遠藤 照顕

Objective Ossification of the ligamentum flavum (OLF) is rarely identified in cervical spine and its pathogenesis has not been established. We report a case of multiple-level OLF, combined with the calcification of the cervical ligamentum flavum and posterior atlanto-axial membrane. Clinical presentation A 42-year-old man without any systemic background presented with one month history of pain from the neck to the right shoulder and right leg numbness. Cervical computed tomography demonstrated OLF from C2 to C5, a small area of calcification of the ligamentum flavum (CLF) from C5/6 to C7/T1 and extensive calcification of the posterior atlanto-axial membrane, resulting in spinal canal stenosis. Magnetic resonance imaging showed spinal canal stenosis and severe spinal cord compression from C2 to C5. Thoracic X-ray also showed ossification of the posterior longitudinal ligament (OPLL). We performed laminectomy from C1 to C5 and resected the calcified posterior atlanto-axial membrane and OLF. Histopathological examination demonstrated calcified granules within degenerated fibrous tissue in the posterior atlanto-axial membrane and mature bony trabeculae, bone marrow and residual ligament tissue in the OLF. Conclusions Simultaneous development of cervical OLF and CLF in this case seems unlikely to have occurred coincidentally and suggests that the pathogenesis of OLF and CLF may share a common initiation factor. © Springer-Verlag Berlin Heidelberg 2012.

Purpose: To test the usefulness of a novel performance test, the tally counter test (counter test), which uses a hand tally counter to objectively assess the severity of cervical myelopathy. Methods: Eighty-three patients with compressive cervical myelopathy (mean age 64 ± 13 years) who were undergoing cervical laminoplasty and 280 healthy control subjects (aged 20-89 years) were tested. The subjects were instructed to push the button of a tally counter as many times as possible in 10 s. The average of the right- and left-sided values in each patient was used for analysis. In the patient group, counter test values were compared with Japanese Orthopaedic Association (JOA) and Japanese version of the 36-Item Short Form Health Survey scores preoperatively and 12 months postoperatively. Results: The average counter test value was significantly lower in patients with myelopathy than age- and gender-matched controls (32.9 ± 10.9 vs. 46.9 ± 8.5, P &lt 0.0001). The counter test value was significantly higher at 2 weeks postoperatively than preoperatively (P = 0.0014). Counter test values showed a moderate correlation with JOA scores and a weak to moderate correlation with SF-36 physical functioning, role functioning, and role-emotional scores both pre- and postoperatively. The intraclass correlation coefficient of counter test values was high both pre- and postoperatively. Conclusion: The tally counter test is objective and quantitative assessment method for patients with cervical myelopathy. The test is simple, reliable, and capable of detecting small functional changes. © 2012 Springer-Verlag Berlin Heidelberg.

Pulsatile movements of the dura mater have been interpreted as a sign that the cord is free within the subarachnoid space, with no extrinsic compression. However, the association between restoration of pulsation and adequate decompression of the spinal cord has not been established. The present study investigated the relationship between the extent of spinal cord decompression and spinal cord and dural pulsations based on quantitative analysis of intraoperative ultrasonography (US). Eighty-five consecutive patients (55 males, 30 females; mean age, 64 +/- A 13 years) who underwent cervical double-door laminoplasty to relieve compressive myelopathy were enrolled. Spinal cord decompression status was classified as: Type 1 (non-contact), the subarachnoid space was retained on the ventral side of the cord, Type 2 (contact and apart), the cord showed both contact with and separation from the anterior element of the cervical spine, or Type 3 (contact), the cord showed continuous contact with the anterior element of the cervical spine. Spinal cord and dura mater dynamics were quantitatively analyzed using automatic video-tracking software. Furthermore, the intensity of spinal and dural pulsation was compared with the recovery of motor function at 1 year after surgery as measured by increase in the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ). Spinal cord pulsation amplitude ranged from 0.01 to 0.84 mm (mean 0.30 +/- A 0.16 mm) and dural pulsation amplitude ranged from 0.01 to 0.38 mm (mean 0.14 +/- A 0.08 mm). Average spinal cord pulsation amplitude in Type 2 patients was significantly larger than that in the other groups, whereas, average dural pulsation amplitudes were similar for all three groups. There was a significant correlation between spinal cord and dural pulsation amplitudes in Type 1 patients, but not in Type 2 or Type 3 patients. Type 3 patients showed a particularly poor correlation between spinal cord and dural pulsations. Spinal cord pulsation amplitude was moderately correlated with the recovery of motor function evaluated by JOACMEQ. The present results suggest that restoration of dural pulsation is not an adequate indicator of sufficient decompression of the spinal cord following a surgical procedure.

Study Design. Observational anatomic study. Objective. To give precise information on the surgical anatomy of the medial branches of the cervical dorsal rami. Summary of Background Data. The anatomy of the medial branches has not been sufficiently described. Methods. We recorded the location of the medial branches in 94 consecutive patients who underwent laminoplasty for cervical compression myelopathy. A posterior cervical approach was made along the edge of the nuchal ligament, and, after carefully detaching the trapezius muscle from the nuchal ligament; we identified the right-side branches around the semispinalis capitis muscle. We recorded the location of the branches with reference to the spinous processes and the semispinalis capitis and trapezius muscles. In 52 patients, we electrically stimulated the branches and observed the contraction of these muscles. Results. Branches were identified between C3 and C6 spinous process levels in 92 patients. A single branch was identified in 56 patients, 2 branches were identified in 35 patients, and 3 branches were identified in the remaining 1 patient. Branches were located between C3 and C4 (n = 12), between C4 and C5 (n = 80), between C5 and C6 (n = 2), and at C6 (n = 35). There were 4 patterns of final course: 52 branches passed through the medial side of the semispinalis capitis and trapezius muscles and terminated in a subcutaneous area; 50 branches penetrated the semispinalis capitis and trapezius muscles and terminated in a subcutaneous area; 12 branches terminated in the semispinalis capitis muscle; and 15 branches penetrated the semispinalis capitis and terminated at the nuchal ligament. In 19 of 52 patients tested, the semispinalis capitis muscle contracted after electrical stimulation. Conclusion. Medial branches of the cervical dorsal rami were discernible in cervical posterior approach laminoplasty and were frequently found adjacent to C4 and C5 spinous processes. The medial branches sometimes supplied motor fibers to the semispinalis capitis muscle. Knowledge of the course of these branches might be helpful for avoiding injury during laminoplasty.

Rehabilitation is important for the functional recovery of patients with spinal cord injury. However, neurological events associated with rehabilitation remain unclear, Herein, we investigated neuronal regeneration and exercise following spinal cord injury, and found that assisted stepping exercise of spinal cord injured rats in the inflammatory phase causes allodynia, Sprague-Dawley rats with thoracic spinal cord contusion injury were Subjected to assisted stepping exercise 7 clays following injury. Exercise promoted microscopic recovery of corticospinal tract neurons, but the paw withdrawal threshold decreased and C fibers had aberrantly sprouted, suggesting a potential cause of the allodynia. Tropomyosin-related kinase B (TrkB) receptor for brain-derived neurotrophic factor (BDNF) was expressed on aberrantly sprouted C-fibers. Blocking of BDNF-TrkB signaling markedly suppressed aberrant sprouting and decreased the paw withdrawal threshold. Thus, early rehabilitation for spinal cord injury may cause allodynia with aberrant Sprouting of C-fibers through BDNF-TrkB signaling. (C) 2009 Elsevier Inc. All rights reserved.