Prevalence estimates and clinical characterization for tremor and dystonia in Progressive Supranuclear Palsy

Congratulations to Aparna Wagle-ShuklaAnand RajanZakia JabarkheelNikolaus McFarland on the publication of “Prevalence estimates and clinical characterization for tremor and dystonia in Progressive Supranuclear Palsy.”  This article was published in the April 9, edition of Neurology.



Objective: Determine the prevalence rate and clinical characteristics of tremor and dystonia in patients with progressive supranuclear palsy (PSP).

Background: Tremor and dystonia are known to occur in PSP and can sometimes present together. However, there is scant literature on the prevalence and the clinical characteristics of these features, which may help with diagnosis of PSP and development of better-targeted therapies.

Design/Methods: We conducted a retrospective analysis of 217 PSP patients. Diagnosis of PSP was established using recent criteria recommended by the Movement Disorders Society. Data for patients exhibiting tremor, dystonia or both were extracted. Demographics and disease-related characteristics were noted. Tremor and dystonia were both classified based on body distribution. Arm tremor was further classified based on severity and activation condition (rest/posture/action).

Results: 71 patients (33% of 217) with tremor were identified (35 males, 36 females; mean age 72.8 ± 8.2 years; mean disease duration 5.4 ± 4.2 years). Tremor distribution included 68 arm (58 mild, 10 moderate, none severe); 3 head; 6 leg; and 5 with tremor affecting multiple body parts. Arm tremor was noted as rest in 34; postural in 35 and action in 61 patients. 66 patients (30%) with dystonia were identified (28 males, 38 females, mean age 73.0 ± 7.6 years, mean disease duration 5.3 ± 4.3 years). Distribution of dystonia included 33 cervical, 17 blepharospasm, 43 limb, 4 cranial (face, jaw, tongue) and 5 generalized. Only 27 patients (12%) presented with combined tremor + dystonia, of which 16 had tremor and dystonia affecting the same body part (mainly limbs).

Conclusions: In a large PSP cohort, nearly a third of patients had tremor or dystonia, but these were infrequently co-occurring. Tremor was characteristically a mild, action tremor involving the arms. Dystonia was more prevalent in females and mainly focal, involving the limbs more than the axial or cervical region.