Bipolar Vs. Unipolar Electrode Placement
Electroconvulsive therapy, or ECT, can be an effective treatment for depression when medications and therapy have failed. However, memory loss is a common side effect, with some patients reporting no recollection of months or years of their lives. One factor that can affect the degree of memory loss is the placement of seizure-inducing electrodes on the patient's scalp. When considering ECT, it is important to educate yourself about the differences between unipolar and bipolar electrode placement.
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Disorders That can be Successfully Treated Using ECT
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ECT has proven effective in the treatment of bipolar disorder, schizophrenia and obsessive-compulsive disorder, but its most common indication today is treatment-resistant depression. "Treatment-resistant" refers to depression which has proven unresponsive to traditional talk therapy and antidepressant medication. ECT may also be used as a first-line treatment in severe depression with suicidal ideation or the presence of psychosis. Suicidal patients have seen remittance of symptoms in as little as a single ECT session.
Unipolar Electrode Placement
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"Unipolar" means that electrodes are placed on only the patient's right temple before the electrical seizure is induced. While unipolar ECT is effective in curbing memory loss, it has proven less effective in treating depression. One way of administering unipolar ECT for maximum treatment efficacy is by increasing the electrical stimulus traveling through the single electrode. Unipolar treatment is sometimes administered at up to six times the seizure threshold, or amount of electricity required to induce an electrical seizure.
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Bipolar Electrode Placement
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Bipolar placement, found to be more effective in treating depression, although more likely to induce memory loss, is the default for ECT in the United States and United Kingdom. There are two types of bilaterial placement: bifrontal and bitemporal. In bifrontal placement, electrodes are positioned on the front of the forehead. In bitemporal, they are placed on the temples. Bilateral ECT requires six times less energy than unilateral to effect the same results, leading scientists to question the decrease in cognitive deficit of unipolar therapy.
Induction of Seizure
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ECT works by inducing a seizure lasting at least 15 seconds. While many people think of the thrashing, grimacing "shock therapy" scenes from decades-old movies, modern ECT is done under general anesthesia with the use of muscle relaxants. The patient is completely unconscious during the treatment. While some physicians may administer "fixed-dose" ECT, using the same electrical stimulus for all patients, many titrate the dosage of electricity based on the subject's height, weight and age. You should always ask your physician which method he uses.
Bipolar or Unipolar
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Ultimately, the consumer must discuss the relative merits of bipolar and unipolar ECT with her physician to make the best decision for personalized treatment. In cases of severe suicidal depression, bipolar ECT may provide more rapid relief, and the increased risk of memory deficit may seem worth it in the face of saving one's own life. Whether you ultimately choose high-voltage unipolar or lower-voltage bipolar is dependent upon your individual symptoms and desired treatment outcome.
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