Long Term Improvement of Episodic Memory in Stroke Patients Following a Short Treatment with Prism Adaptation and Serious Games

Abstract

Episodic memory deficits are frequently encountered following stroke. Rehabilitation of these deficits is often associated with short term effects that do not persist at follow up times. Neuromodulation tools acting on alterations of excitation/inhibition dynamics could be useful for rehabilitation of episodic memory. Prism adaptation with visual field deviation ipsilateral to the affected hemisphere can specifically modulate brain excitability and lead to improvement of cognitive deficits in post-stroke patients. Here we investigated whether prism adaptation followed by digital cognitive training could induce long term improvement of episodic memory deficits in stroke patients as compared with traditional rehabilitation.

Sixty stroke patients were recruited for the study. Thirty patients were treated with prism adaptation combined with serious games targeting executive processes, with a ten days protocol (experimental group); thirty patients were treated with conventional rehabilitation (control group). Patients were tested with a battery of neuropsychological tests, including verbal and visual episodic memory tasks at four times: at baseline (T0); immediately after the end of the rehab protocol (T1); after 3 months (T2); after six months (T3).

The main results showed a significant long term effect of the experimental treatment on both immediate and delayed recall phases of the visual episodic memory task. The effects were not linked to the affected hemisphere (right vs. left), nor to the hemorrhagic or ischemic type of stroke nor to the cortical or subcortical site of lesion.

These findings show for the first time an improvement of long term memory in stroke patients following the use of a medical device combining prism adaptation and digital cognitive training, paving the way to novel rehabilitation techniques for cognitive deficits in stroke.