99mTc-HMPAO SPECT Study of Cerebral Perfusion After Treatment with Medication and Electroconvulsive Therapy in Major Depression

Abstract

Compromised regional cerebral blood flow (rCBF) in major depressive disorder may be partly reversed by successful antidepressant treatment. However, it is not known if the reversal of rCBF compromise is dependant on the mode of antidepressant treatment. The current study aimed to address this question. Methods: Thirty-three patients (19 women and 14 men; mean age 6 SD, 53 6 16 y) with moderate major depressive disorder were studied before 6 wk of treatment with tricyclic antidepressants, selective serotonin reuptake inhibitors, or a course of electroconvulsive therapy, and 31 of these patients were also studied afterward. A comparison group of 25 healthy volunteers (13 women and 12 men; mean age, 49 6 15 y) were studied once. rCBF was assessed using 99m Tc-hexamethylpropyleneamine oxime SPECT. Images were analyzed using globally normalized statistical parametric mapping localized to the Montreal Neurologic Institute brain atlas. Results: Baseline rCBF was lower in depressed patients than in controls in the frontal cortex and subcortical nuclei bilaterally. A response to medication was associated with normalization of rCBF deficits, whereas a response to electroconvulsive therapy was associated with an additional rCBF decrease in the parietotemporal and cerebellar regions bilaterally. Conclusion: Hypoperfusion in major depressive disorder largely normalizes after a response to pharmacotherapy. Perfusion changes after a response to electroconvulsive therapy may follow a different course. Earl y functional neuroimaging studies comparing healthy and depressed subjects reported decreases in regional cerebral blood flow (rCBF) and metabolism typically in the frontal and prefrontal regions but also in temporal, parietal, and limbic-subcortical structures (1-3). More recent studies have presented a more diverse and complex picture, replicating but also extending the findings of earlier studies (1,2). These studies distinguished between ventral frontal and prefrontal regions that display increased metabolism or perfusion in depressed patients and more rostral regions within the cingulate gyrus and dorsolateral prefrontal cortex that show decreased perfusion. In other regions postulated to play a role in the pathophysiology of depression, such as the limbic and paralimbic regions and the basal ganglia, findings have been inconsistent (1,2). This diversity in brain imaging findings may reflect the heterogeneity between studies in age of subjects, group size, male-to-female ratio, subtype and severity of psychopathology, and medication status. The choice of imaging technique, radiopharmaceutical, acquisition parameters, and processing parameters also have varied considerably, as have the method of data analysis and choice of reference region.rCBF alterations in depression generally normalize after a response to treatment with medication, interpersonal psychotherapy, or a placebo (2,4) (but a different pattern of perfusion changes is seen in response to venlafaxine (5) or cognitive behavioral therapy (6)). Less consistency i...

Functional Imaging in Depression Population - Exploring the Unexplored

“…[19] Hypofrontality was shown to be associated with severe negative symptoms rCBF in depressed patients before treatment was lower than in healthy controls, and a response to medication was associated with an increase in cerebral perfusion. [20] Though there has been perfusion change between pre-treatment and post treatment groups, but in our study we were unable to find significant difference between these two groups ECD is a sensitive agent for detecting abnormalities characterized by neuronal necrosis, the present study suggests that it is less sensitive as a tracer for identifying the more subtle abnormalities of functional psychiatric disorders when compared with PET scan…”

Voxel-wise meta-analyses of brain blood flow and local synchrony abnormalities in medication-free patients with major depressive disorder

“…If the ar ticles were written in other languages, they were translated into English for assessment. In all, 5 SPECT studies, 8,9,[33][34][35] 8 PET studies, 6,7,36-41 1 ASL study 10 and 9 regional homogeneity studies [11][12][13]17,[42][43][44][45][46] met our inclusion criteria (Table 1). All these papers were written in English.…”

Resting State Blood Flow and Glucose Metabolism in Psychiatric Disorders

“…This findings is presumed to be related to clinical responsiveness (Prohovnik et al, 1986;Rosenberg et al, 1988;Guze et al, 1991). However, some studies have demonstrated significant increases in rCBF in several brains (Bonne et al, 1996;Kohn et al, 2007). These discrepancies might be due to several confounding factors, such as procedural-related factors including anesthetics and electrode replacements, or to varying durations between the termination of the ECT course and imaging scanning.…”