Dystonia is a network disorder involving the motor cortex, premotor cortex, and their connections with other brain regions. Currently, the standard treatment for dystonia is botulinum toxin (BoNT) injections administered every 12 weeks to affected muscle groups, and invasive treatments include Deep Brain Stimulation (DBS). Botox injections can be painful and the benefits usually don’t last, while DBS is an invasive procedure, and not all patients are appropriate candidates for the surgery. Hence, using a non-invasive technique such as Repetitive Transcranial Magnetic Stimulation (rTMS) to prolong and potentiate the benefits of BoNT therapy can be helpful as a potential treatment for cervical dystonia.
Transcranial magnetic stimulation (TMS) is a painless and non-invasive neuromodulation technique that uses a magnetic field to induce an electric field in the cortex. TMS pulses delivered on a repetitive basis known as repetitive TMS (rTMS) have the ability to modulate dystonia networks and lead to clinical improvements. The primary goal of the proposed study is to determine whether low-frequency rTMS delivered to the dPMC has synergism with BoNT therapy in patients with isolated cervical dystonia. As the rTMS therapy requires multiple sessions spanning weeks for cumulative benefits, feasibility and compliance for completion of therapy can be challenging. We, therefore are utilizing an accelerated rTMS protocol that will condense multiple sessions into 4 consecutive days. Accelerated rTMS has been successful in other patient populations but has not been studied in dystonia yet. We will determine whether rTMS serves as a therapeutic bridge for the early fading of BoNT benefits, along with the investigation of physiological changes underlying the clinical effects of this treatment protocol.