Bradykinesia in Huntington's disease

Huntington's disease (HD) is characterized by the presence of hyperkinesias , but bra-dykinesia is also present in most patients. Wr studied the motor performance of is patients with genetically proven HD (age, 38.5 +/- 10 y; clinical stage, 1.7 +/- 1.7; (CAG) tripler length, 49.2 +/- 6.8 triplets; a ll but three patients were free from neuroleptics) and compared with a cont rol group (n = 18) and with a typical Parkinson's disease (PD) group (n = 2 0). Motor study included the four rimed tests commonly used for PD : Pronat ion-supination (PS), finger dexterity (FD), movement between two points (MT P) and walking test (WT). Tests were done at 9 AM. The PD group was studied in "off" condition, with no medication given for 12 hours. The HD group wa s slower than the controls on all tasks ( all tests significant, p < 0.01, Mann-Whitney U test) and even slower than PD group (for FD, p < 0.05). A si gnificant correlation was found between each rest and clinical stage (for P S, r = 0.84; for FD, r = 0.75; for MTP, r = 087, and for WT, r = 0.77, Pear son). Severe bradykinesia was present in HD, and motor impairment is relate d to clinical stage.