Dystonia is an acute, alarming involuntary movement disorder that can be painful and distressing, and erodes patient trust and compliance. 31 It is characterized by briefly sustained or intermittent spasms or contractions of antagonistic muscle groups resulting in twisting and repetitive movements or postures. Drug-induced dystonia can affect any muscle group, but most commonly involves the head, neck, jaw, eyes and mouth resulting in spasmodic torticollis, retro- or anterocollis, trismus and dental trauma, forced jaw-opening or dislocation, grimacing, blepharospasm, tongue biting, protrusion or twisting, and distortion of the lips.32-34 It is not action or sensory stimulus dependent. More subtle signs, including muscle cramps or tightness of the jaw and tongue with difficulty speaking or chewing, may precede dystonia or occur alone.
|