4 mA tDCS improves walking ability in PSP: A case study
Durjoy Lahiri1, Carlos Roncero2, Alice Zhang2, Howard Chertkow1
1Neurology, 2Neuromodulation, Baycrest Health Sciences/Rotman Research
Objective:

The objective is to examine if tDCS can improve gait speed in people living with Progressive Supranuclear Palsy (PSP).

Background:

There is no current treatment for PSP. Neuromodulation with transcranial direct current stimulation (tDCS) works through modulating spontaneous activity of neural regions receiving electrical stimulation. The success of tDCS in individuals with motor-related diseases (Parkinson’s Disease and Stroke) indicates that it might be beneficial to individuals with PSP. Our lab (Chertkow-Roncero) has modeled electrical flow, finding that with two anode electrodes placed over the left and right deltoid muscles, and two cathode electrodes placed just ahead of the motor cortex on both sides (C3 & C4), electrical stimulation occurs in midbrain and subthalamic regions.  Using this PSP montage, a study from our lab has looked at the effects of tDCS on motor function in PSP, finding improvement persisting for a month.

Design/Methods:

An 84 year old lady with moderately severe PSP for 5 years and dependent on a walker, underwent two rounds of stimulation using the PSP montage, two months apart.  Each round consisted of twelve tDCS sessions over three weeks. In the first week of both rounds, sham tDCS was given to establish a pre-stimulation baseline, while one of two real tDCS montages was given in weeks two and three of each round. tDCS was given at an intensity of 4 mA. Primary outcome measure was gait time which is the time required to walk four lengths of the gait mat(24 meters).

Results:

Significant improvement in gait time compared to baseline (26.84% improvement immediately after second round and 18.82% at 2 weeks post-stimulation) was noted after the second round. In both the rounds, she demonstrated improvement in cadence, stride length and stride velocity.

Conclusions:

These results suggest tDCS can provide a significant improvement in the walking ability of people living with PSP.

10.1212/WNL.0000000000203396