Does the ability to stop ongoing movement differentiate cervical dystonia from functional cervical dystonia?

Area of Science:

• Neuroscience
• Movement Disorders
• Clinical Neurology

Background:

• Functional Cervical Dystonia (FCD) presents with hyperkinetic movements similar to Cervical Dystonia (CD).
• Previous research indicates impaired reactive inhibition in CD, evidenced by prolonged optimum combination Stop Signal Reaction Time (ocSSRT).

Purpose of the Study:

• To compare ocSSRT in patients with FCD, CD, and healthy individuals.
• To determine if ocSSRT can differentiate between FCD and CD.

Main Methods:

• Recruited 20 CD patients, 14 FCD patients, and 23 healthy controls.
• Utilized a portable device to measure median reaction time and ocSSRT during a button-release task with a stop-signal paradigm.

Main Results:

• CD patients exhibited significantly prolonged ocSSRT (373 ms) compared to FCD patients (285 ms) and healthy controls (248 ms).
• No significant difference in ocSSRT was observed between FCD patients and healthy controls.
• The ROC curve analysis showed ocSSRT could distinguish CD from FCD with an AUC of 0.775 (p=0.002).

Conclusions:

• ocSSRT is significantly impaired in CD but not in FCD.
• ocSSRT may serve as a valuable clinical biomarker for differentiating CD from FCD.