Background and aims Several studies have described poorer cognitive performance in various aspects of language such as comprehension, naming, expressive language and verbal fluency in individuals who were born very preterm compared to controls. Neuroimaging investigations have also described structural and functional changes that could underlie such language deficits. In this pilot study we used functional MRI to explore whether alterations in the neuroanatomy of phonological verbal fluency persisted into adulthood following very preterm birth.
Methods Twenty-two young adults (26–28 years old, females=11, males=11) were examined. Eleven individuals were born very preterm (gestational age: < 33 weeks) and 11 were full-term born controls. All participants underwent functional MRI using a 3T scanner while completing a phonological verbal fluency task. All data pre- and post-processing was performed using FSL (www.fmrib.ox.ac.uk/fsl).
Results During successful verbal fluency trials, very preterm- born individuals showed significantly decreased blood-oxygen- level-dependent signal compared to controls in several brain areas including the orbitofrontal/medial frontal cortex bilaterally (x=8mm, y=52mm, z= –28mm) and the left fusiform/parahippocampal gyrus (x= –34mm, y= –30mm, z= –24mm), p<0.05 family wise-error corrected (FWE). On-line performance did not significantly differ between the groups.
Conclusions Previous studies with functional MRI in younger samples have shown neuroanatomical alterations (increased and decreased activation) in fronto-temporal and fronto-striatal networks in very preterm born individuals when performing different cognitive tasks. Our results suggest that neuroanatomical alterations during language processing persist into adult life following very pre-term birth, and specifically involve fronto-temporal networks, with important implications for a wide range of high order cognitive functions.