Childhood Hypertonia of Central Origin: A Trial of Anticholinergic Treatment Effects

Inclusion Criteria: Dystonia in the dominant upper extremity Exclusion Criteria: Complete absence of voluntary movement in the affected hands, wrists, and elbows Severe weakness in the dominant upper extremity (MRC grade < 4) Passive range of motion at the hand, wrist or elbow less than 80% of normal Current use of medications for dystonia (anticholinergics, L-dopa, baclofen, diazepam, tizanidine, tetrabenazine, reserpine, and others) Changes in the subject's physical therapy regimen for the duration of the 15-week study Prior use of trihexyphenidyl or other anticholinergic therapy for dystonia. History of surgery on the dominant upper extremity or cervical spine Botulinum toxin injection in the dominant upper extremity within the previous 6 months Current or prior implantation of an intrathecal baclofen pump, deep brain stimulator, or other device to treat dystonia or spasticity Concurrent acute or chronic medical condition (such as frequent seizures, heart disease, or asthma) that could adversely affect motor performance or the safety of testing Presence of diurnal fluctuations or other clinical signs and symptoms suggesting an inborn error of metabolism, a family history of dystonia suggesting a genetic dystonia, or dystonia due to injury after the neonatal period (including toxin exposure, trauma, or medication-induced) History of allergic or adverse reaction to trihexyphenidyl or other anticholinergic medications Current complaint of urinary retention requiring treatment. History of glaucoma, or family history of glaucoma with onset before age 40