Investigators at Universities of Naples and Salerno, Italy; and Maastricht University, the Netherlands, explored the functional response of vestibular neural pathways using whole-brain blood oxygen level dependent (BOLD) fMRI during caloric vestibular stimulation in 12 patients (mean age 31.2 +/- 5 yrs) with vestibular migraine (VM), in 12 healthy controls, and in a group of age- and sex-matched patients with migraine without aura (MwoA). In all subjects, caloric vestibular stimulation elicited activation in bilateral insular cortex (right > left), right parietal cortex, right thalamus, brainstem, and cerebellum. While all participants demonstrated this general pattern of response, patients with VM showed a significantly increased left medio-dorsal thalamic activation in response to an ipsilateral vestibular stimulation, relative to both healthy controls and patients with MwoA. The magnitude of the thalamic activation was positively correlated with the frequency of migraine attacks in patients with VM. 
COMMENTARY. Patients with VM have abnormal thalamic functional response to vestibular stimulation. These findings are consistent with the current view of VM as a migraine subtype clinically characterized by vestibular symptoms and correlated with interictal dysfunctional central vestibulo-thalamocortical processing . Both structural and functional thalamic abnormalities are documented in patients with migraine .