Sometimes. Zaneflex is indicated for muscle spasticity due to MS or spinal cord injuries. It has been found to help with dystonias (20%). The most commonly used muscle relaxant is baclofen. Side effects include sedation, infrequent tolerance, and dysphoria - depressive mood.
Yes. Muscle relaxers with central brain effects like tizanadine can be helpful. Other treatments include botulinum toxins by injection. See a physiatrist or neurlogist for eligibility.