Brain blood flow in anxiety disorders. OCD, panic disorder with agoraphobia, and post-traumatic stress disorder on 99mTcHMPAO single photon emission tomography (SPET)

Abstract

Background: We compared regional cerebral blood flow (rCBF) in three groups of patients with DSM-III-R anxiety disorders.

Method: Fifteen patients with obsessive -compulsive disorder (OCD), 15 with panic disorder with agoraphobia (PA), and 16 with post-traumatic stress disorder (PTSD) and a similar group of healthy controls were assessed on brain-dedicated high-resolution SPET.

Results: MANOVA revealed significant rCBF differences between diagnostic groups (F = 4.4; d.f. = 3, 57; P = 0.007) and between cerebral regions (F = 6.4; d.f. = 1, 57; P = 0.01) in OCD and PTSD compared with PA and healthy controls, limited to bilateral superior frontal cortices and right caudate nuclei. Whole brain blood flow correlated positively with anxiety (r = 0.24, n = 46, P = 0.05). Beck depression scores correlated significantly negatively with left caudate rCBF (r = -0.24, n = 46, P = 0.05) and right caudate rCBF (r = -0.31, n = 46, P = 0.02). PTSD syndrome severity correlated significantly negatively with the left caudate (r = -0.49, n = 16, P = 0.03) and with right caudate rCBF (r = -0.7, n = 16, P = 0.001).

Conclusions: Functional rCBF differences in anxiety disorders could relate to repetitive, intrusive, distressing mental activity, prominent in both OCD and PTSD.