Use of botulinum toxin-A for musculoskeletal pain in patients with whiplash associated disorders [ISRCTN68653575].

Background: Whiplash associated disorder is commonly linked to motor vehicle accidents and sports injuries. Cervical injury is attributed to rapid extension followed by neck flexion. The exact pathophysiology of whiplash is uncertain but probably involves some degree of aberrant muscle spasms and may produce a wide range of symptoms. The most commonly prescribed pharmacological agents for initial treatment of whiplash-associated pain are oral muscle relaxants and nonsteroidal anti-inflammatory drugs. However, potential systemic adverse effects limit these agents. Physical interventions such as mobilization, manipulation, and exercises have proved beneficial for pain and dysfunction but only on a time-limited basis. Little evidence suggests that physical therapy specifically aimed at the musculature (e.g., transcutaneous electrical nerve stimulation, ultrasonography, heat, ice, and acupuncture) improves prognosis in acute whiplash associated disorder. A new approach to treatment is the use of botulinum toxin, which acts to reduce muscle spasms.

Methods/design: This is a prospective, randomized, controlled clinical trial and botulinum toxin-A (Botox) injections will be compared with placebo injections. The primary objective is to determine the efficacy of Botox in the management of musculoskeletal pain in whiplash associated disorders.

Discussion: Botulinum toxin type-A toxin has been studied in small trials on whiplash associated disorder patients and has generally been found to relieve pain and improve range of motion. Specifically, we seek to assess the efficacy of Botox in reducing pain and to improve the cervical spine range of movement, during the 6-month trial period.