Changes Of Brain Structures In Congenital Amusia Based On Surface-Based Morphometry Analysis

Background:Congenital amusia(CA)is a rare disorder characterized by deficits in pitch perception,and many structural and functional magnetic resonance imaging studies have been conducted to better understand its neural bases.However,a structural magnetic resonance imaging analysis using a surface-based morphology(SBM)method to identify regions with cortical features abnormalities at the vertex-based level has not yet been performed.Objective:To explore the cortical morphological changes in patients with CA by using a SBM method,and to explore the relationship between cortical morphological changes and music perception.In addition,we hope to find reliable neural markers of CA by receiver operator characteristic(ROC)analysis.Materials:We recruited students who sing out of tune and those with relatively normal musical ability from colleges in Hunan.The Montreal Battery of Evaluation of Amusia(MBEA)was used to differentiate CA from healthy controls(HC).According to the inclusion and exclusion criteria of the study,28 CA and 20 HC were eventually enrolled.A SBM method was used to identify cortical morphological abnormalities.Then,the surface parameters’ mean value of the identified clusters with statistically significant between-group differences were extracted and compared.Pearson’s correlation analysis was used to assess the correlation between the MBEA scores and surface parameters.Finally,ROC analysis was used to evaluate the diagnostic efficiency of each surface parameter.Results:1)Abnormal fractal dimension(FD)of right middle frontal gyrus,left pars triangularis,pars opercularis and left precentral gyrus were found in CA group.Abnormal sulcal depth(SD)was found in the right insula,superior temporal gyrus,pars triangularis and other brain areas in CA group.There were no statistically significant differences in gyrification index(GI)and cortical thickness(CT).2)Mean FD values of right middle frontal gyrus,left pars triangularis and pars opercularis,as well as mean SD values of right insula,superior temporal gyrus and pars triangularis were correlated with MBEA score,in which the right middle frontal gyrus was negatively correlated,while the rest were positively correlated.3)In ROC analysis,the mean FD value of right middle frontal gyrus,left pars opercularis,as well as the mean SD value of right insula and pars triangularis showed statistically significant differences in CA diagnosis.Conclusion:1)The cortical morphological changes in patients with CA exist in both cerebral hemispheres,but mainly in the right cerebral hemisphere.And some cortical morphological changes in patients with CA may be related to behavioral changes.2)Structural abnormalities in the bilateral frontal lobe and right insula may serve as neural markers of CA.3)Some brain regions,such as the bilateral frontal lobe,the right insula and temporal cortex,may be involved in the brain’s musical perception processing.