Abnormal Auditory Processing and Underlying Structural Changes in 22q11.2 Deletion Syndrome

Abstract

The 22q11.2 deletion syndrome (22q11.2 DS), one of the highest genetic risk for the development of schizophrenia, offers a unique opportunity to understand neurobiological and functional changes preceding the onset of the psychotic illness. Reduced auditory mismatch negativity response (MMN) has been proposed as a promising index of abnormal sensory processing and brain pathology in schizophrenia. However, the link between the MMN response and its underlying cerebral mechanisms in 22q11.2 DS remains unexamined. We measured auditory-evoked potentials to frequency deviant stimuli with high-density electroencephalogram and volumetric estimates of cortical and thalamic auditory areas with structural T1-weighted magnetic resonance imaging in a sample of 130 individuals, 70 with 22q11.2 DS and 60 age-matched typically developing (TD) individuals. Compared to TD group, the 22q11.2 deletion carriers reveal reduced MMN response and significant changes in topographical maps and decreased gray matter volumes of cortical and subcortical auditory areas, however, without any correlations between MMN alteration and structural changes. Furthermore, exploratory research on the presence of hallucinations (H+\H−) reveals no change in MMN response in 22q11.2DS (H+ and H−) as compared to TD individuals. Nonetheless, we observe bilateral volume reduction of the superior temporal gyrus and left medial geniculate in 22q11.2DSH+ as compared to 22q11.2DSH− and TD participants. These results suggest that the mismatch response might be a promising neurophysiological marker of functional changes within the auditory pathways that might underlie elevated risk for the development of psychotic symptoms.

Alterations in the volume of thalamic nuclei in patients with schizophrenia and persistent auditory hallucinations

“…In addition, there are reductions of the MD connectivity in patients with schizophrenia ( Parnaudeau et al, 2013 ). Similarly, a couple of studies found reductions in the volume of the MGN in 22q11.2 deletion syndrome patients, a genetic disorder, which confers high risk for schizophrenia and frequently courses with AH ( Cantonas et al, 2021 , Mancini et al, 2020 ).…”

Neural integration and segregation revealed by a joint time-vertex connectome spectral analysis

“…The impedance was kept below 30 kΩ for all electrodes and below 10 kΩ for the reference and ground electrodes. The preprocessing steps were performed by using the free academic software Cartool (31)(https://sites.google.com/site/cartoolcommunity/home) as previously described (24,30,32,33). In detail, the number of electrodes was reduced from 256 to 204 by eliminating the noisy electrode signals from the cheeks and neck.…”

Oscillatory Neural Signatures of Visual Perception Across Developmental Stages in Individuals With 22q11.2 Deletion Syndrome

“…The pre-processing steps, including band-pass filtering , exclusion of artefactual periods, interpolation of noisy channels, and re-referencing were performed by using the free academic software Cartool (45,51). For further details: Supplementary Materials.…”