Seizure threshold estimation by formula method: a prospective study in unilateral ECT.

Formula methods of estimating seizure threshold in bilateral electroconvulsive therapy (ECT) have been successful in 75% (at the first ECT) and 80% (at the sixth ECT) of treatments (Gangadhar et al., 1998). This study showed the same results for unilateral (UL) ECT patients. Its aim was to compare formula and titration methods for threshold determination. The seizure threshold (dependent variable) was determined by the titration method used at the first ECT in consecutive consenting patients (n = 80) prescribed UL ECT under general anesthesia. The independent variables were age, gender, diagnosis, illness severity, concurrent drugs, head circumference, and inion-nasion distance. Forward, step-wise, linear regression analysis showed age as the only significant predictor of seizure threshold (15% of variance). A formula based on regression analysis was prospectively applied in an independent sample (n = 30) of patients receiving UL ECT using the titration method for threshold determination. The results calculated a higher threshold than the actual threshold used in 14 patients, a threshold level in 8 patients, and below threshold in 8 patients. Formula-based estimates would have been successful in 22 (73%) patients, but the majority of them would have received higher than the recommended stimulus dose. Titration is the method preferred for clinical use. However, if a patient's doctor wishes to use the formula-based method, he or she should do so with specific considerations.

Cardiovascular response during ECT: a cross-over study across stimulus conditions.

This study examined the effect of stimulus conditions on rate pressure product (RPP) during ECT. Seizure duration as well as baseline, ictal, and postictal RPP were recorded in 28 patients who received ECT under four stimulus conditions (unilateral threshold, unilateral suprathreshold, bilateral threshold, and bilateral suprathreshold). Seizure duration did not differ between the stimulus conditions. RPP significantly rose from baseline under every stimulus condition. Both ictal and postictal RPP values were different between stimulus conditions (one-way repeated-measure analysis of variance). Pair-wise comparisons showed that unilateral threshold ECT produced significantly lower RPP than unilateral suprathreshold and bilateral suprathreshold ECT conditions. The selective differences in RPP during ECT as well as their correspondence with the known therapeutic potency of ECT under these stimulus conditions suggest that RPP may be a potential index of ECT's therapeutic potency.

Discontinuation of antidepressant drugs during electroconvulsive therapy: a controlled study.

BACKGROUND: The concurrent use of antidepressant drugs with ECT is recommended by a recent ECT guideline. The study aimed to examine differential therapeutic and side effect responses when antidepressants are discontinued or not during ECT. METHODS: This study compared the effectiveness and side effect profile of unilateral ECT with antidepressant drugs (Group-1) or unilateral ECT with drug placebo (Group-2) in 30 major depressive disorder (DSM-IV) patients on antidepressants using a prospective randomised trial. Hamilton Rating Scale for Depression (HRSD), Montgomery Asberg Depression Rating Scale (MADRS), UKU scale, Columbia ECT side effect check list were used. The assessments were carried out before starting ECTs and at fixed intervals thereafter for four weeks. In addition, at six weeks a follow-up assessment was carried out using HRSD. ECTs were stopped after four weeks or earlier if patient obtained HRSD scores <8 and remained so for one week. RESULTS: Continuation of antidepressant drugs with ECT conferred no therapeutic advantage. Barring tricyclic antidepressant induced anticholinergic side effects, no differential side effect profile was noted. At follow-up none relapsed in Group-2 and the mean HRSD scores between the groups did not differ. LIMITATION: The antidepressant treatment prior to ECT was uncontrolled. In addition, the design was not strictly double-blind. CONCLUSION: The study failed to support an advantage with antidepressant continuation during an ECT course in major depressive disorder.

Motor seizure monitoring during electroconvulsive therapy.

BACKGROUND: The occurrence of a seizure during electroconvulsive therapy (ECT) should be confirmed. Most clinicians use motor seizure monitoring alone and recent guidelines have not considered electroencephalogram (EEG) monitoring mandatory. AIMS: To examine the potential pitfalls of motor seizure monitoring. METHOD: Consenting consecutive patients (n = 232) were prospectively studied at the first ECT session using both motor and EEG seizure monitoring. It was ensured (by titration) that all the patients had an adequate EEG seizure. Adequate and prolonged seizures were defined according to the latest recommendations of the Royal College of Psychiatrists. RESULTS: Motor seizure was inadequate in 15 (7%) of patients. EEG seizure was prolonged in 38 (16%) of patients. Fifteen patients (39%) did not have a prolonged motor seizure. Motor seizure correlated well (r = 0.8, P < 0.001) with EEG seizure when the latter was adequate, but not when prolonged (r = 0.12, P > 0.5). CONCLUSIONS: Motor seizure monitoring without EEG is undependable. The study provides a rational basis for the Royal College of Psychiatrists' definition of prolonged EEG seizure.

Comparison of therapeutic efficacy of ect and imipramine : a randomized controlled trial.

Efficacy studies comparing ECT and tricyclics in depression have had methodological limitations. This study compared EC T and imipramine (IMN) prescribed as the first line of treatment in major depression, Drug-naive, consenting, DSM-IV major depression patients (n=28), were randomized to receive either bilateral ECTs or IMN (225 mg/d) for four weeks. Severity of depression was scored at twice weekly intervals. Subjective side effects were scored at second and fourth week. Patients had significant reductions in depression scores over time but there were no differences between the two treatment groups. The rate of antidepressant response did not significantly differ between the two groups. ECT group had significantly fewer side effects. IMN offered therapeutic response comparable to ECT without compromising on the speed of antidepressant response, but caused more side effects.

Atropine premedication and the cardiovascular response to electroconvulsive therapy.

A report by the Royal College of Psychiatrists recommended avoiding atropine premedication during electroconvulsive therapy (ECT). We have examined the cardiovascular effects of ECT with or without atropine premedication. Consenting patients (n = 30) were allocated randomly before their third ECT session to receive atropine or no premedication. The rate pressure product (RPP) was recorded before anaesthesia, before ECT stimulus and at 1-min intervals thereafter for 5 min. Patients who did not receive atropine had significantly lower RPP values after all stimulus recordings. Administration of atropine or not explained 32% of the variance of summated RPP after the stimulus. There was no clinically significant bradyarrhythmia in those who did not receive atropine. Our findings support the recommendation of the Royal College of Psychiatrists. The study suggests that when threshold determination is not needed, avoiding atropine effectively contains potentially harmful cardiovascular responses.

Acute post-ECT cardiovascular response: a comparison of threshold right unilateral and bilateral ECT.

The effect of electrode placement on cardiovascular responses was studied. Rate pressure product and diastolic blood pressure before anesthesia and 30 s after electroconvulsive therapy (ECT) seizure were recorded. Recordings were made at the first (threshold ECT) session in 124 bilateral ECT (BLECT) and 95 unilateral ECT (ULECT) consenting patients. Postictal rate pressure product (RPP) was significantly higher after BLECT than ULECT. Mean increase in RPP from pre- to postictal phase was 31% in the former. The corresponding change with ULECT (20%) was significantly smaller. In the stepwise, multiple regression model, pre-ECT RPP, age, and stimulus laterality significantly contributed to postictal RPP. No cardiovascular complications occurred in any of the 219 ECT sessions.