The use of current source density as electrophysiological correlates in neuropsychiatric disorders: A review of human studies

Abstract

The use of current source density (CSD), the Laplacian of the scalp surface voltage, to map the electrical activity of the brain is a powerful method in studies of cognitive and affective phenomena. During the last few decades, mapping of CSD has been successfully applied to characterize several neuropsychiatric conditions such as alcoholism, schizophrenia, depression, anxiety disorders, childhood/developmental disorders, and neurological conditions (i.e., epilepsy and brain lesions) using electrophysiological data from resting state and during cognitive performance. Use of CSD and Laplacian measures has proven effective in elucidating topographic and activation differences between groups: i) patients with a specific diagnosis vs. healthy controls, ii) subjects at high risk for a specific diagnosis vs. low risk or normal controls, and iii) patients with specific symptom(s) vs. patients without these symptom(s). The present review outlines and summarizes the studies that have employed CSD measures in investigating several neuropsychiatric conditions. The advantages and potential of CSD-based methods in clinical and research applications along with some of the limitations inherent in the CSD-based methods are discussed in the review, as well as future directions to expand the implementation of CSD to other potential clinical applications. As CSD methods have proved to be more advantageous than using scalp potential data to understand topographic and source activations, its clinical applications offer promising potential, not only for a better understanding of a range of psychiatric conditions, but also for a variety of focal neurological disorders, including epilepsy and other conditions involving brain lesions and surgical interventions.

On the benefits of using surface Laplacian (current source density) methodology in electrophysiology

“…All of these favorable characteristics of the SL have been known for decades (Hjorth, 1975, 1980; Nunez, 1981; Nunez and Pilgreen, 1991; Law et al, 1993a, 1993b; Pascual-Marqui et al, 1988). The SL has been carefully investigated in comparative simulation studies (Babiloni et al, 1995, 1996; Nunez et al, 1994), its advantages and disadvantages have been discussed controversially (Biggins et al, 1991, 1992; Nunez and Westdorp, 1994; Perrin, 1992; Perrin et al, 1987), and many researchers have employed SL methods for clinical applications (e.g., Cincotti et al, 2004; McFarland, 2015; see review by Kamarajan et al, 2015) and basic research questions (e.g., Burle et al, 2015; Cohen, 2015; Giard et al, 2014; Kayser and Tenke, 2015b; Rangel-Gomez et al, 2015; Vidal et al, 2015) alike.…”

Genetic influences on functional connectivity associated with feedback processing and prediction error: Phase coupling of theta-band oscillations in twins

“…Then, Current Source Density Transform (CSD) was applied to the epoched dataset (Kayser and Logothetis, 2009; Kayser and Tenke, 2015) which implements a high-pass spatial filter that is useful for i) obtaining reference-independent data, ii) increasing topographical localization, iii) facilitating electrode-level connectivity analyses, and iv) attenuating volume-conduction effects. This method has been previously applied with data collected from participants with neuropsychiatric disorders (Kamarajan et al, 2015). …”

Potential biomarkers in personality disorders: current state and future research

“…Some of the clinical dimensions studied under the paradigm of endophenotypes are impulsivity, aggression, emotional information processing, attention, working memory, among others. Adittionally, the electrophysiological measures can be applied to diagnosis, prevention and treatment of the PD or various clinical conditions (Kamarajan & Porjesz, 2015).…”

“…This tools will help to discover new genes associated with these disorders, new treatments as well as for a wide range of clinical applications. (Kamarajan & Porjesz, 2015) It is important to mention that the development of neuroimaging techniques have been enhanced in recent years, but their implement on the research of PD represents a recent issue. Finally, a variety of new sophisticated statistical techniques could allow systematic research to highlight longitudinal aspects such as the cognitive development and the course of these disorders under research (Kamarajan & Porjesz, 2015 …”