Hyper-frontality in an OCD patient - evidence from event-related potentials in a cued GO/NOGO task.

ABSTRACT

OBJECTIVE: The study aimed to evaluate the hyperactivity of the frontal lobes in a patient with obsessive-compulsive disorders. CASE DESCRIPTION A 21-year-old female met the diagnostic criteria of DSM-5 since her behaviour was characterized by a preoccupations with negative thoughts and by repetitive attempts to decrease or stop those behaviours. Two working hypotheses were tested to find neuromarkers of OCD and anxiety in the patient described. In agreement with the 'OCD hypothesis' an increase of the frontal beta activity and an increase of the parietalalpha activity pattern was found. The 'anxiety' hypothesis found confirmation in an increased left temporal P1 wave in response to the visual stimuli observed in ERPs. In all three conditions (EO, EC, GO/NOGO task), two characteristics were deviant from the normative average data in EEG spectra. First, an increase of frontal beta activity and the increase of parietal alpha activity was noted. The independent component analysis applied for 700 ms EEG fragments in GO and NOGO conditions revealed a strong activation over the central areas. CONCLUSIONS: Specific patterns of QEEG and ERPs, the increase of beta activity frontally, and the increase of parietal alpha activity pattern which produce hyper-frontality, might be useful in the diagnosis of an OCD patient. ERPs in a GO/NOGO task can be used in the assessment of functional brain changes in OCD patients.