Immediate effects of rhythmic auditory stimulation on gait kinematics in Parkinson's disease ON/OFF medication.

• Rhythmic Auditory Stimulation (RAS) instantly improves parkinsonian gait, regardless of the dopaminergic drug. • A frequency of 110% of the preferred walking cadence is the most effective stimulus. • RAS improves spatio-temporal parameters and gait phases distribution, but leaves joint kinematics unaltered. Gait impairment is a highly disabling symptom for Parkinson's disease (PD) patients. Rhythmic auditory stimulation (RAS), has shown to improve spatio-temporal gait parameters in PD, but only a few studies have focused on their effects on gait kinematics, and the ideal stimulation frequency has still not been identified. We enrolled 30 PD patients and 18 controls. Patients were evaluated under two conditions (with (ON), and without (OFF) medications) with three different RAS frequencies (90%, 100%, and 110% of the patient's preferred walking cadence). Spatial-temporal parameters, joint angles and gait phases distribution were evaluated. A novel global index (GPQI) was used to quantify the difference in gait phase distribution. Along with benefits in spatial-temporal parameters, GPQI improved significantly with RAS at a frequency of 110% for both ON and OFF medication conditions. In the most severe patients, the same result was observed also with RAS at 100%. RAS administration, at a frequency of 110% of the preferred walking frequency, can be beneficial in improving the gait pattern in PD patients. When rhythmic auditory stimulation is provided to patients with PD, the selection of an adequate frequency of stimulation can optimize their effects on gait pattern. [ABSTRACT FROM AUTHOR]