[P2.042] Tricks to Treatments: Sensory Tricks in Dystonia

Vesper Ramos, Barbara Karp, Mark Hallett
Bethesda, MD, USA


OBJECTIVE:
To enumerate the various forms of sensory tricks(ST) according to dystonia type, and describe the prevalence, effectiveness, and relationship of ST to deep brain stimulation and botulinum toxin injection.
BACKGROUND:
Sensory tricks(ST) are specific maneuvers that temporarily ameliorate dystonia in a manner that is not easily physiologically explainable. Ambiguity and variety is remarkable but common characteristics are well known anecdotally.
DESIGN/METHODS:
We reviewed the literature pertaining to ST, including variants like forcible tricks (FT), reverse sensory tricks (rST), imaginary tricks(IT), and motor tricks (MT).
RESULTS:
We enumerated and organized described ST and adaptive devices in literature. There is a wide range of reported prevalence numbers for ST in dystonia. Effect duration is also variable. About 10% of ST lose effectiveness over time. Conflicting studies raise an issue of how to judge the effectiveness of ST. It may be by change in the dystonic position, using various clinical scales, decrease in dystonic EMG activity or the patient's subjective report of relief. We highlighted neurophysiologic evidence for ST decreasing abnormal dystonic facilitation and postulate a multi-step gating, processing, and adaptive model. Successful treatments have been developed by mimicking patients' known ST, albeit rare. Deep brain stimulation and botulinum toxin appear to interact with the effectiveness of ST, but the mechanisms are unknown.
CONCLUSIONS:
We propose a new classification of ST,to include its variants, such as FT, MT, IT and rST. Wide range of prevalence and effectiveness of ST may reflect ambiguity of terminology and varying measures. More studies are needed to determine the interaction of deep brain stimulation and botulinum toxin with ST. Our research points to more benefit than harm for searching for, or even inducing, ST in patients with dystonia.
Study Supported by:
National Institutes of Health and the National Institute of Neurological Disorders and Stroke, and the the Dystonia Medical Research Foundation.
Category - Movement Disorders: Dystonia

Tuesday, April 29, 2014 7:30 AM

P2: Poster Session II: Movement Disorders: Dystonia (7:30 AM-11:00 AM)

 

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