You've probably heard this before, but due to reader feedback this post and all future posts will be shorter (less than five minutes).
We are almost to the end of our current theme of depression. Back on day # 28 we gave an overview of how to treat depression without medications. During that lesson we briefly discussed interventional treatments to include ECT, TMS, and DBS. Today we will provide additional information about ECT to include mechanism of action, indications, clinical pearls, and side effects.
Today's Content Level: Intermediate, Advanced
ELECTROCONVULSIVE THERAPY (ECT)
Introduction
Formerly known as shock therapy.
Involves a brief electrical current to the brain to induce a generalized seizure.
Patient is under general anesthesia.
Proven to be a very effective and safe treatment, however it remains stigmatized and controversial due to misinformation and outdated perceptions of the treatment.
Mechanism
The exact mechanism of ECT to treat mental disorders is not completely known, but the following are hypotheses based on recent studies:
Increases release of monamine neurotransmitters (dopamine, serotonin, norepinephrine).
Stimulates a neuroendocrine response (release of endorophins, prolactin, TSH).
Increases anticonvulsant properties which may be therapeutic.
Increases metabolic activity in the frontal and cingulate cortex.
Changes brain connectivity.
Possibly induces neurogenesis (studies have shown increased gray matter and cortical thickness). 1
Indications
Severe depression or treatment resistant depression
Major depression with psychotic features
Catatonia
Neuroleptic malignant syndrome (NMS)
Some evidence in bipolar, schizophrenia, and schizoaffective disorder
Technique
Physiologic functions monitored during ECT: vital signs, blood oxygen saturation, cardiac rhythms (ECG), and brain electrical activity (EEG).
Electrode placement can be bilateral/bitemporal (↑↑antidepressant, ↑↑memory loss impairment), right unilateral (↑antidepressant, ↓memory loss), or bifrontal (↑antidepressant, ↓memory loss).
This is an advanced topic, but the actual technique of the ECT involves preoxygenation, anesthetic that does not interfere with the seizure (methohexital or propofol or ketamine), muscle relaxant (typically succinylcholine), +/- anticholinergic medication (atropine or glycopyrollate). See UpToDate for more advanced info.
Clinical Pearls
Standard practice in the U.S. is to give treatments three times per week. Twice a week for elderly patients or daily treatment for urgently ill (malignant catatonia) can also be seen.
Most symptoms improve substantially in 6-12 treatments, however there is no absolute standard number of treatments. Some respond after only a few sessions and others require 20 or more. 2
Consider continuation or maintenance ECT. Continuation = provide one ECT treatment every one to eight weeks for the six months following remission. Maintenance = this is beyond continuation. Interval treatment given to those that require treatment to prevent recurrence of a new episode.
Treatment response should be serially monitored with depression rating scales.
Concurrent medications: many psychiatric meds may be continued during a course of ECT and may even have a synergistic effect without compromising safety. These include antidepressants, antipsychotics, and lithium. Anticonvulsants and Benzodiazepines can interfered with the ECT and may need to be tapered or discontinued.
ECT can safely be used for pregnant patients.
Side Effects
ECT is one of the safest procedures performed under general anesthesia.
Headaches: most common side effect that occurs after each treatment. Give acetaminophen or ibuprofen after treatment. May give prophylaxis IV ketorolac for those with significant ECT headaches.
Nausea: transient, common, result of the anesthesia and airway manipulation. Prophylaxis with IV ondansetron 4 mg should be given to patients with significant post-ECT nausea.
Memory loss: ECT can cause acute confusion, anterograde amnesia (decreased ability to retain newly acquired information), and retrograde amnesia (forgetting recent memories). These are typically the most feared side effects from patients. Many patients do experience some adverse cognitive effects, however objecting testing (MoCA, MMSE) indicates that impairment is generally short lived (weeks). ECT does not appear to be associated with an increased risk of dementia.
Rare: aspiration pneumonia, fracture (osteoporotic patients), dental/tongue injuries, myalgias.
CONCLUSION
Join use back for the next lesson where we discuss another interventional treatment for depression: transcranial magnetic stimulation (TMS). This is an up and coming treatment modality that everyone should learn more about.
Resources for this post include Kaplan and Sacock's Synopsis of Psychiatry, The Maudsley Prescribing Guidelines in Psychiatry and UpToDate.
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