OnabotulinumtoxinA produces significant pain relief in patients with cervical dystonia (CD) treated in US clinical practices, investigators reported on April 22 at the 67th Annual Meeting of the American Academy of Neurology (AAN).
Atul T. Patel, MD, Kansas City Bone and Joint Clinic, Overland Park, Kansas, and colleagues elsewhere presented findings in 508 patients who were treated with onabotulinumtoxinA as part of the Cervical Dystonia Patient Registry for Observation of OnabotulinumtoxinA Efficacy (CD PROBE) study.
Cervical dystonia is the most common form of focal dystonia in adults and is associated with an abnormal head position due to involuntary contraction of muscles in the neck and upper thorax.
Pain is associated with cervical dystonia in approximately 75% of patients and is often among the most disabling features of the disorder.
OnabotulinumtoxinA has been shown to improve such pain in clinical trials but not in a naturalistic setting, Dr. Patel said.
The study included patients who were new to the principal physician’s practice and new to botulinum toxin therapy or, if they had previously participated in a botulinum toxin clinical trial, they must not have received treatment for ≥16 weeks.
Subjects could receive 3 onabotulinumtoxinA treatments. Because individual physicians determined the timing of subsequent treatment sessions, treatment intervals and treatment assessment intervals were variable.
Results showed an increase in pain relief on the Post-Injection Pain questionnaire across all 3 treatment sessions, with significantly more patients reporting pain relief at their final visit than during their first telephone assessment at 2 weeks after their first treatment (78.9% vs 69.1%, respectively, P = .0005).
The mean time to pain relief was 7.0 to 7.5 days.
The mean score on the pain subscale of the Toronto Western Spasmodic Torticollis Rating Scale significantly decreased from 10.4 at baseline to 7.0 at the final visit, (P ˂ .0001).
OnabotulinumtoxinA treatment was also associated with significantly reduced scores on the Pain Numeric Rating Scale and on the pain and discomfort subscale of the Cervical Dystonia Impact Profile-58.