Involuntary Thumb Flexion on Neurological Examination: An Unusual Form of Upper Limb Dystonia in the Faroe Islands ...

• Main Authors: Kim, Christine Y., Petersen, Maria Skaalum, Eliasen, Eina H., Defazio, Giovanni, Greene, Paul, Jinnah, Hyder A., Tijssen, Marina A. J., Louis, Elan D.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Columbia University 2019
• Subjects: Dystonia; Thumb; Fingers > Abnormalities; Phenomenology > Research; Neurology; Faroe Islands
• Online Access: https://dx.doi.org/10.7916/d8-7kmn-fe68; https://academiccommons.columbia.edu/doi/10.7916/d8-7kmn-fe68

Background: The prevalence of dystonia varies worldwide. A prior report suggested a high prevalence of focal dystonia in the Faroese population, possibly reflecting a founder effect. During standardized neurological examination as part of an ongoing neuroepidemiologic study in the Faroe Islands, we noted an unusual phenomenon of thumb flexion during repetitive hand movements in a subset of subjects and sought to define its phenomenology. Methods: We requested commentary from a panel of dystonia experts regarding the phenomenology of the movements. These experts reviewed the videotaped neurological examination. Results: Among the experts, dystonia was the leading diagnosis. Alternate causes were considered, but deemed less likely. Discussion: Diagnosis of dystonia requires careful clinical assessment and consideration of associated features. We report a novel form of dystonia, not previously described to our knowledge, in this isolated population. Further studies of dystonia prevalence in the Faroe Islands ...