Loss Of Inhibition Research Articles

Selective cervical dorsal rhizotomy to relieve upper-limb spasticity after stroke or spinal cord injury - Report of five cases

Objective: Myelopathy is the most serious sequela after central nervous system insult. Due to loss of inhibition from upper neurons, hyperreflexia, spasticity, cramping pain, and paresthesia are typically noted with numbness over the limbs. Severity of spasticity is measured with the modified Ashworth scale (MAS). For patients with low-grade spasticity (MAS 1, 1+, and 2), oral medication, physical therapy, and occupational therapy can provide satisfactory results. However, for patients with high-grade spasticity (MAS 3 and 4), adjuvant therapies, such as selective dorsal rhizotomy, are needed. Materials and Methods: Since 2001, we have used selective cervical dorsal rhizotomy in Taiwan for eight spastic upper limbs in five patients. A posterior approach to the spinal canal is made under general anesthesia. After opening the dura, the selected roots are identified with anatomic landmarks and confirmed with intraoperative nerve-root stimulation. Two dorsal roots (C-5, C-6) are selected for spasticity of the upper arm, whereas C-7, C- 8, and T-l are selected for spasticity of the forearm and hand. A 50% to 80% mechanical section is performed one by one for each root. Results: At the 3 month follow-up, reduction of mean MAS grade from 3.5 to 1+ was demonstrated (p 0.008). Spasticity of both elbow and wrist joints was reduced by C-7, C-8 and T-1 dorsal rhizotomy. Conclusions: In our experience with a limited number of patients, selective cervical dorsal rhizotomy relieves upper-limb spasticity after central nervous system insults such as stroke or spinal cord injury.