Delta and theta oscillations as risk markers in adolescent offspring of alcoholics

Abstract

Background-Visual P300 is consistently lower in alcohol dependent individuals, their offspring and subjects at risk. Delta and theta event related oscillations (ERO) are the major contributors to the P300 signal. The total and evoked power in delta and theta bands in the 300 to 700 millisecond post-stimulus window (corresponding to the zone of P3 maxima) was compared between adolescent offspring of alcoholics (high-risk) and age-matched normal controls (low-risk), to assess the utility of the risk markers.Methods-EEG was recorded during the performance of visual oddball task. The S-Transform algorithm decomposed the EEG signals into different frequency bands and the group differences in total and evoked power in the oscillatory responses during the P300 time window (300 to 700 ms) were analyzed using a multivariate design. Similar analysis was performed on P300 peak amplitudes for the target.Results-The high-risk group showed significantly lower parietal post-stimulus evoked and total power in the delta band for targets. A decrease in total power was seen centrally and parietally in theta band. The P300 peak amplitude in the parietal electrodes was also significantly lower in the high-risk group.Conclusions-The decreased total theta power and total and evoked delta power for visual targets in high risk individuals may serve as an endophenotypic marker in the development of alcoholism and other disinhibitory disorders. The differences seen between the offspring of alcoholics and controls may have a cholinergic basis. The ERO measures appear to be more robust than the P300 amplitude in differentiating the groups.

Effects of Memantine on Event-Related Potential, Oscillations, and Complexity in Individuals With and Without Family Histories of Alcoholism

“…As expected, central and parietal theta activity for FHP subjects was lower during placebo, consistent with prior studies reporting decreased theta power in a visual P300 task (Rangaswamy et al, 2007), and during the no-go condition (Kamarajan et al, 2006) of go/no-go tasks. Low theta activity may be a marker of circuit dysfunction associated with impaired learning, memory, and selective attention (Klimesch et al, 2001;Yordanova and Kolev, 1998).…”

“…S-transform (Stockwell et al, 1996) is an effi cient method for extracting estimates of localized power of nonstationary evoked potentials and has been extensively used in prior alcoholism studies (Kamarajan et al, 2006;Padmanabhapillai et al, 2006;Rangaswamy et al, 2007). S-transform is a generalization of the short-time Fourier transform with a variable-length Gaussian window function sliding across time at different frequency scales.…”

“…The NMDA antagonist ketamine attenuates theta and increases gamma activity (Lazarewicz et al, 2010), providing evidence for the role of NMDARs in mediating the balance between theta and gamma oscillations. Abnormal low-frequency amplitudes in visual oddball Rangaswamy et al, 2007) and go/no-go paradigms (Kamarajan et al, 2006) are reported in FHP individuals. A comprehensive review of ERO-based studies in alcoholism can be found in Pandey et al (2012).…”

Neurophysiological maturation in adolescence – vulnerability and counteracting addiction to alcohol

“…It was confirmed that an increase in amplitude and power of Beta waves presents the features of electrophysiological endophenotype in the form of an increased predisposition for addiction to alcohol. It must also be said that this endophenotype is accompanied by disorders of behaviour, already in childhood, and more frequent use of psychoactive substances in adolescence, and more frequent anti-social behaviours and attitudes [48,49,50,51].…”

Further Analyses of Genetic Association Between GRM8 and Alcohol Dependence Symptoms Among Young Adults

“…Theta oscillations are reduced in alcohol-dependent individuals (Jones et al, 2006) and in the adolescent offspring of alcoholics (Rangaswamy et al, 2007), suggesting that they may be a biological marker of the predisposition to alcohol dependence.…”