22q11.2 Deletion Syndrome Is Associated With Impaired Auditory Steady-State Gamma Response

Abstract

BackgroundThe 22q11.2 deletion syndrome confers a markedly increased risk for schizophrenia. 22q11.2 deletion carriers without manifest psychotic disorder offer the possibility to identify functional abnormalities that precede clinical onset. Since schizophrenia is associated with a reduced cortical gamma response to auditory stimulation at 40 Hz, we hypothesized that the 40 Hz auditory steady-state response (ASSR) may be attenuated in nonpsychotic individuals with a 22q11.2 deletion.MethodsEighteen young nonpsychotic 22q11.2 deletion carriers and a control group of 27 noncarriers with comparable age range (12–25 years) and sex ratio underwent 128-channel EEG. We recorded the cortical ASSR to a 40 Hz train of clicks, given either at a regular inter-stimulus interval of 25 ms or at irregular intervals jittered between 11 and 37 ms.ResultsHealthy noncarriers expressed a stable ASSR to regular but not in the irregular 40 Hz click stimulation. Both gamma power and inter-trial phase coherence of the ASSR were markedly reduced in the 22q11.2 deletion group. The ability to phase lock cortical gamma activity to regular auditory 40 Hz stimulation correlated with the individual expression of negative symptoms in deletion carriers (ρ = −0.487, P = .041).ConclusionsNonpsychotic 22q11.2 deletion carriers lack efficient phase locking of evoked gamma activity to regular 40 Hz auditory stimulation. This abnormality indicates a dysfunction of fast intracortical oscillatory processing in the gamma-band. Since ASSR was attenuated in nonpsychotic deletion carriers, ASSR deficiency may constitute a premorbid risk marker of schizophrenia.

Musical auditory processing, cognition, and psychopathology in 22q11.2 deletion syndrome

“…However, DTT scores were not significantly associated with Gold‐MSI scores after controlling for age and sex, indicating that the impairments in pitch discrimination as measured by the DTT are less likely to be a direct result of reduced musical engagement in this population. Rather, deficits in perceptual abilities and the DTT in our sample exist alongside previously described abnormalities in general auditory processing in 22q11DS compared to controls as evidenced by poorer P50 response gating, altered mismatch negativity response, and an attenuated auditory steady‐state response at 40 Hz (Baker, Baldeweg, Sivagnanasundaram, Scambler, & Skuse, ; Larsen, Morup, et al, ; Larsen, Pellegrino, et al, ; Zarchi et al, ). In the general population, enhanced mismatch negativity has also been linked to musical expertise and greater depression risk (Bonetti, Haumann, Vuust, Kliuchko, & Brattico, ; Brattico et al, ; Nikjeh, Lister, & Frisch, ).…”

Transcranial direct current stimulation over the sensory‐motor regions inhibits gamma synchrony

“…Although the 40 Hz sound induced a consistent 40 Hz power and ITPC increase in all conditions (Figure ), the whole cortex analysis did not unveil any significant effect for Power, but only for ITPC (Figure ). ITPC is known to provide a reliable measure of the degree of gamma synchronization externally driven and is much more sensitive than Power (Larsen et al, ). While it is possible that the cluster‐permutation statistics applied in this study was too conservative with a chance of false negative, our results suggest that tDCS has a selective effect on gamma synchronization as measured by ITPC.…”

“…To this purpose, we took advantage of MEG. This technique allows measuring cortical activity noninvasively, with high temporal resolution, with better spatial resolution than EEG (Chowdhury et al, ; Hedrich, Pellegrino, Kobayashi, Lina, & Grova, ; Larsen et al, ; Pellegrino et al, ; Pellegrino, Tomasevic, Herz, Larsen, & Siebner, ; von Ellenrieder et al, ). This technique is also especially suitable in the context of off‐line tDCS as it does not require the application of electrodes on the scalp and has no impact on tDCS montage (Pellegrino et al, ).…”

Bilateral Transcranial Direct Current Stimulation Reshapes Resting-State Brain Networks: A Magnetoencephalography Assessment

“…Conversely, robust and consistent evidence suggests that also neurological conditions translate into changes of brain activity and synchronization [ 41 ]. For instance, an impairment of cortical synchronization is often found at the first stages of neuropsychiatric conditions, up to the healthy subjects who own an increased risk [ 42 – 44 ]. More importantly, clinical recovery seems to be associated with changes of cortical rhythms and synchronization [ 45 – 47 ].…”