Influence of comorbid obsessive-compulsive symptoms on brain event-related potentials in Gilles de la Tourette syndrome

Abstract

Approximately 30 to 50% of people suffering from Gilles de la Tourette Syndrome (GTS) also fulfill diagnostic criteria for obsessive-compulsive disorder (OCD). Despite this high degree of comorbidity, very few studies have addressed the question of obsessive-compulsive symptoms (OCS) in GTS patients using specific brain event-related potentials (ERP) responses. The aim of the current study was to quantify neurocognitive aspects of comorbidity, using ERPs. Fourteen adults with GTS (without OCD) were compared to a group of 12 participants with GTS and comorbid obsessive-compulsive symptoms (GTS+OCS), to a group of 15 participants with OCD and to a group of 14 control participants without neurological or psychiatric problems. The P200 and P300 components were recorded during a visual counting oddball task. Results showed intact P200 amplitude in all groups, whilst the P300 amplitude was affected differentially across groups. The P300 oddball effect was reduced in participants in both OCD and GTS+OCS groups in the anterior region. However, the P300 oddball effect was significantly larger in participants of the GTS group compared to all other groups, mostly in the parietal region. These findings suggest that adults with GTS are characterized by enhanced working memory updating processes and that the superimposition of OCS can lead to a reduction of these processes. The discrepancy between our findings and results obtained in previous studies on GTS could reflect the modulating effect of OCS on late ERP components.

The style of planning action (STOP) questionnaire in OCD spectrum disorders

“…High levels of muscle tension in TS are consistently reported in the literature (O'Connor, Gareau, & Borgeat, 1995). Reduced late cognitive related evoked potential findings have been linked to problems with response inhibition of thoughts and action and a tendency to overprepare under uncertainty (Thibault et al, 2008).…”

Functional neuroimaging in Tourette syndrome: recent perspectives

“…Overactivation of cortical areas has also been suggested in a couple of other studies. 75,76 It is hypothesized that this overactivation could be involved in both the control of tics and in the regulation of performance in adults with TS 71 as well as in faster retrieval of required motor programs. 76 Various EEG studies have examined the behavioral performance on several tasks.…”

Neural time course of threat-related attentional bias and interference in panic and obsessive–compulsive disorders

“…These factors raise the likelihood that differential results in the clinical groups were due to the differences in primary diagnoses between the clinical groups. Many previous ERP studies report or fail to mention comorbidities of clinical patients (Endrass, Klawohn, Schuster, & Kathmann, 2008;Johannes et al, 2001;Kim et al, 2003;Kim et al, 2006;Kivircik, et al, 2003;Schall, Schön, Zerbin, Eggers, & Oades, 1996;Thibault et al, 2008). Future research with nonmedicated participants with pure diagnoses and no comorbidities would be ideal, however practical and ethical difficulties and high comorbidities have contributed to the use of medicated participants and small sample sizes, particularly in OCD research (Muller & Roberts, 2005), and remain as ongoing challenges.…”