Neurophysiological differences between @entity1 clinically at high risk for XXXX and neurotypical controls - first steps in development of a biomarker.

@entity1 @entity146 @entity161 @entity2483 @entity922
BACKGROUND: @entity161 is a severe, disabling and prevalent @entity146 without cure and with a variable, incomplete pharmacotherapeutic response. Prior to onset in adolescence or young adulthood a prodromal period of abnormal symptoms lasting weeks to years has been identified and operationalized as @entity922 ( @entity922 ) for @entity161 . However, only a minority of subjects prospectively identified with @entity922 convert to @entity161 , thereby limiting enthusiasm for early intervention(s). This study utilized objective resting electroencephalogram (EEG) quantification to determine whether @entity922 constitutes a cohesive entity and an evoked potential to assess @entity922 cortical auditory processing. METHODS: This study constitutes an EEG-based quantitative neurophysiological comparison between two unmedicated subject groups: 35 neurotypical controls (CON) and 22 @entity922 @entity1 . After artifact management, @entity2483 ( @entity2483 ) identified EEG spectral and spectral coherence factors described by associated loading patterns. Discriminant function analysis (DFA) determined factors' discrimination success between subjects in the CON and @entity922 groups. Loading patterns on DFA-selected factors described @entity922 -specific spectral and coherence differences when compared to controls. The frequency modulated auditory evoked response (FMAER) explored functional CON- @entity922 differences within the superior temporal gyri. RESULTS: Variable reduction by @entity2483 identified 40 coherence-based factors explaining 77.8  % of the total variance and 40 spectral factors explaining 95.9  % of the variance. DFA demonstrated significant CON- @entity922 group difference (P <0.00001) and successful jackknifed subject classification (CON, 85.7  %; @entity922 , 86.4  % correct). The population distribution plotted along the canonical discriminant variable was clearly bimodal. Coherence factors delineated loading patterns of altered connectivity primarily involving the bilateral posterior temporal electrodes. However, FMAER analysis showed no CON- @entity922 group differences. CONCLUSIONS: @entity922 subjects form a cohesive group, significantly separable from CON subjects by EEG-derived indices. Symptoms of @entity922 may relate to altered connectivity with the posterior temporal regions but not to primary auditory processing abnormalities within these regions.
