Anodal transcranial direct current stimulation over the left temporal pole restores normal visual evoked potential habituation in interictal migraineurs

Abstract

BackgroundNeuroimaging data has implicated the temporal pole (TP) in migraine pathophysiology; the density and functional activity of the TP were reported to fluctuate in accordance with the migraine cycle. Yet, the exact link between TP morpho-functional abnormalities and migraine is unknown. Here, we examined whether non-invasive anodal transcranial direct current stimulation (tDCS) ameliorates abnormal interictal multimodal sensory processing in patients with migraine.MethodsWe examined the habituation of visual evoked potentials and median nerve somatosensory evoked potentials (SSEP) before and immediately after 20-min anodal tDCS (2 mA) or sham stimulation delivered over the left TP in interictal migraineurs.ResultsPrior to tDCS, interictal migraineurs did not exhibit habituation in response to repetitive visual or somatosensory stimulation. After anodal tDCS but not sham stimulation, migraineurs exhibited normal habituation responses to visual stimulation; however, tDCS had no effect on SSEP habituation in migraineurs.ConclusionOur study shows for the first time that enhancing excitability of the TP with anodal tDCS normalizes abnormal interictal visual information processing in migraineurs. This finding has implications for the role of the TP in migraine, and specifically highlights the ventral stream of the visual pathway as a pathophysiological neural substrate for abnormal visual processing in migraine.

Cortical and subcortical changes following sphenopalatine ganglion blocks in chronic migraine with medication overuse headache: a preliminary longitudinal study

“…Results from numerous prior studies are consistent with a central role of the temporal lobe in the psychophysiology and cyclical recurrence of migraine [19,[60][61][62][63][64].…”

Brain Correlates of Single Trial Visual Evoked Potentials in Migraine: More Than Meets the Eye

“…If hyper-responsiveness in migraine were to be considered as resulting from of a network dysfunction rather than a primary local phenomenon, novel therapeutic opportunities may arise. Indeed, as shown in recent studies, dorsal fronto-parietal areas can causally modulate the activity of visual areas ( 35 ) and anodal transcranial direct current stimulation of the left temporal pole is able to normalize visual responses in migraine patients ( 50 ). Rather than targeting the primary visual cortex, which yielded equivocal results in therapeutic trials ( 48 ), non-invasive neurostimulation of other areas in the visual attention network could be more effective for the preventive treatment of migraine.…”

Evaluation of gray matter perfusion in episodic migraine using voxel-wise comparison of 3D pseudo-continuous arterial spin labeling

“…The TP was hyperexcitable with painful heat stimulation and showed increased resting-state connectivity with hypothalamic in interictal migraine patients, indicating that TP may be involved in the interictal hypersensitivity to pain, smell and light [ 40 , 41 ].In another fMRI study, increased average regional homogeneity values in TP showed significantly positive correlations with disease duration of MO [ 42 ]. During odour stimulation in a H(2)(15)O-PET study, migraineurs showed significantly higher activation than controls in the left TP, suggesting a role in olfactory hypersensitivity of migraine [ 43 ].A recent study found that enhancing excitability of the TP with non-invasive anodal transcranial direct current stimulation normalized abnormal interictal visual information processing in migraineurs [ 44 ], supporting TP as a possible therapeutic target to relieve hypersensitivity of migraine. Our study further provides evidence of TP perfusion abnormality in interictal migraine and this structure needs deeper investigation.…”