Subjects must have a prior diagnosis of cervical dystonia and be capable of participating in all study procedures. Subjects will undergo assessment of non-motor features.

Subjects must be a first order relation of a Vanderbilt patient diagnosed with cervical dystonia. The subject must pass a short neurological examination to ensure the subject does not have cervical dystonia or any sensory deficits. Subjects will undergo assessment of non-motor features.

Subjects must be healthy volunteers who are neurologically normal. The subject must pass a short neurological examination to ensure the subject does not have cervical dystonia or any sensory deficits. Subjects will undergo assessment of non-motor features.

The family members and healthy volunteers will undergo elements of the neurological examination during which the movement disorders neurologist will look specifically for the presence of cervical dystonia and other sensory abnormalities. If the subject is found to have cervical dystonia or any other sensory abnormalities, the subject will be excluded from the study.

For participants in all groups, the investigators will examine the prevalence of spatial discrimination threshold. Prevalence of spatial discrimination threshold will be determined with a task using Johnson-Van-Boven-Phillips (JVP) domes. The spatial discrimination threshold will be recorded as the mean of both hands at the 75% level of accuracy. The research coordinator will report prevalence of spatial discrimination threshold as a descriptive statistic.

For participants in all groups, the investigators will examine the prevalence of temporal discrimination threshold. Prevalence of temporal discrimination threshold will be determined with a visual-visual discrimination task.The research coordinator will report prevalence of temporal discrimination threshold as a descriptive statistic.

For participants in all groups, the investigators will examine the prevalence of vibration-induced illusion of movement. Prevalence of vibration-induced illusion of movement will be determined by recording the change in displacement of the tracking arm during a vibration-induced illusion of movement task. The research coordinator will report prevalence of vibration-induced illusion of movement as a descriptive statistic.

For participants in all groups, the investigators will examine the prevalence of impaired kinesthesia. Kinesthesia will be determined by a neurologist during the neurological examination. The research coordinator will report prevalence of impaired kinesthesia as a descriptive statistic.

The concurrence of multiple non-motor symptoms will be assessed using a multinomial logistic regression model to determine if a distinct combination of non-motor symptoms is more prevalent in the cervical dystonia patient group than in the unaffected family members or healthy volunteer groups.

Analysis of demographic factors will be performed to identify additional environmental factors that are more prevalent in the CD patient population than in healthy controls and unaffected family members. Through exploration of potential new indicators, the investigators hope to progress the long-term goal of improving the rate of cervical dystonia diagnosis.