Neural correlates of visuospatial processing in migraine: does the pain network help?

Migraine patients frequently report cognitive symptoms during the different phases of migraine. The most affected cognitive domains are visuospatial abilities, processing speed, attention and executive functions. We explored migraine patients' performance during a visuospatial task and investigated the activity of brain areas involved in visuospatial processing. A functional magnetic resonance imaging (MRI) visuospatial task, including an angle and a colour discrimination paradigm, was administrated to 17 headache-free migraine patients and 16 controls. Correlations between functional MRI abnormalities and subjects' performance, clinical and neuropsychological variables were also investigated. Deficits at visuospatial cognitive tests were present in around 20% of patients. Migraine patients maintained a preserved behavioural performance (reaction time and number of correct responses) during the angle discrimination task, while they performed less correctly in the colour task compared to controls (p = 0.05).The comparison of angle vs. colour task revealed an increased activity of the right insula, bilateral orbitofrontal cortex and medial frontal gyrus, and decreased activity of the bilateral posterior cingulate cortex in migraine patients compared to controls. In migraine patients, a better performance in the angle task was associated with higher activation of the right insula and orbitofrontal cortex, as well as with decreased activation of the right posterior cingulate cortex. Our results suggest an adaptive functional plasticity that might help migraine patients to overcome impaired visuospatial skills and preserve an adequate performance during a visuospatial task. These compensatory mechanisms seem to take advantage of recruiting brain areas that are commonly involved also in nociception.