Changes in event-related potentials during dual task walking in aging and Parkinson's disease.

OBJECTIVE: To investigate EEG changes during an auditory odd-ball task while walking (dual-task) in young adults, older adults, and patients with Parkinson's disease. METHODS: 11 young adults, 10 older adults, and 10 patients with Parkinson's disease (PD) performed an auditory oddball task during standing and walking on a treadmill, while wearing a wireless EEG cap. The amplitude and latency of P300 were compared between groups and within conditions using linear mix model analysis. Gait was evaluated using wearable sensors and cognition was assessed using the Color Trail Test. RESULTS: P300 latency became longer during walking in all groups (p = 0.005). During walking, older adults (p = 0.005) and patients with PD (p = 0.001) showed prolonged P300 latency compared to young adults. Significant task by group interaction was found in P300 amplitude (p = 0.008). Patients with PD demonstrated reduced P300 amplitude during walking compared to standing (p = 0.023). Among all subjects, better motor and cognitive performance correlated with shorter P300 latency (r = 0.457, p = 0.014 and r = 0.431, p = 0.040, respectively). CONCLUSIONS: These findings provide direct evidence of the physiological recruitment of attentional networks during walking and their impact by ageing and disease. SIGNIFICANCE: This study is the first to report on changes in P300 latency and amplitude during dual-task oddball walking in older adults and patients with PD.

A motor learning-based intervention to ameliorate freezing of gait in subjects with Parkinson's disease.

Freezing of gait (FOG) is an episodic gait disturbance that is commonly seen in Parkinson's disease (PD). To date, treatment efficacy is limited. We tested the hypothesis that an intervention that utilizes motor learning provided through intensive cueing can alleviate this symptom. Fifteen subjects with PD suffering from FOG participated in a 6 week progressive motor learning program (three training sessions per week--open trial). A training session included FOG-provoking situations (e.g., turns). Prior to each presumed FOG provocation (e.g., just before a turn), rhythmic auditory stimulation (RAS) was elicited and the subject was trained to walk rhythmically, coordinate left-right stepping and to increase step size, utilizing the RAS cueing. Net training duration increased from week to week and secondary cognitive tasks while walking were added to increase FOG propensity. FOG symptom burden was assessed before, immediately, and 4 weeks after the training period. The mean number of FOG episodes (±SEM) per 10 m of walking in a standardized gait assessment decreased from 0.52 ± 0.29 in the pre-testing to 0.15 ± 0.04 in the post-testing (p < 0.05). The duration of FOG episodes decreased from 4.3 ± 2.1 to 2.6 ± 0.6 s (p < 0.05). Additional measures (e.g., FOG questionnaire, gait speed) varied in their responsiveness to the treatment. These effects were retained 4 weeks after the training. The results of this open label study support the possibility that a motor learning-based intervention is apparently effective in reducing FOG burden, suggesting that RAS can deliver 'anti-FOG' training.