Patients with major depressive and bipolar disorders exhibited a significantly smaller increase in frontal oxygenated haemoglobin during a verbal fluency task compared to controls.
Case-Control
Do euthymic patients with mood disorders have altered cerebral haemodynamic responses to cognitive and physiological tasks compared to controls?
Hypofrontality in mood disorders may be associated with a poor response in cerebral blood vessels to neuronal and chemical stimuli.
BACKGROUND: Hypofrontality has been demonstrated in mood disorders by functional brain imaging methods such as positron emission tomography. However, the neurobiological basis of hypofrontality has not been well clarified. Near-infrared spectroscopy (NIRS) is a non-invasive technique for continuous monitoring of alterations in oxygenated (oxyHb) and deoxygenated (deoxyHb) haemoglobin using near-infrared light, which penetrates biological tissues. METHODS: We used NIRS during cognitive and physiological tasks to investigate alterations of haemoglobin oxygenation in the frontal region of euthymic patients with mood disorders (major depressive disorder (MD) and bipolar disorder (BP)) and in controls. RESULTS: The increase of oxyHb during a verbal fluency task was significantly less in the MD and the BP groups than in the controls. The MD group showed a significantly smaller decrease of oxyHb during hyperventilation than the controls. The BP group also showed a similar trend. CONCLUSIONS: These findings suggest that the hypofrontality in mood disorders may be associated with a poor response in the cerebral blood vessels to neuronal and chemical stimuli.
Matsuo et al. (Thu,) conducted a case-control in Mood disorders (major depressive disorder and bipolar disorder). Cognitive (verbal fluency) and physiological (hyperventilation) tasks monitored by NIRS vs. Controls was evaluated on Alterations of haemoglobin oxygenation (oxyHb) in the frontal region. Patients with major depressive and bipolar disorders exhibited a significantly smaller increase in frontal oxygenated haemoglobin during a verbal fluency task compared to controls.