Evaluation of brain perfusion with technetium-99m bicisate single-photon emission tomography in patients with depressive disorder before and after drug treatment

Abstract

Depression is one of the most common psychiatric illnesses. Its influence on brain perfusion has been demonstrated, but conflicting data exist on follow-up after drug treatment. The aim of our study was to evaluate the effects of antidepressant drugs on regional cerebral blood flow (rCBF) in patients with depression after 3 weeks and 6 months of drug therapy. Clinical criteria for depression without psychosis were met according to psychiatric evaluation. Severity of depression was evaluated with the Hamilton Depression Rating Scale (HAMD) before every scintigraphic study. rCBF was assessed using technetium-99m bicisate (Neurolite) brain single-photon emission tomography in nine patients with severe depression before the beginning of antidepressant drug therapy and 3 weeks and six months after initiation of therapy. Only patients with no change in antidepressant medication during the study were included. No antipsychotic drugs were used. Cerebellum was used as the reference region. rCBF was evaluated for eight regions in each study in three consecutive transversal slices. Follow-up studies were compared with the baseline study. The mean HAMD score was 25.5 points initially, 16 at the second examination and 8.8 after 6 months. Global CBF was decreased compared with the reference region in drug-free patients. Perfusion of left frontal and temporal regions was significantly lower (P < 0.005) in comparison with the contralateral side. After therapy, a moderate decrease in perfusion was seen in the right frontal region (P < 0.05). Perfusion decreased further after 6 months in the right frontal (P < 0.005) and temporal regions (P < 0.01). The highly significant asymmetry in perfusion between the left and right frontal and temporal lobes almost disappeared during treatment. Our findings implicate dysfunction of the frontal and temporal cortex in clinically depressed patients before specific drug treatment. Clinical improvement and decreases in HAMD score after 3 weeks and after 6 months reflect the treatment effect on mood-related rCBF changes.

A Symptom-Specific Analysis of the Effect of High-Frequency Left or Low-Frequency Right Transcranial Magnetic Stimulation over the Dorsolateral Prefrontal Cortex in Major Depression

“…This functional asymmetry between right and left cortices associated with depression has been confirmed by several imaging studies that have shown a relative reduction of glucose metabolism or cerebral blood flow in the left prefrontal cortical region when compared to the right one [32][33][34] . Moreover, neurophysiological studies have shown a reduced excitability in the left hemisphere compared to the right [35] .…”

Changes in regional cerebral blood flow following antidepressant treatment in late‐life depression

“…On one hand, studies have documented an overall decrease in hemispheric mean cerebral blood flow (CBF) and/or rate of glucose metabolism in depression (Lesser et al, 1994;Kocmur et al, 1998). On the other hand, studies report a decrease/increase in regional CBF (rCBF) and/or glucose metabolism in particular regions of the brain.…”

Abstracts

“…The decreased Delta activity in the right hemisphere was also supported by SPECT findings (Kocmur, Milcinski, & Budihna, 1998). The high Beta activity (Beta4) increased bilaterally in the anterior cingulate and medial prefrontal gyrus for the depressed group occurred in the portion of the anterior cingulate referred to as the affective division and has been implicated in major depression (Bush, Liu, & Posner, 2000).…”