Headache is associated with aberrant cerebral blood flow in chronic tinnitus revealed by perfusion functional MRI

Background: Chronic tinnitus is often accompanied with headache symptom that will affect the cerebral blood flow (CBF) and exacerbate the tinnitus distress. However, the potential relationship between headache and tinnitus remains unclear. This study will investigate whether aberrant CBF patterns exist in chronic tinnitus patients and examine the influence of headache on CBF alterations in chronic tinnitus. Methods: Participants included chronic tinnitus patients (n=45) and non-tinnitus controls (n=50), matched for age, sex, education, and hearing thresholds. CBF images were collected and analyzed using arterial spin labeling (ASL) perfusion functional magnetic resonance imaging (fMRI). Regions with major CBF differences between tinnitus patients and non-tinnitus controls were first detected. The interaction effects between headache and tinnitus for CBF alterations were further examined. Correlation analyses illustrated the association between CBF values and tinnitus severity as well as between CBF and degree of headache.Results: Compared with non-tinnitus controls, chronic tinnitus patients exhibited decreased CBF, primarily in right superior temporal gyrus (STG), bilateral middle frontal gyrus (MFG), and left superior frontal gyrus (SFG); decreased CBF in these regions was correlated with tinnitus distress. There was a significant interaction effect between headache and tinnitus for CBF in right STG and MFG. Moreover, the degree of headache correlated negatively with CBF in tinnitus patients.Conclusions: Chronic tinnitus patients exhibited reduced CBF in the auditory and prefrontal cortex. Headache may facilitate a CBF decrease in the setting of tinnitus, which may underlie the neuropathological mechanisms of chronic tinnitus comorbid with headache.