Article

Recovery of function after early brain injury depends upon both
reparative and compensatory processes that are minimally understood. Using
functional magnetic resonance imaging (fMRI), this study investigated the
reorganization of hemispheric brain activity of a 24 year old male who suffered
right prefrontal cortex damage at 7 years of age related to ruptured
arteriovenous malformation. His pattern of recovery has been examined and tracked
over the past 17 years and evolved from initial significant impairments in
executive, spatial and attentional abilities from the brain lesion to remarkable
recovery of function. METHODS: High field fMRI studies were completed with
experimental cognitive tasks sensitive to right prefrontal functions, including
visuospatial relational reasoning, spatial working memory, go no-go, emotional
face recognition, and coin calculation. Results were compared to a matched
control group for total hemispheric activity patterns. Results: Analyses revealed
that on fMRI activation tasks where the patient scored similar to controls, he
activated a broader network of bilateral cortical regions than controls. On tasks
where he scored lower than controls, there was under-activation of prefrontal
cortical regions in comparison to controls. CONCLUSION: Recovery of function
after prefrontal cortex damage in childhood can occur and be associated with
significant functional reorganization of hemispheric activity patterns (i.e.
developmental cerebral plasticity). Although not all tasks showed recovery to the
same extent in this case, those tasks with the most robust recovery entailed
compensatory activation of additional cortical regions on fMRI. Further studies
are needed to confirm and extend these findings.

Langue : ANGLAIS