Non-Motor Features of Cervical Dystonia (CD)

The primary aim of this study is to identify the prevalence of four previously identified
non-motor markers - (1) spatial discrimination threshold, (2) temporal discrimination
threshold, (3) vibration-induced illusion of movement, and (4) kinesthesia - in a population
of cervical dystonia patients, unaffected family members, and healthy volunteers (control
group). Consenting participants will receive a neurological examination performed by a
movement disorders neurologist, followed by an assessment of the four non-motor symptoms.

The investigators hypothesize that a distinct combination of non-motor symptoms will be more
prevalent in the CD group, and therefore this set of symptoms may be indicative of disease
development. This combination will be identified through analysis of the concurrence of the
non-motor features across the three groups of participants. This study will fill an important
unmet need, as to the investigators' knowledge there are no published studies assessing the
comorbid presentation of these four non-motor symptoms in a single cervical dystonia
population. The exploration of a distinct combination of concurrent non-motor symptoms as a
marker for the development of cervical dystonia will improve the ability of movement
disorders neurologists to diagnose the condition.

The results of this study will facilitate the investigators' longstanding aim of improving
rates of cervical dystonia diagnosis. Cervical dystonia is currently diagnosed based upon the
exclusion of other movement disorders; therefore, characterization of non-motor features in
cervical dystonia patients will help to refine the diagnostic criteria for this condition.
This investigation will also improve understanding of the factors associated with CD. Future
studies can examine the source of these associated factors in order to help understand the
cause of CD, since the etiology is currently unknown.

Inclusion Criteria:

- Have a diagnosis of cervical dystonia, OR a first order relation of a Vanderbilt
patient diagnosed with cervical dystonia, OR a healthy volunteer who is neurologically
normal

- Capable of participating in all study procedures

- Willing and able to provide written or verbal informed consent.

Exclusion Criteria:

- Subjects for whom participation in the study may cause medical harm

- Subjects who are not considered competent to make their own medical decisions

- Subjects who display sensory deficits during a short screening examination prior to
study enrollment