-life (t1/2) of SMM in the above 6 tissues was estimated to be 5.2 h. The t1/2 of SDM in the liver was 6.9 h, significantly longer than that of 4.4 h in the other 5 tissues. The values were much shorter than 51/2 (reported elsewhere) for other drugs. 4. Comparing the data found in this study with those obtained from previous papers, the depletion velocities of SMM and SDM from the hen's body were much faster than those from albumen in egg. The reason for this is probably related to the longer time period over which albumen formation occurs.

Adipose Tissue↗

Characteristics and mechanism of the ossification of posterior longitudinal ligament in the tip-toe walking Yoshimura (twy) mouse.

To elucidate the mechanism of ossification of the posterior longitudinal ligament (OPLL), we examined the serial changes in the intervertebral disc of tip-toe walking Yoshimura (twy) mouse. At the age of 6 weeks, the volume of the nucleus pulposus increased in all intervertebral discs causing anterior and posterior herniation. Secondary to this herniation, the cartilagineous tissue of the annulus fibrosus was disrupted and showed regenerative proliferation with PCNA-positive cartilagineous cells. These cells were S-100 positive and the matrix was positive for chondroitin-4-sulfate proteoglycan, indicating the development of calcification. At the age of 15 weeks, the regenerative cartilagineous tissue of the annulus fibrosus reached the posterior longitudinal ligament together with neovascularization and appearance of PCNA-positive proliferating primitive mesenchymal cells. These cells were considered to be osteoblasts since they were positive for alkaline phosphatase and the matrix contained type I collagen. Using electron microscopic X-ray analysis, vesicles present in the matrix of regenerative cartilagineous cells of the annulus fibrosus were confirmed to contain calcium phosphate crystals, also indicating the development of calcification. In conclusion, our serial analysis indicates that ossification of posterior longitudinal ligament in twy mouse was triggered by enlargement of the nucleus pulposus followed by herniation, disruption and regenerative proliferation of annulus fibrosus cartilagineous tissues. Enchondral ossification of the new annulus fibrosus cartilagineous cells and membraneous ossification by primitive osteoblasts proceed to the final ossification of the posterior longitudinal ligaments.

Alkaline Phosphatase↗

Flexibility and alignment of the cervical spine after laminoplasty for spondylotic myelopathy. A radiographic study.

The long term effects of laminoplasty on cervical movement and alignment were investigated by radiography and CT scans in a study of 56 patients with multisegmental myelopathy who had undergone a C3 to C7 open-door laminoplasty. Follow up averaged 5.8 years. Satisfactory neurological improvement occurred in 73%. Cervical flexion decreased by 35% and extension by 57%; the decrease of both movements was statistically significant. Decreased vertebral slip, as well as slightly reduced lordosis, was seen after operation. Increase in measured canal size after operation and at follow up was 48% and 40%; 8% of the expanded canal size was lost at the last follow up. Expansive open-door laminoplasty leads to a better neurological prognosis in this group of patients, while maintaining an increase in canal size and preserving spinal stability.

Aged↗

Lumbar radiculopathy associated with anterior intraspinal bony lesions.

Thirty-one patients underwent posterior decompression for anterior intraspinal bony lesions which were causing symptoms. The diagnoses were a displaced apophyseal endplate, vertebral corner bulge, and an ossified posterior longitudinal ligament or disc. Symptoms were caused by associated lumbar disc herniations or by gradual impingement by the bony lesion on neural tissue. The success rate after operation was 84%. Anterior spinal canal compromise by bony lesions can be treated by decompression through a posterior approach with minimal destruction of the laminae and facets.

Adult↗

The cervical spine in the Klippel-Feil syndrome. A report of 57 cases.

We report 57 cases of the Klippel-Feil syndrome. Five had type I congenital cervical fusion, 48 type II and 4 type III. The symptoms and signs varied considerably. Patients with C2-C3 fusion often had symptoms associated with odontoid dysplasia and occipito-cervical instability. Twenty-one had progressive neurological symptoms and 19 were operated on: 3 had occiput-C3 posterior arthrodeses, 2 a single level fusion, 1 a laminectomy and anterior arthrodesis, and 13 had laminoplasties. Degenerative changes at the unfused segment and a narrow bony canal are high risk factors in the development of neurological compromise.

Adolescent↗

The role of calcium deposition in the ligamentum flavum causing a cauda equina syndrome and lumbar radiculopathy.

Our report concerns five patients who underwent lumbar decompressive surgery for cauda equina syndrome and radiculopathy secondary to degenerative stenosis associated with calcium deposition in the ligamentum flavum. The resected ligamentum flavum showed diffuse to massive calcium crystal deposition with a histologically marked degeneration in the elastic fibres. Energy dispensive radiographic microanalysis confirmed the crystal to be calcium pyrophosphate dihydrate in all patients, hydroxyapatite mixed in three and calcium orthophosphate mixed in one. The deposition appeared to be a change that is associated with the degenerative process in the ligament and, in some cases having marked deposition in a localised event, it causes or aggravates the neurological symptoms.

Aged↗

Anterior decompressive surgery for cervical ossified posterior longitudinal ligament causing myeloradiculopathy.

This paper reviews 88 patients (74 males and 14 females) who underwent anterior decompression and fusion for symptomatic ossified posterior longitudinal ligament of the cervical spine. Follow up averaged 8.5 years. Eighteen patients underwent one-vertebra, 59 two-vertebra, and 11 three-vertebra decompression with interbody fusion. The preoperative severity of symptoms significantly affected neurological recovery. Patients with three-vertebra spondylectomy showed significantly little neurological improvement. The return of patients to their previous activities as monitored at follow up was related to their preoperative neurological status. MRI findings appeared to be relevant to neurological recovery. Our findings suggest that anterior decompression is to be recommended for patients with less advanced preoperative symptoms and the involvement of one or two vertebrae.

Activities of Daily Living↗

Cervical laminoplasty in patients with ossification of the posterior longitudinal ligaments.

Cervical laminoplasty was the operation used for myeloradiculopathy secondary to ossification of the posterior longitudinal ligaments. Some 57 patients were followed up for 5-13 years (average: 7.8 years). The spinal canal from C3 to C7 was surgically opened en bloc unilaterally with spacer bone grafting to maintain the laminae in a 'kept open' position and thus to implement posterior decompression. No serious major surgery-related complications were observed. Favourable results were obtained in 42 patients (74%), but those with advanced preoperative neurological symptoms did not improve. Patients with spinal canals seriously compromised by anterior ossified lesions recovered poorly. We concluded that laminoplasty is recommended for cervical myeloradiculopathy due to ossified posterior longitudinal ligaments for selected patients, but surgery should be done before the patient has developed serious neurological damage.

Aged↗