PANIC AND BRAINSTEM: CLUES FROM NEUROIMAGING STUDIES

La prestigiosa rivista internazionale CNS Neurological Disorders Drug Targets (Impact Factor 2012: 3,77) ha accettato per la pubblicazione un articolo sulle evidenze da studi sulle immagini cerebrali del coinvolgimento del tronco encefalico nel disturbo di panico firmato da Giampaolo Perna in collaborazione con colleghi Italiani.

Il titolo dell'articolo è "Panic and Brainstem: clues from neuroimaging studies” che ha come autori: Giampaolo Perna, Giuseppe Guerriero, Paolo Brambilla, Daniela Caldirola.

Abstract

One of the most influential theories has conceived unexpected panic attack (PA) as a primal defensive reaction to threat within the internal milieu of the body. This theory was based on findings suggesting the involvement of a dysfunctional respiratory regulation and/or abnormally sensitive central neural network of CO2/H+ chemoreception in PA. Thus, unexpected PA may be related to phylogenetically older brain structures, including brainstem areas, that process basic functions related to organism’s internal milieu. Brainstem represents a crucial area for regulation of homeostatic functions, including chemoreception and cardio-respiratory control. In addition, animal studies have suggested a potential role of the midbrain dorsal periaqueductal gray in the unconditioned defense reactions to proximal threats, including internal physical stimuli. Our aim was to specifically investigate the potential involvement of brainstem in panic disorder (PD) by a comprehensive review of the available neuroimaging studies. Results do not contradict a role of brainstem in PD and the most compelling evidence is the increased volume of brainstem in patients with PD. Secondly, brainstem serotonergic system seems to be involved in panic modulation with evidences of both altered serotonergic receptors and 5-HT transporter bindings. Finally, the only study investigating brain activation by fMRI during hypercapnic stimulation clearly showed brainstem activation. In conclusion, to date brain imaging studies are sufficient to make specific statements on the involvement of brainstem in PD. However they suggest a probable involvement of this brain area in panic psychopathology and support the key role of subcortical serotonergic system in panic pathogenesis.