The Effect of Computed Tomography-Guided Botulinum Toxin Injection on Cervical Dystonia, Confirmed by a 9-Month Follow-Up Using Positron Emission Tomography/Computed Tomography.

Although accurate targeting of the causative muscles is of paramount importance in the treatment of focal dystonia, this is often challenging because of distortion of the affected anatomical structures and difficulty in proper positioning of injections. We report a case of idiopathic cervical dystonia that was treated by computed tomography-guided injection of botulinum toxin into multiple deep muscles. Based on clinical presentation of combined torticollis and retrocollis, and needle electromyography results, botulinum toxin was injected under electromyography guidance. This treatment resulted in no improvement. Subsequently, target muscles were identified using F-fludeoxyglucose fusion positron emission tomography/computed tomography. botulinum toxin was injected into the hypermetabolic muscles guided by computed tomography. This injection successfully relieved the symptoms, and nine months of follow-up using positron emission tomography/computed tomography confirmed that hypermetabolic muscles had been normalized. This case indicated that computed tomography guidance may facilitate accurate targeting of botulinum toxin injection. To the authors' knowledge, this is the first case reporting a positive effect of botulinum toxin on cervical dystonia symptoms that lasted 9 mos, confirmed by follow-up positron emission tomography/computed tomography.