Very Early Brain Damage Leads to Remodeling of the Working Memory System in Adulthood: A Combined fMRI/Tractography Study.
The human brain can adapt to overcome injury even years after an initial insult. One hypothesis states that early brain injury survivors, by taking advantage of critical periods of high plasticity during childhood, should recover more successfully than those who suffer injury later in life. This hypothesis has been challenged by recent studies showing worse cognitive outcome in individuals with early brain injury, compared with individuals with later brain injury, with working memory particularly affected. We invited individuals who suffered perinatal brain injury (PBI) for an fMRI/diffusion MRI tractography study of working memory and hypothesized that, 30 years after the initial injury, working memory deficits in the PBI group would remain, despite compensatory activation in areas outside the typical working memory network. Furthermore we hypothesized that the amount of functional reorganization would be related to the level of injury to the dorsal cingulum tract, which connects medial frontal and parietal working memory structures. We found that adults who suffered PBI did not significantly differ from controls in working memory performance. They exhibited less activation in classic frontoparietal working memory areas and a relative overactivation of bilateral perisylvian cortex compared with controls. Structurally, the dorsal cingulum volume and hindrance-modulated orientational anisotropy was significantly reduced in the PBI group. Furthermore there was uniquely in the PBI group a significant negative correlation between the volume of this tract and activation in the bilateral perisylvian cortex and a positive correlation between this activation and task performance. This provides the first evidence of compensatory plasticity of the working memory network following PBI.
['Froudist-Walsh|Seán|S|', 'Karolis|Vyacheslav|V|', 'Caldinelli|Chiara|C|http://orcid.org/0000-0002-4703-0990', 'Brittain|Philip J|PJ|', 'Kroll|Jasmin|J|', 'Rodríguez-Toscano|Elisa|E|', 'Tesse|Marcello|M|', 'Colquhoun|Matthew|M|', 'Howes|Oliver|O|', "Dell'Acqua|Flavio|F|", 'Thiebaut de Schotten|Michel|M|', 'Murray|Robin M|RM|', 'Williams|Steven C R|SC|', 'Nosarti|Chiara|C|']
D000328:Adult D016880:Anisotropy D001921:Brain D001930:Brain Injuries D001931:Brain Mapping D056324:Diffusion Tensor Imaging D005260:Female D006801:Humans D007091:Image Processing, Computer-Assisted D062071:Infant, Extremely Premature D007361:Intelligence Tests D008279:Magnetic Resonance Imaging D008297:Male D008569:Memory Disorders D008570:Memory, Short-Term D009483:Neuropsychological Tests D010100:Oxygen D011930:Reaction Time D012737:Sex Factors
working memory fMRI tractography plasticity perinatal brain injury spherical deconvolution