Association between EEG alpha power and visuospatial function in obsessive–compulsive disorder

Abstract

The purpose of the present paper was to determine if frontal activity, measured as electroencephalogram alpha power, correlates with visuospatial functions in obsessive-compulsive disorder (OCD). Electroencephalography and the Rey-Osterrieth Complex Figure Test (RCFT) were performed on 23 patients meeting the Diagnostic and Statistical Manual of Mental Disorders (4th edn; DSM-IV) OCD criteria. After quantitatively analyzing EEG recordings taken over the frontal, temporal, parietal and occipital regions (F1, F2, T3, T4, P3, P4, O1 and O2), the log transformed absolute power values of the alpha frequencies of the regions were regressed with each RCFT index (copy, immediate recall and delayed recall score). On the frontal region (F1, F2), the RCFT copy score was found to be correlated with the alpha power with regression coefficients that had different directions according to hemisphere (F1, 5.62; F2, -5.26). The result that visuo-constructional ability represented by the RCFT copy score correlated with frontal activation as measured by decreased alpha power, supports the opinion that visuospatial dysfunction in OCD is not in the visuospatial memory per se but rather that it is mediated by executive function deficit. The opposite correlation directions indicate that greater left frontal activation correlates with a poorer RCFT copy score and that greater right frontal activation correlates with a better copy score. These relationships provide indirect evidence of the possibility that the main pathology of OCD is located in the left hyperfrontality and that the right hyperfrontality of OCD occurs by a compensatory mechanism.

Evidence-Based Medicine Evaluation of Electrophysiological Studies of the Anxiety Disorders

“…The authors interpreted left hyperfrontality as one of the primary pathologies in OCD. 47 Abnormalities in temporal regions in OCD were shown in a study by Locatelli et al4* Patients with OCD in the severe range (assessed using Y-BOCS), showed an increase of delta-1 and a decrease of alpha-2 power at rest compared to control subjects. In addition, temporal EEG activity was analyzed during olfactory stimulation and differences between patients and normal controls were indentified in the slower beta frequencies: normal subjects showed increased power to stirnulation, whereas OCD patients showed no modification or a slight decrease.…”

Alpha amplitude and phase locking in obsessive-compulsive disorder during working memory

“…Studies on OCD and alpha oscillations have focused on mostly resting alpha rhythms (Bucci et al, 2004;Karadag et al, 2003;Shin et al, 2004). It was reported that in a resting state, lower levels of alpha power were observed in the anterior and posterior brain regions in OCD patients (Bucci et al, 2004).…”

Executive Dysfunction in Obsessive-Compulsive Disorder and Anterior Cingulate-Based Resting State Functional Connectivity

“…Specifically, between-group comparisons of ACC-based rs-FCN between OCD and HC groups using five ACC sub-regions were examined based on the following brain-cognition relationships: caudal ACC (hub region of somatomotor network)-based rs-FCN vs. set-shifting with visuomotor sequencing (TMT-B),39 dorsal ACC (hub region of SN)-based rs-FCN vs. visuospatial organization (RCFT organization score),404142 supragenual ACC (hub region of ECN)-based rs-FCN vs. setshifting with strategic planning (WCST perseverative error),434445 and rostral ACC (hub region of DMN)-based rs-FCN vs. response inhibition (SCWT incongruent trial reaction time) 54647…”