Analysis Of The Characteristics Of Mismatch Negativity And Magnetic Resonance Images In Patients With Presbycusis

Objective In this study,mismatch negativity(MMN)test and magnetic resonance imaging(MRI)were used to explore the characteristics of neurophysiological sensitivity and structural changes of auditory cortex in patients with presbycusis(PC),and to further explore the correlation between the function and structure of auditory cortex and speech recognition in PC.Methods The case group(PC)consisted of 30 patients with presbycusis,aged from 61 to 85 years,including 17 males and 13 females.The elderly control group(HE)consisted of 11 healthy elderly people,aged 61-72 years,including 1 male and 10 females.The young control group(HY)consisted of 33 healthy young adults,aged 20-29 years,including 14 males and 19 females.All subjects underwent subjective auditory function test,objective auditory function test and brain MRI.The differences in MMN test Settings were 3k Hz,1k Hz and 500 Hz,respectively,mainly to obtain latency and amplitude.The cortical thickness(CT),surface area(CSA)and volume(CV)of bilateral region of interest(ROI)were obtained by Freesurfer.The main analysis was the intra-group differences of MMN and ROI indicators of three frequency differences of PC group and the inter-group differences with the control group,and the correlation between the two indexes of PC and phonetically balanced maximum(PBmax)was analyzed.Results ①The latency of 3k Hz difference in PC group was longer than that in HY group(P<0.05),and there was no difference between PC group and HE group.There was no statistically significant difference between the latencies of the three frequency differences.The amplitude of 3k Hz and 1k Hz difference was larger than that of HY group(P<0.001),and was not different from that of HE group.There was a significant difference among the amplitudes of three different frequencies(P<0.001),that is,the amplitude of MMN in PC group decreased with the decrease of frequency difference.②The CT of left Heschl’s Gyrus,right Heschl’s Sulcus,bilateral Planum Polare,bilateral Planum Temporale and bilateral Supratemporal Sulcus in PC group were smaller than those in HY group(P<0.05),and were similar to those in HE group.There were bilateral statistical differences in the Planum Polare and left lateralization.The CSA of bilateral Supratemporal Sulcus and right Planum Temporale in the HY group was smaller than that in the HE group(P<0.05),but similar to that in the HE group.The CSA of Heschl’s Gyrus,Heschl’s Sulcus,Planum Temporale and Heschl’s Sulcus showed significant left lateralization,while the Planum Polare showed right lateralization.The CV of bilateral Supratemporal Sulcus and right Planum Temporale in the HY group was lower than that in the HE group(P<0.05),but was similar to that in the HE group.The CV of the Heschl’s Gyrus,Supratemporal Sulcus,Planum Temporale and Heschl’s Sulcus showed significant left lateralization,while the Planum Polare showed right lateralization,which was consistent with the CSA lateralization.③In PC group,the latency of 500 Hz MMN was negatively correlated with the CSA and CV of the left Supratemporal Sulcus,while the amplitude of 500 Hz MMN was positively correlated with the CV of the left Planum Polare.In quiet environment,PBmax is positively correlated with the MMN amplitude of 3k Hz difference.CT of left Heschl’s Gyrus and left Planum Temporale were positively correlated with PBmax in quiet environment,CV of right Supratemporal Gyrus was positively correlated with PBmax in quiet environment,CT of right Heschl’s Gyrus and CSA of Planum Temporale were positively correlated with PBmax in noise environment.Conclusion The latency of MMN is partly prolonged,the amplitude is increased,and the bilateral auditory related brain areas are atrophied,especially the Supratemporal Sulcus.Aging may be the main influencing factor.The brain regions related to hearing loss in elderly patients are mainly left lateralization,and the Planum Polare and Supratemporal Sulcus may be right-skewed due to age and deafness.There is a partial correlation between speech recognition function and MMN and the structure of auditory related brain areas in presbycusis.