Tizanidine in cranial dystonia.

Area of Science:

• Neuroscience
• Clinical Pharmacology

Background:

• Electrophysiological studies suggest brainstem interneuron hyperactivity in cranial dystonia (CD).
• Tizanidine (Tz), a muscle relaxant, antagonizes excitatory interneurons, theoretically benefiting CD.

Purpose of the Study:

• To evaluate the efficacy of tizanidine in patients with cranial dystonia.

Main Methods:

• An open-label, single-blind placebo wash-in study.
• Ten patients with CD were enrolled.
• Doses ranged from 28-36 mg/day.

Main Results:

• Tizanidine was largely ineffective in alleviating CD symptoms.
• Eight patients tolerated the medication.

Conclusions:

• The ineffectiveness of Tz suggests brainstem interneuron hyperactivity may not be the primary driver of CD.
• Further studies with electrophysiological assessments are needed.
• CD symptoms might stem from other basal ganglia disease mechanisms.