Cold Allodynia after C2 Root Resection in Sprague-Dawley Rats

OBJECTIVE: The purpose of this study was to evaluate pain-related behaviors after bilateral C2 root resection and change in pain patterns in the suboccipital region in rats.METHODS: Male Sprague-Dawley rats were randomly assigned to three groups (n=25/group); näive, sham, and C2 resection. Three, 7, 10, and 14 days after surgery, cold allodynia was assessed using 20 μL of 99.7% acetone. c-Fos and c-Jun were immunohistochemically stained to evaluate activation of dorsal horn gray matter in C2 segments of the spinal cord 2 hours, 1 day, 7 days, and 14 days after surgery.RESULTS: Three days after surgery, the response to acetone in the sham group was significantly greater than in the näive group, and this significant difference between the näive and sham groups was maintained throughout the experimental period (p < 0.05 at 3, 7, 10, and 14 days). Seven, 10, and 14 days after surgery, the C2 root resection group exhibited a significantly greater response to acetone than the näive group (p < 0.05), and both the sham and C2 resection groups exhibited significantly greater responses to acetone compared with 3 days after surgery. No significant difference in cold allodynia was observed between the sham and C2 root resection groups throughout the experimental period. Two hours after surgery, both the sham and C2 root resection groups exhibited significant increases in c-Fos- and c-Jun-positive neurons compared with the naive group (p=0.0021 and p=0.0358 for the sham group, and p=0.0135 and p=0.014 for the C2 root resection group, respectively). One day after surgery, both the sham and C2 root resection groups exhibited significant decreases in c-Fos -positive neurons compared with two hours after surgery (p=0.0169 and p=0.0123, respectively), and these significant decreases in c-Fos immunoreactivity were maintained in both the sham and C2 root resection groups 7 and 14 days after surgery. The sham and C2 root resection groups presented a tendency toward a decrease in c-Jun-positive neurons 1, 7, and 14 days after surgery, but the decrease did not reach statistical significance.CONCLUSION: We found no significant difference in cold allodynia and the early expression of c-Fos and c-Jun between the sham and C2 resection groups. Our results may support the routine resection of the C2 nerve root for posterior C1–2 fusion, but, further studies are needed.

Cold Allodynia after C2 Root Resection in Sprague-Dawley Rats

OBJECTIVE: The purpose of this study was to evaluate pain-related behaviors after bilateral C2 root resection and change in pain patterns in the suboccipital region in rats. METHODS: Male Sprague-Dawley rats were randomly assigned to three groups (n=25/group); näive, sham, and C2 resection. Three, 7, 10, and 14 days after surgery, cold allodynia was assessed using 20 μL of 99.7% acetone. c-Fos and c-Jun were immunohistochemically stained to evaluate activation of dorsal horn gray matter in C2 segments of the spinal cord 2 hours, 1 day, 7 days, and 14 days after surgery.

Spinal Subdural Hematoma Following Cranial Subdural Hematoma : A Case Report with a Literature Review

Coexistence of cranial and spinal subdural hematomas is rare and only a few cases have been reported in the literature. Herein, we report a case of cranial and spinal subdural hematomas after previous head trauma. As the pathogenesis of simultaneous intracranial and spinal subdural hematoma yet remains unclear, we developed an alternative theory to those proposed in the literature for their coexistence, the migration of blood through the subdural space.

A Concealed Disc Fragment under the Peridural Membrane

A herniated lumbar disc is a very common disease of the spine. However, not all of the disc fragments are located at the expected site. In particular, the ventral epidural space contains many hidden compartments with the potential to hold herniated disc material. We encountered a case of a concealed disc under the peridural membrane, which was very difficult to be identified. The peridural membrane, which is situated below the posterior longitudinal ligament, is a thin glossy membrane surrounding the entire spinal bony canal. The peridural membrane is attached loosely to the median bony septum but not to other part of vertebral body. This potential space between the peridural membrane and bare bone of the vertebral body is called the premembranous space. We report this case to introduce a potential space for disc migration and emphasize the need for a good understanding of the epidural microanatomy.