Chapter 106 - Cervical Dystonia and Spasmodic Torticollis: Indications and Techniques

Abstract

Dystonia is the third most common movement disorder after Parkinson’s disease and essential tremor and is characterised by involuntary repetitive and/or twisting movements or abnormal postures from co-contraction of agonist and antagonist muscles. Cervical dystonia, of which spasmodic torticollis is the most common manifestation, is the most prevalent type of focal dystonia. In this chapter, we summarise the history and complex classification of dystonic conditions. We give an overview of the fundamental principles of medical management of dystonia. In particular, repeated botulinum toxin injections are effective in treating the majority of cases of cervical dystonia. Historically, several surgical strategies have been employed in medically-refractory cervical dystonia, which we briefly review. These include accessory nerve section, cervical rhizotomy and stereotactic brain lesions. However, the mainstay of current effective neurosurgical treatment revolves around deep brain stimulation of the globus pallidus pars interna for which there is a large body of experience and a strong evidence base, though other stimulation targets such as the subthalamic nucleus are showing promise as alternatives. We discuss details of pre-operative selection, surgical considerations and post-operative management when performing deep brain stimulation for cervical dystonia.