This 23-year-old woman reported the onset of left thumb “twitches” at the age of 16 years. The movements were present at rest and during posture holding, most noticeable in the left hand. She also noted “twitching” of the thighs. These movements had progressed over the last 2 years, worsening toward the end of the day. Handwriting was associated with
cramping of the right thumb. She was diagnosed with lupus at the age of 21 years. Besides the movements appreciated on the video, the rest of the neurological examination was normal.

These movements were at different times considered to represent tremor, myoclonus, or dystonia. In reality, they were too slow for myoclonus, too fast for dystonia, and too dysrhythmic for tremor. The jerks were asynchronous, showed variable amplitude but barely moved the joints, were not influenced by positional changes, and had similar magnitude at rest and on posture. Hence, the movements did not fit the bill for any of the hyperkinetic movement phenotypes known to occur from central nervous system pathology (myoclonus, dystonia, and tics).