Dissertation committee:
Παπαγεωργίου Χαράλαμπος, Καθηγητής, Τμήμα Ιατρικής, ΕΚΠΑ
Αγγελόπουλος Ηλίας, Καθηγητής, Τμήμα Ιατρικής, ΕΚΠΑ
Δρούκας Βύρων, Ομότιμος Καθηγητής, Τμήμα Οδοντιατρικής, ΕΚΠΑ
Σμυρνής Νικόλαος, Καθηγητής, Τμήμα Ιατρικής, ΕΚΠΑ, Επιβλέπων
Μιχόπουλος Ιωάννης, Αναπληρωτής Καθηγητής, Τμήμα Ιατρικής, ΕΚΠΑ
Μασδράκης Βασίλειος, Αναπληρωτής Καθηγητής, Τμήμα Ιατρικής, ΕΚΠΑ
Τζαβέλλας Ηλίας, Eπίκουρος Καθηγητής, Τμήμα Ιατρικής, ΕΚΠΑ
Summary:
BACKGROUND: Patients with Body Dysmorphic Disorder (BDD) exhibit differential attentional mechanisms compared to healthy subjects. The exact nature of this differentiation is unclear. To this end, EEG responses to prepulse inhibition (PPI: reflecting attentional modulation) and prepulse facilitation (PPF: indicating orienting activation) were recorded and analyzed. The aim of this study was to compare the respective neural oscillations associated with PPI (prepulse-pulse interval: 30-500msec) and PPF (prepulse-pulse interval: 500-2000msec) in BDD vs. healthy controls.
MATERIALS AND METHODS: Event-related EEG oscillations elicited by PPI and PPF conditions have been examined in a sample of patients with BDD (N=30), matched and in healthy controls (N=25). Each session consisted of 51 randomly presented trials (26 PPI and 25 PPF trials). Neural oscillations elicited by PPI and PPF conditions.
Yale-Brown Obsessive- Compulsive Scale for BDD (BDD-YBOCS), Body Dysmorphic Disorder Examination, Dysmorphic Concern Questionnaire (DCQ) and Brown Assessment of Belief Scale (BABS), were also administered. Statistical significant difference was found between groups in scores of psychometric scales.
RESULTS: Analysis of the power spectrum in response to PPI and PPF, revealed that, the BDD patient group exhibited higher theta-1 oscillations (indication of disrupted thalamo-cortical activation) and reduced beta-1 oscillations (indication of top-down-controlled processing during attentional orienting).
CONCLUSION: These results offer novel contributions to the attentional neural mechanisms of BDD patients, and highlight the potential of using event-related EEG oscillations, to gain a better understanding of BDD.
Keywords:
Body Dysmorphic Disorder, Auditory-evoked oscillations, Prepulse Inhibition (PPI), Prepulse Facilitation (PPF), Attention, Orienting activation