[Alteration of cerebral blood flow by modified electroconvulsive therapy in major depression]

Modified electroconvulsive therapy (mECT) aims to improve major depression, giving an electronic stimulation to a patient in order to make tonic-clonic convulsion. Elevation of regional cerebral oxygen saturation (rSO2) was reported just after stimulation. Increase of oxygen consumption in brain is compensated by increase of cerebral blood flow. Oxygenation and blood flow over the entire brain are evaluated by measuring rSO2 at forehead. We followed alteration of rSO2 at each mECT.

rSO2 was measured by INVOS 5100 (Edwards Lifesciences). Patients had Somasensor placed at the right and left forehead, rSO2 was measured from before and after mECT. After general anesthesia induction, patients were stimulated by Tymatron SYSTEM IV (Somatics, America). Intensity of stimulation was decided by a single psychiatrist. We showed rSO2 values as follows: before stimulation (before), minimum value after stimulation (mini) and maximum value after stimulation (max). Hamilton depression scale (HAM-D) was used for severity of depression.

All patients showed improved HAM-D. The values of (max-before)/before of rSO2 increased at the end of the therapy.

We suggested that the response of cerebral vasculatures for electroconvulsive stimulation was improved as depression was improved.