Observing the Diversity of Alleviating Manoeuvres in Cervical Dystonia

Abstract

The alleviating manoeuvres (AMs), classically referred to as “sensory tricks” are voluntary manoeuvres that temporarily improve dystonic postures. Although self-induced application of sensory stimuli is the most common AM, clinical experience suggests that the phenomenon is more diverse, possibly reflecting the complexity of the pathophysiological mechanisms provoking dystonia. We specifically explored five different categories of AMs in patients with cervical dystonia (CD): 1) pure sensory; sensorimotor manoeuvres in which sensory input is associated with a motor output component incorporating 2) active non-oppositional, 3) active oppositional or 4) passive motion; and 5) complex motor manoeuvres. Using an ad hoc structured clinical interview, we collected data on the frequency and efficacy of each subgroup and the possible correlation with some clinical features of CD. One-hundred patients were included in this study. Seventy-five percent of patients reported at least one AM. Half of those reporting AMs acknowledged the use of different phenomenological categories of AMs. Different categories of AMs showed noteworthy differences in prevalence of use amongst CD patients, and in the relationship of frequency of use and efficacy to patient demographic and clinical characteristics. Our observational study supports the existence of different AMs that are phenomenologically different and could be related to different degrees of sensorimotor integration dysfunction. Given that AMs are probably the most efficacious, non-invasive strategy to ameliorate CD and other dystonias, accurate phenotyping and physiological exploration of their diversity may produce relevant insight for new therapeutic strategies or appraisal of existing ones.