Rehabilitation of Unilateral Spatial Neglect: A Combined Behavioral and fMRI Single-Case Study

Objective: Symptoms of visuospatial neglect occur frequently after unilateral brain damage. Neglect hampers general rehabilitation progress and is associated with reduced quality of life. Some of the rehabilitation programs developed to treat neglect have demonstrated behavioral improvements. However, only a few of them have addressed specifically the anatomo-functional correlates associated behavioral improvement. Method: Here we describe the case of a patient (GV) with a severe left neglect disorder as a consequence of a right hemisphere stroke. Eighteen weeks after the onset, he underwent a 10-week intensive neuropsychological rehabilitation program. Functional MRI (fMRI) during execution of a covert attention task, and a broad neuropsychological assessment were conducted before and after the training. Results: The results show a significant improvement of the performance in neglect tasks after the rehabilitation program, although the remission of symptoms was not complete. fMRI data showed that the behavioral improvement was accompanied by an increase of activity in the dorsal premotor cortex and middle frontal gyrus bilaterally. Other activations were present only in the contralesional left hemisphere, including supplementary motor area and superior temporal gyrus. Conclusions: The implications of the results are discussed. General Scientific Summary This study suggests that the behavioral improvement observed after an intensive neuropsychological rehabilitation training, involves a neural reorganization of the right hemisphere, and specifically of the dorsal premotor cortex. Additionally, the study highlights the efficacy of this type of rehabilitation program in neglect patients.