Dysfunction of Inferior Parietal Lobule During Sensory Gating in Patients With Amnestic Mild Cognitive Impairment

Abstract

Patients with amnestic mild cognitive impairment (aMCI) demonstrate significant cognitive deficits, especially in the memory aspect. The memory deficiency might be attributed to the difficulties in the inhibitory function to suppress redundant stimuli. Sensory gating (SG) refers to the attenuation of neural responses to the second identical stimulus in a paired-click paradigm, in which auditory stimuli are delivered in pairs with inter-stimulus intervals (ISI) of 500 ms and inter-pair intervals of 6-8 s. It is considered as an electrophysiological signal to reflect the brain's automatic response to gate out repetitive sensory inputs. However, there has been no study systematically investigating SG function in aMCI patients. Thus, the present study used magnetoencephalography (MEG) to record neuromagnetic responses to a paired-click paradigm in 23 healthy controls (HC) and 26 aMCI patients. The Stimulus 2/Stimulus 1 (S2/S1) amplitude ratio was used to represent the SG function. Compared to HC, aMCI patients showed M50 SG deficits in the left inferior frontal gyrus (IFG) and right inferior parietal lobule (IPL). M100 SG defects were also observed in the right IPL. Based on the ROIs showing significant between-group SG differences, we found that a more deficient M50 SG function in the right IPL was associated with poorer performance in the immediate recall of Logic Memory (LM), Chinese Version Verbal Learning Test (CVVLT) and Digit Span Backward (DSB) Test. Furthermore, the M50 SG ratios of the right IPL together with the neuropsychological performance of LM and CVVLT demonstrated very good accuracy in the discrimination of aMCI from HC. In conclusion, compared to HC, aMCI patients showed a significant SG deficit in the right IPL, which was correlated with the auditory short-term memory function. We suggest the combination of SG in the right IPL, LM and CVVLT to be sensitive indicators to differentiate aMCI patients from HC.

An Activation Likelihood Estimation Meta-Analysis of Specific Functional Alterations in Dorsal Attention Network in Mild Cognitive Impairment

“…A study demonstrated that M50 sensory gating (SG) deficits in the IPL were related to the poorer performance in the immediate recall of logic memory (LM). Obviously, patients with MCI showed lower auditory short-term memory function with the deficit in the IPL in clinical manifestations ( Cheng et al, 2020 ). It can be concluded that decreased ReHo can be related to the clinical manifestations of patients with MCI.…”

Altered mismatch response of inferior parietal lobule in amnestic mild cognitive impairment: A magnetoencephalographic study

“… 34 LM: a brief story was spoken to the subject to measure immediate and delayed recall memory function. 35 DSB: a series of digits were spoken to the subject to measure the auditory working memory. 36 …”

“…LM: a brief story was spoken to the subject to measure immediate and delayed recall memory function. 35 …”

“…Based on that the MMNm reflects functional integrity of auditory sensory memory and the patients with aMCI exhibit impairments in memory function, we specifically examined the following auditory/verbal memory tests in relation to MMNm: CVVLT: Nine two‐character nouns were spoken to the subject to measure total (learning over 4 trials) and delayed recall scores 34 LM: a brief story was spoken to the subject to measure immediate and delayed recall memory function 35 DSB: a series of digits were spoken to the subject to measure the auditory working memory 36 …”

Neuromagnetic evidence of abnormal automatic inhibitory function in subjective memory complaint

“…Previous event‐related potential (ERP) studies have demonstrated the disruption of P50 SG in patients with AD (Jessen et al., 2001; Josef Golubic et al., 2017; Thomas et al., 2010). By magnetoencephalographic (MEG) recordings, we have previously found that compared to healthy older adults, patients with amnestic MCI exhibited reduced M50 and M100 SG function in the right inferior parietal lobule (IPL), as well as reduced M50 SG function in the left inferior frontal gyrus (Cheng et al., 2020). However, to the best of our knowledge, there have been no studies investigating the effects of SMC on auditory SG.…”