January 2007 | Back to Table of Contents
Clinical and Health Affairs
Decreased Memory Loss Associated with Right Unilateral Ultra-Brief Pulse Wave ECT
By Suck Won Kim, M.D., Jon E. Grant, J.D., M.D., Barry R. Rittberg, M.D., John E. Simon, M.D., Craig J. Vine, M.D., and S. Charles Schulz, M.D.
Abstract
The purpose of this brief article is to share with our colleagues in the psychiatric community and other physicians information about the efficacy of an emerging new method of electroconvulsive therapy (ECT) that shows advantages over existing treatments for depression. Patients treated with the method, ultra-brief pulse wave ECT, have less memory loss and confusion than those treated with longer-duration ECT.
Minnesota Department of Health data show that 542 persons committed suicide in 2005 (a rate of 10.56/100,000 population).1 Many of these individuals were, no doubt, refractory to various drug treatments and counseling. Although data consistently support the efficacy of electroconvulsive therapy (ECT) for treatment of depression, many physicians and patients avoid it because of its potential to cause significant memory loss.
Through large-scale National Institute of Mental Health, National Institutes of Health–funded studies over the past 25 years, researchers at Columbia University, led by Harold Sackeim, have refined the treatment methods and ECT hardware. This group and others have provided empirically tested evidence for the indication, frequency, dose, and total number of ECT treatments required for an optimal therapeutic outcome. They also have provided valuable information on the short- and long-term side effects and risks associated with ECT.2
Most recently, Sackeim’s group reported cognitive and affective consequences of right unilateral ultra-brief pulse wave ECT.2 Substantial basic physiological research indicates that the optimal width of a pulse stimulus to produce neuronal depolarization is on the order of 0.1 ms to 0.2 ms. Yet, traditional brief-pulse stimuli range from 0.5 ms to 2.0 ms. In essence, patients may be receiving pulse widths that are an order of magnitude above that necessary to produce depolarization, with substantial stimulation occurring during neuronal refractory periods.
Previous studies of ultra-brief pulse stimulation have been inconsequential because they used nonoptimal stimulation parameters (dosage relative to seizure threshold impacts on efficacy) and ultra-brief stimuli that were inefficient because they were excessively short in duration.2 In this new study, Sackeim and colleagues kept pulse frequency at a low level (20 Hz to 30 Hz) and used treatment duration as the primary variable to manipulate dosage (up to 8 seconds, which is twice as long as the duration for traditional bilateral ECT).
They found the following:
1) Ultra-brief stimulation is substantially more efficient in seizure induction, with the charge at seizure threshold at least 3 times less with the ultra-brief pulse;
2) A dramatic difference in the cognitive effects of ultra-brief and standard pulse-width stimulation, the advantage for ultra-brief stimulation being greater than that for right unilateral versus bilateral ECT;
3) Seizure manifestations are distinct with ultra-brief stimulation, with reduced ictal EEG amplitude and less postictal suppression; and
4) Most surprising, ultra-brief right unilateral ECT and long pulse-width right unilateral and bilateral ECT appear to be equivalent in efficacy.2 In contrast, ultra-brief bilateral ECT appears to lack significant antidepressant properties.
Since this first report, the authors have conducted further research on the subject, the results of which are to be reported in the near future.3 Both Sackeim and Columbia’s D.P. Devanand
recommended right unilateral ultra-brief ECT, and Devanand described the difference between that and traditional ECT as being like “day and night.”4
Ten months ago, after careful research on the subject and consultation with Sackeim and Devanand, we embarked on ultra-brief pulse wave ECT at the University of Minnesota Hospital, Fairview. Collectively, we have administered more than 2,500 ultra-brief pulse wave ECT treatments. Results have been impressive. All inpatient psychiatrists have uniformly noticed significantly decreased memory loss among patients, and postanesthesia recovery room nurses have uniformly reported that the post-ECT period of confusion was dramatically reduced. A good number of patients reported no noticeable memory loss after the completion of 8 treatments, a typical number required in an ECT series. Patients on the inpatient units who had ultra-brief pulse wave ECT treatments have talked with others, and since then, the number of requests for the treatment have increased dramatically.
Unilateral ECT has had problems in the past, namely, that it is not as effective as bilateral ECT. We have had difficulty inducing or maintaining seizures in some cases. For those patients, we use hyperventilation, intravenous caffeine, and/or an alternative anesthetic such as etomidate. In contrast to barbiturates, such as thiopental or methohexital, etomidate does not raise the seizure threshold. Studies have shown that etomidate increases the duration of the seizure compared with methohexital or other traditional induction drugs.5 Etomidate, however, is known to cause reversible adrenal suppression and should not be used routinely.6 MM
Suck Won Kim is a professor, Jon Grant is an associate professor, Barry Rittberg is an assistant professor, John Simon is a clinical associate professor, Craig Vine is an assistant professor, and S. Charles Schulz is a professor in and head of the department of psychiatry at the University of Minnesota.
References
1. Personal communication with Judy Palermo, Minnesota Center for Health Statistics, Minnesota Department of Health.
2. Sackeim HA, Prudic J, Nobler MS, Lisanby SH, Devanand DP, Peyser S. Ultra-brief pulse ECT and the affective and cognitive consequences of ECT. J ECT. 2001;17:77 (abstract).
3. Personal communication with DP Devanand.
4. Personal communication with HA Sackeim and DP Devanand.
5. Conca A, Germann R, Konig P. Etomidate vs. thiopentone in electroconvulsive therapy. An interdisciplinary challenge for anesthesiology and psychiatry. Pharmacopsychiatry. 2003;36(3):94-7.
6. Allolio B, Dorr H, Stuttmann R, Knorr D, Engelhardt D, Winkelmann W. Effect of a single bolus of etomidate upon eight major corticosteroid hormones and plasma ACTH. Clin Endocrinol (Oxf). 1985;22(3):281-6.