Efficacy of Botulinum toxin and Repetitive Transcranial Magnetic Stimulation in treating Cervical Dystonia: A Double-blind Placebo Controlled Trial

INTERVENTION: repetitive Transcranial Magnetic Stimulation (rTMS) given in addition to botulinum toxin treatment given in accordance with clinical need. We will use repetitive Transcranial Magnetic Stimulation (rTMS) parameters demonstrated to have a clinical benefit in a previous case study in cervical dystonia. This will consist of stimulation over the premotor cortex contra lateral to the overactive sternoceidomastoid muscle, 2.5cm anterior to the optimal scalp position for activation of 1st dorsal interosseous muscle. 1200 pulses will be given at a frequency of 1 Hz with an intensity of 90% of motor threshold in a total of 5 consecutive daily sessions, each lasting about 30 minutes. The washout period between the two treatments of the study will be 4 months, after which the participants will receive the alternate treatment. CONDITION: Cervical Dystonia PRIMARY OUTCOME: Improvement in Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) scores. Quality of life measures as measured by the The Short Form (36) Health Survey (SF‐36) SECONDARY OUTCOME: nil INCLUSION CRITERIA: Patients are to be recruited from the Botulinum Toxin Outpatient Clinics at the Monash Medical Centre. All consenting patients with clinical diagnosis of rotational cervical dystonia and stable requirements of Botulinum toxin in the previous 6 months will be included