Applicability and Tolerability of Electrical Stimulation Applied to the Skin Surface of the Upper and Lower Leg for Cueing Applications in Parkinson's Disease

Abstract Due to possible sensory impairments in people with Parkinson\u0027s disease, several methodological aspects of electrical stimulation as a potential cueing method remain to be explored. This study aimed to investigate the applicability and tolerability of sensory and motor electrical stimulation in 10 people with Parkinson\u0027s disease. The study focused on assessing the electrical stimulation voltages and visual analogue scale discomfort scores at the electrical sensory, motor, discomfort, and pain thresholds. Results show that sensory electrical stimulation at the tibialis anterior, soleus, hamstrings, and quadriceps stimulation sites was applicable and tolerable for 6/10, 10/10, 9/10, and 10/10 participants, respectively. Furthermore, motor electrical stimulation at the tibialis anterior, soleus, hamstrings, and quadriceps stimulation sites were applicable and tolerable for 7/10, 7/10, 7/10, and 8/10 participants, respectively. Interestingly, the thresholds associated with the lower leg corresponded to higher electrical stimulation intensities compared to the thresholds associated with the upper leg. The data presented in this paper indicate that sensory and motor electrical stimulation is applicable and tolerable for cueing applications in people with Parkinson\u0027s disease. Sensory electrical stimulation was applicable and tolerable at the soleus and quadriceps sites. Motor electrical stimulation was not tolerable for two participants at any of the proposed stimulation sites. Therefore, future studies investigating motor electrical stimulation cueing should apply with caution in people with Parkinson\u0027s disease.