Writer’s cramp (WC) is a form of task-specific focal dystonia which causes excessive contractions of the muscles of the forearm and hand activated by writing. Other motor tasks of the hand may become affected over time, at which point it is referred to as dystonic writer’s cramp. WC is a subtype of other occupational cramp disorders, the best known of which is musician’s cramp occurring in pianists or string players. WC was originally described in individuals whose occupation demanded unusually large amounts of writing but may also occur in the absence of excessive writing. Forearm pain and a variety of abnormal postures of the hand and fingers are observed within moments of beginning to write such as excessive flexion of the fingers or thumb, excessive wrist flexion, or hyperextension of one or more digits.
KeywordsBotulinum Toxin Motor Task Botulinum Toxin Injection Abnormal Posture Focal Dystonia
Writer’s Cramp.mp4 (MP4 5,819KB)
The patient exhibits involuntary extension at the metacarpophalangeal joint of the index finger while writing.