Atypical Functional Brain Activation Seen in Leukoaraiosis
(HealthDay News) – Leukoaraiosis correlates with atypical functional activation during semantic decision tasks.
Kirk M. Welker, MD, from the Mayo Clinic in Rochester, MN, and colleagues examined the hypothesis that leukoaraiosis alters functional activation during a semantic decision language task using functional magnetic resonance imaging (MRI) of 18 right-handed, cognitively healthy elderly participants with an aggregate leukoaraiosis lesion volume of ≥25cm³ and 18 age-matched control participants with ≤5cm³ of leukoaraiosis.
The researchers found that semantic decisions activated the bilateral visual cortex, left posteroinferior temporal lobe, left posterior cingulate gyrus, left frontal lobe expressive language regions, and left basal ganglia in control participants. The right parietal and posterior temporal lobes were activated by visual perceptual decisions. There was reduced activation seen in all regions linked with semantic decisions in participants with leukoaraiosis; however, there was an increase in the extent of activation associated with visual perceptual decisions. In participants with leukoaraiosis, there were significant activation decreases in the left anterior occipital lobe, right posterior temporal lobe, and right basal ganglia. In addition, a strong trend (P=0.059) was seen toward greater left lateralization in the leukoaraiosis group in individual participant laterality indexes.
"In conclusion, leukoaraiosis is associated with abnormal functional MR imaging activation in elderly participants who are performing semantic decisions, and consequently, represents a potential confounding factor in other functional MR imaging studies of language," the authors write.
One author disclosed financial ties to the pharmaceutical industry.