Characteristics and surgical results of the distal type of cervical spondylotic amyotrophy

OBJECT

Cervical spondylosis that causes upper-extremity muscle atrophy without gait disturbance is called cervical spondylotic amyotrophy (CSA). The distal type of CSA is characterized by weakness of the hand muscles. In this retrospective analysis, the authors describe the clinical features of the distal type of CSA and evaluate the results of surgical treatment.

METHODS

The authors performed a retrospective review of 17 consecutive cases involving 16 men and 1 woman (mean age 56.3 years) who underwent surgical treatment for the distal type of CSA. The condition was diagnosed on the basis of cervical spondylosis in the presence of muscle impairment of the upper extremity (intrinsic muscle and/or finger extension muscles) without gait disturbance, and the presence of a compressive lesion involving the anterior horn of the spinal cord, the nerve root at the foramen, or both sites as seen on axial and sagittal views of MRI or CT myelography. The authors assessed spinal cord or nerve root impingement by MRI or CT myelography and evaluated surgical outcomes.

RESULTS

The preoperative duration of symptoms averaged 11.8 months. There were 14 patients with impingement of the anterior horn of the spinal cord and 3 patients with both anterior horn and nerve root impingement. Twelve patients were treated with laminoplasty (plus foraminotomy in 1 case), 3 patients were treated with anterior cervical discectomy and fusion, and 2 patients were treated with posterior spinal fixation. The mean manual muscle testing grade was 2.4 (range 1-4) preoperatively and 3.4 (range 1-5) postoperatively. The surgical results were excellent in 7 patients, good in 2, and fair in 8.

CONCLUSIONS

Most of the patients in this series of cases of the distal type of CSA suffered from impingement of the anterior horn of the spinal cord, and surgical outcome was fair in about half of the cases.

Risk factors for a poor outcome following surgical treatment of cervical spondylotic amyotrophy: a multicenter study

INTRODUCTION

Cervical spondylotic amyotrophy (CSA) is characterized by muscle atrophy in the upper extremities without gait disturbance. However, the indications and outcomes of surgical treatment for CSA have not been clarified. The purpose of this study was to determine the risk factors for a poor outcome following surgical treatment of CSA.

MATERIALS AND METHODS

We performed a retrospective review of CSA in patients from 1991 to 2010 through a multicenter study. We collected information regarding age, type of muscle atrophy, preoperative manual muscle test (MMT), duration of symptoms, high-intensity areas on T2-weighted MR images, low-intensity areas on T1-weighted MR images, levels of spinal canal stenosis, cervical kyphosis and surgical procedures (laminoplasty, anterior cervical discectomy and fusion and posterior spinal fusion), and calculated overall risk factors related to a poor outcome following surgery. Univariate analyses and multivariate logistic regression analysis were performed to identify correlates of a poor outcome.

RESULTS

Fifty-nine patients, 95 % male (56 patients), were included in our analysis with a mean age of 59 years (range 32-78 years). Eighteen patients did not improve after surgery. Symptom duration (OR = 1.263), preoperative MMT grade (OR = 0.169) and distal type of CSA (OR = 9.223) were all associated with an increased risk of a poor surgical outcome.

CONCLUSION

Early surgery is recommended for CSA patients in whom conservative treatment has not been successful. We also recommend surgery for patients who have severe preoperative muscle weakness or have the distal type of CSA.

A histomorphologic study of scoliosis in pinealectomized chickens

STUDY DESIGN

Pinealectomy was used to induce scoliosis in Broiler chickens, and a histologic investigation of the pinealectomized chickens was performed.

OBJECTIVES

To investigate the incidence of scoliosis in pinealectomized Broiler chickens and to determine histologic changes in vertebrae in the pinealectomized chickens before the occurrence of a secondary vertebral wedging deformity due to scoliosis.

SUMMARY OF BACKGROUND DATA

White Leghorn chickens have previously been used as an experimental model of scoliosis, but the occurrence of scoliosis in these chickens following pinealectomy has varied in different reports and is not always high. It is accepted that the development of scoliosis has a close association with growth, but the etiology and mechanism of the disease remain unknown. Histologic findings in vertebrae after the occurrence of scoliosis include those caused by secondary changes due to mechanical compression, and no histologic data for the period before the occurrence of scoliosis are available.

METHODS

Study 1. A total of 100 female "Broiler" chickens were pinealectomized, and the frequency with which scoliosis occurred was investigated. Study 2. Sixty female Broiler chickens were divided into three groups: the control group (Group C, n = 20), the sham operation group (Group S, n = 20), and the pinealectomy group (Group P, n = 20). Each group was then subdivided into two groups according to the time of death: 3 days after the operation (Group 3-C, 3-S, 3-P, n = 10), and 6 days after the operation (Group 6-C, 6-S, 6-P, n = 10). Decalcified thin sagittal sections were made using a tartrate-resistant acid phosphatase (TRAP) stain. Histologic examinations of the growth plate, trabecular structure, and osteoclast number were performed.

RESULTS

The incidence of scoliosis in the pinealectomized Broiler chickens was 93.6%. Nine of the 10 chickens in Group 6-P showed scoliosis deformity, while the presence of scoliosis was unclear in chickens in Group 3-P. The osteoclast number increased significantly in Group 3-P, compared with Groups 3-C and 3-S, and the trabecular thickness was greater in Group 3-P than in Groups 3-C and 3-S. There was no significant change in the growth plate or in other aspects of the trabecular structure, except for trabecular thickness, in any of the groups.

CONCLUSIONS

The results show that the incidence of scoliosis using pinealectomized Broiler chickens is sufficient to study histologic changes of the vertebral body before onset of scoliosis. We found that the osteoclast number and trabecular thickness increased in pinealectomized chickens after 3 days after surgery, just before scoliosis began to develop, and that no change in the growth plate occurred. This suggests that there is no association between changes in the growth plate and the development of scoliosis. However, the change in osteoclast number may have an association with the development of scoliosis, through changes in bone modeling.

Uni-axial cyclic stretch induces the activation of transcription factor nuclear factor kappaB in human fibroblast cells

The effect of uni-axial cyclic mechanical stretch on the activation of the transcription factor nuclear factor kappaB (NF-kappaB) was investigated in a human fibroblast cell line (TIG-1). In response to uni-axial cyclic stretch, NF-kappaB was found to be translocated into the nucleus. The NF-kappaB was first detectable 2 min after the onset of stretch and then peaked at 4 min and returned to the basal level within 10 min. To investigate whether NF-kappaB is activated following the translocation into the nucleus, we measured the luciferase activity in the cells transfected with pNF-kappaB-luciferase. The activity of luciferase increased 4 min after the initiation of cyclic stretch, peaked at 15 min (6.4-fold increase), and decreased gradually. We examined the involvement of the stretch-activated (SA) channel in the stretch-induced NF-kappaB activation. The application of Gd3+, a blocker of the SA channel, or the removal of extracellular Ca2+ inhibited both the translocation into the nucleus and the activation of NF-kB, which suggests that NF-kappaB is activated by uni-axial cyclic stretch via SA channel activation in human lung fibroblasts.

Correlation between the age of pinealectomy and the development of scoliosis in chickens

STUDY DESIGN

Pinealectomy induces experimental scoliosis in chickens. This study analyzed the correlation between the age at which pinealectomy was performed and the development of scoliosis in chickens.

OBJECTIVE

To investigate the differences in the rate or magnitude of scoliosis and the type of curvature in chickens pinealectomized at different times after hatching.

SUMMARY OF BACKGROUND DATA

Scoliosis develops in almost all chickens pinealectomized within 3 days after hatching, but there are no data on whether the condition will develop in chickens pinealectomized earlier or later after hatching.

METHODS

In this study, 106 female white leghorn chickens were divided into six groups: four pinealectomy groups (pinealectomy was performed 2, 4, 11, or 18 days after hatching in Groups P-2, P-4, P-11, and P-18, respectively), a control group (Group C), and a sham operation group (Group S). Ventrodorsal radiographs of the spine were taken at 4-week intervals until the age of 12 weeks. At 12 weeks, a 1-mL sample of blood was taken from the heart at the middle of the dark cycle, and the serum melatonin concentration was measured by radioimmunoassay.

RESULTS

At the age of 12 weeks, scoliosis was present in 63.6% of the chickens in Group P-2, 72.7% in Group P-4, 81% in Group P-11, and 70% in Group P-18, and the Cobb angles in the scoliotic chickens averaged 32.6, 29.8, 23.8, and 22.3 degrees in the respective groups. There were no significant differences in the rate or magnitude of scoliosis and the type of curvature among the pinealectomy groups at the age of 12 weeks. At the age of 12 weeks, the serum melatonin levels at the middle of the dark cycle in the pinealectomized chickens were significantly lower than those of chickens in Groups C and S. However, there were no differences in the serum melatonin levels between scoliotic and nonscoliotic pinealectomized chickens.

CONCLUSIONS

Findings from this study show that scoliosis develops in 60% to 80% of chickens pinealectomized within 18 days after hatching, and that scoliotic development is not influenced by the age at which pinealectomy is performed. However, this study suggests that melatonin plays a complicated role in spinal development, inasmuch as the serum melatonin levels after pinealectomy approximated zero. Yet scoliosis did not develop in all pinealectomized chickens.