Evaluation of ActiTrac (ambulatory activity monitor) in Parkinson's Disease

At present, the evaluation of Parkinson's Disease (PD) relies mainly on Unified Parkinson's Disease Rating Scale (UPDRS). Other objective measures have been proposed, including functional studies, timed tests and ambulatory activity monitors (AAM). We carried out a prospective study to analyze the utility and correlation of the AAM: ActiTrac with UPDRS scores and timed tests in patients with PD. We studied 28 patients with idiopathic PD (age: 62 +/- 11 years; duration of illness: 7.7 +/- 4.4 years; clinical stage 2.3 +/- 0.39). Motor evaluation included UPDRS and five timed tests: Purdue Pegboard test and those proposed in CAPIT protocol, pronation-supination (PS), finger dexterity (FD), movement between two points (MTP) and walking test (WT). Clinical evaluation was performed in off condition, at 9 a.m., (12h off their medication). Finally, ActiTrac was placed on the wrist (more affected side) continuously for at least 72h. ActiTrac activity was correlated (Spearman) with total UPDRS (r: - 0.53, p < 0.005) and motor UPDRS (r:- 0.46, p: 0.01); UPDRS rigidity subscore (r:- 0.52, p < 0.01); UPDRS bradykinesia subscore (r:- 0.48; p:0.01); FD (r: - 0.47 p: 0.01), WT (r: - 0.49, p < 0.01) and Purdue test (r:0.54; p < 0.01). ActiTrac seems to be a reasonably accurate method to evaluate motor activity in PD.