Orbitofrontal cortex abnormality characteristic of deficit schizophrenia

By Lucy Piper, Senior medwireNews Reporter

The orbitofrontal cortex (OFC) appears to play an important role in the development of severe negative symptoms in people with deficit schizophrenia, researchers suggest.

They found that schizophrenia patients with and without deficit syndrome had similar distributions of resting regional cerebral blood flow in the medial and lateral prefrontal cortices that was reduced compared with mentally healthy controls.

But there was also significant hypoperfusion in the OFC of patients with deficit syndrome only.

Nobuhisa Kanahara, from Chiba University in Japan, and colleagues note that high negative symptoms did not solely explain the significant hypoperfusion in the OFC of the deficit syndrome group, and additional analyses in drug-free patients showed no effect of medication.

"Given the potential differences in emotional state among patients and the diverse potential roles of the OFC in humans, impairment in the OFC would be related not only with the profound negative symptoms, but also with other factors relevant to deficit syndrome, including diminished emotional state or cognitive deficits," they comment in Schizophrenia Research.

Using single photon emission computed tomography, the researchers measured regional cerebral blood flow in 33 patients with deficit syndrome, 40 patients with schizophrenia but without deficit syndrome, and 45 mentally healthy controls.

The significant differences in regional cerebral blood flow between patients with and without deficit syndrome was observed only in the OFC.

"The OFC is known to be closely related to evaluation, response, and learning with respect to a variety of stimuli," the researchers note.

"These impairments in the OFC in schizophrenia appear to be associated with the core disease pathophysiology.

"Furthermore, the present results suggested that the evident abnormality in the OFC could be characteristics of the deficit group, since the aberrant region remained significant in another comparison in which the authors controlled for negative symptoms," they conclude.

Licensed from medwireNews with permission from Springer Healthcare Ltd. ©Springer Healthcare Ltd. All rights reserved. Neither of these parties endorse or recommend any commercial products, services, or equipment.