The Food and Drug Administration (FDA) in the United States has issued one of their periodic proposals to reclassify ECT machines in a lower risk category (for treating depression in adults). The draft guidance document contains recommendations (nothing legally binding) on how manufacturers would be able to comply with the proposed “special controls”.
“An electroconvulsive therapy device is a prescription device, including the pulse generator and its stimulation electrodes and accessories, used for treating severe psychiatric disturbances by inducing in the patient a major motor seizure by applying a brief intense electrical current to the patient’s head.”
Manufacturers would be expected to test for biocompatibility of their machines, although this seems to be limited to the effect of electrodes on skin (nothing about the effect of the electric shock on the brain), as well as mechanical function. The document also has some suggestions on labeling, which include, as well as an operating manual, and recommendations on what physicians should tell patients. For example, “FDA recommends that physician labeling include a discussion of the benefits and risk to be considered when choosing the proper stimulation parameter.”
Four stimulus parameters are listed, with the “preferred modality of treatment to minimize cognitive/memory adverse events” being 1) brief-pulse current 2) unilateral electrode placement 3) stimulus intensity of less than 3 times seizure threshold with bilateral electrode placement (in case the psychiatrist rejects unilateral electrode placement) and 4) treatment at a rate of 2 times a week or less. The first and third parameters probably won’t cause many problems for psychiatrists as they are the standard forms of treatment in current use. The second and fourth are more problematical as bilateral electrode placement and 3 times a week treatments are probably more common in the US than unilateral, twice a week or less treatment. But of course these are only recommendations.
The FDA also proposes a special control that the labeling should include “prominently placed warnings”. For example
“Warning: ECT device use may be associated with: disorientation, confusion, and memory problems.’
“Warning: When used as intended this device provides short-term relief of symptoms. The long-term safety and effectiveness of eCT treatment has not been demonstrated.”
The FDA expands on the subject of memory loss, saying that ECT may be associated with “Anterograde (short-term) verbal memory” and “Retrograde (long-term) autobiographical memory”. It is not clear here whether short-term and long-term are being used to define anterograde and retrograde or whether they are suggesting that anterograde memory loss doesn’t last for long and retrograde does (and why only verbal?). In either case it would be misleading.
There follows a section of pre-treatment examination, monitoring, etc, and reporting of adverse events. Then the FDA suggests wording for informational material to be given to patients:
“The device applies a controlled electric current and prevents the electrical current (amplitude, waveform, duration of exposure) from exceeding limits specified by the manufacturer. The treatment involves the application of a controlled electric current that leads to a ‘convulsion’ or a ‘seizure’.”
I find it odd that it is thought necessary to tell patients that the manufacturer has set limits on, for example, the duration of exposure. And why the inverted commas around ‘convulsion’ or ‘seizure’? You get an electric shock; you have a seizure; the convulsive movements are dampened by a muscle paralyzing drug.
The FDA also recommends that patients should be told:
“For it to be effective, multiple treatments with ECT may be necessary.”
This again seems rather odd since ECT is invariably given in courses. Some people have just one treatment, but this is usually because they don’t want any more or because of complications. Or are they talking about maintenance treatment?
A paragraph on memory loss is included in the proposed information for patients:
“ECT treatment may be associated with disorientation, confusion and memory loss, including short-term (anterograde) and long-term (autobiographical) memory loss following treatment. These side effects tend to go away within a few days to a few months after the last treatment with ECT. However, some patients have reported a permanent loss of memories of person life events (i.e., autobiographical memory). Improvements in the way ECT is applied to patients currently, with controlled electric currents and electrode placement, can minimize but not completely eliminate, these risks.”
What exactly are these improvements? What is meant by a “controlled current”? Right from the beginning, nearly 80 years ago, psychiatrists controlled the current – they could select duration, voltage, etc. And the duration was much shorter in the olden days – often a fraction of a second compared to several seconds today. In terms of millicoulombs, the output stimulus, as the FDA calls it, is often greater today than it was in the past. Perhaps they mean brief-pulse current as opposed to sinusoidal? There is nothing new about this: brief pulse ECT is nearly as old as ECT itself, although some hospitals in the US were still using sinusoidal as recently as the 1990s – perhaps even more recently. As for electrode placement – most patients in the US still have bilateral ECT just like people did nearly 80 years ago. Neither is unilateral electrode placement new; it was first used in the 1950s.
The relationship between the different electrodes and waveforms and the results of treatment have been known for a long time. For example, in 1968 – that is nearly fifty years ago – the British Journal of Psychiatry published an article by M. Valentine, K.M.G. Keddie and D. Dunne “A comparison of techniques in electro-convulsive therapy”. The authors had looked at the effect of varying electrode placement (bilateral v unilateral) and waveform (sinus v brief pulse). They produced a table of how long it took patients to recover spontaneous respiration, consciousness and orientation after the seizure, and also recorded performance on a simple word recall test. On all measurements the unilateral brief pulse did best and the bilateral sinus wave did worst. In between came the unilateral sinus wave and the bilateral brief pulse, fairly close together and sometimes one and sometimes the other doing better. The mean time to recover consciousness following the shock (and that was what the authors called it) was one minute 37 seconds for the UL brief pulse group and seven minutes 33 seconds for the bilateral sine wave group. It took the unilateral brief pulse group a further 25 seconds to realize who they were, while the bilateral sine wave group took another three and a half minutes. Fifty years on, bilateral electrode placement remains the most commonly used form in Britain and in the US. As regards waveform: in Britain brief pulse waveform is used all the time, though the switch from sine wave was unhurried. In the US too brief pulse has been the most common form of treatment for many years, although I don’t know if there are still any psychiatrists using sine wave.
The FDA proposed guidelines apply only to the use of ECT as a treatment for depression in people aged over 18. Other uses would require clinical testing, and the last pages of the document describe recommendations for clinical trials.