Leg stereotypy syndrome (LSS) is a common condition, occurring in up to 7% of otherwise healthy individuals, and it is even more common in patients with hyperkinetic movement disorders, a recent study found. Although it phenomenologically may overlap with other stereotypic disorders, researchers argue that it is a distinct, familial, neurological syndrome. They sought to characterize LSS in 2 groups of subjects: (1) general population (GP) group, defined as individuals accompanying patients but who are not genetically related to the patients; and (2) movement disorders (MD) group, composed of consecutive patients with diagnoses of restless legs syndrome, Parkinson disease, Tourette syndrome, and tardive dyskinesia. There were 92 participants enrolled in this study; 7% of 57 individuals in the GP group and 17% of those in the MD group met the diagnostic criteria for LSS. They found:

• In half of the individuals, the “shaking” involved predominantly 1 leg.
• All had a positive family history of similar disorder and none had diurnal variation.
• The 7-item Leg Stereotypy Syndrome Questionnaire was developed as a screening tool to aid in differentiating LSS from other movement disorders.