45.2 Brain Stimulation

45-2 How are brain stimulation and psychosurgery used in treating specific disorders?

Electroconvulsive Therapy

electroconvulsive therapy (ECT) a biomedical therapy for severely depressed patients in which a brief electric current is sent through the brain of an anesthetized patient.

Another biomedical treatment, electroconvulsive therapy (ECT), manipulates the brain by shocking it. When ECT was first introduced in 1938, the wide-awake patient was strapped to a table and jolted with roughly 100 volts of electricity to the brain. The procedure, which produced racking convulsions and brief unconsciousness, gained a barbaric image. Although that image lingers, today’s ECT is much kinder and gentler. The patient receives a general anesthetic and a muscle relaxant to prevent convulsions. A psychiatrist then delivers to the patient’s brain 30 to 60 seconds of electric current in briefer pulses, sometimes only to the brain’s right side (FIGURE 45.2). Within 30 minutes, the patient awakens and remembers nothing of the treatment or of the preceding hours.

The medical use of electricity is an ancient practice. Physicians treated the Roman Emperor Claudius (10 B.C.E.–54 C.E.) for headaches by pressing electric eels to his temples.

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Figure 15.6: FIGURE 45.2 Electroconvulsive therapy Although controversial, ECT is often an effective treatment for depression that does not respond to drug therapy. (“Electroconvulsive” is no longer accurate, because patients are now given a drug that prevents bodily convulsions.)

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Study after study confirms that ECT can effectively treat severe depression in “treatment-resistant” patients who have not responded to drug therapy (Bailine et al., 2010; Fink, 2009; Lima et al., 2013). After three such sessions each week for two to four weeks, 80 percent or more of those receiving ECT improve markedly. They show some memory loss for the treatment period but no apparent brain damage. Modern ECT causes less memory disruption than earlier versions did (HMHL, 2007). ECT also reduces suicidal thoughts and has been credited with saving many from suicide (Kellner et al., 2005). A Journal of the American Medical Association editorial concluded that “the results of ECT in treating severe depression are among the most positive treatment effects in all of medicine” (Glass, 2001).

“I used to … be unable to shake the dread even when I was feeling good, because I knew the bad feelings would return. ECT has wiped away that foreboding. It has given me a sense of control, of hope.”

Kitty Dukakis (2006)

How does ECT relieve severe depression? After more than 70 years, no one knows for sure. One patient likened ECT to the smallpox vaccine, which was saving lives before we knew how it worked. Perhaps the brief electric current calms neural centers where overactivity produces depression. Some research indicates that ECT works by weakening connections in a “hyperconnected” neural hub in the left frontal lobe (Perrin et al., 2012).

No matter how impressive the results, the idea of electrically shocking people still strikes many as barbaric, especially given our ignorance about why ECT works. Moreover, about 4 in 10 people treated with ECT relapse into depression within six months (Kellner et al., 2006). Nevertheless, in the minds of many psychiatrists and patients, ECT is a lesser evil than severe depression’s misery, anguish, and risk of suicide. As research psychologist Norman Endler (1982) reported after ECT alleviated his deep depression, “A miracle had happened in two weeks.”

Alternative Neurostimulation Therapies

Two other neural stimulation techniques—magnetic stimulation and deep brain stimulation—also treat the depressed brain.

repetitive transcranial magnetic stimulation (rTMS) the application of repeated pulses of magnetic energy to the brain; used to stimulate or suppress brain activity.

MAGNETIC STIMULATION Depressed moods sometimes improve when repeated pulses surge through a magnetic coil held close to a person’s skull (FIGURE 45.3). The painless procedure—called repetitive transcranial magnetic stimulation (rTMS)—is performed on wide-awake patients over several weeks. Unlike ECT, the rTMS procedure produces no brain seizures, memory loss, or other serious side effects aside from possible headaches.

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Figure 15.7: FIGURE 45.3 Magnets for the mind Repetitive transcranial magnetic stimulation (rTMS) sends a painless magnetic field through the skull to the surface of the cortex. Pulses can be used to alter activity in various cortical areas.
Jaroslaw Wojcik/iStock/360/Getty Images

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Initial studies have found a small antidepressant benefit of rTMS (Lepping et al., 2014). How it works is unclear. One possible explanation is that the stimulation energizes the brain’s left frontal lobe (Helmuth, 2001). Repeated stimulation may cause nerve cells to form new functioning circuits through the process of long-term potentiation.

A meta-analysis of 17 clinical experiments found that one other stimulation procedure alleviates depression: massage therapy (Hou et al., 2010).

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A depression switch? By comparing the brains of patients with and without depression, researcher Helen Mayberg identified a brain area (highlighted in red) that appears active in people who are depressed or sad, and whose activity may be calmed by deep brain stimulation.
Helen Mayberg, M.D. Psychiatric Neuroimaging and Therapeutics, The Mayberg Lab at Emory University, Atlanta, GA/V. J. Wedeen and L. L. Wald/Athinoula A. Martinos Center For Biomedical Imaging and The Human Connectome Project, Boston, MA

DEEP BRAIN STIMULATION Other patients whose depression has resisted both drugs that flood the body and ECT that jolts at least half the brain have benefited from an experimental treatment pinpointing a brain depression center. Neuroscientist Helen Mayberg and her colleagues (2005, 2006, 2007, 2009) have been focusing on a neural hub that bridges the thinking frontal lobes to the limbic system. This area, which is overactive in the brain of a depressed or temporarily sad person, calms when treated by ECT or antidepressants. To experimentally excite neurons that inhibit this negative emotion-feeding activity, Mayberg drew upon the deep brain stimulation technology sometimes used to treat Parkinson’s tremors. Since 2003, she and others have treated some 200 depressed patients with deep brain stimulation via implanted electrodes in the neural “sadness center” (Lozano & Mayberg, 2015). About one-third reportedly have responded “extremely well” and another 30 percent have modestly improved (Underwood, 2013). Some felt suddenly more aware and became more talkative and engaged; others improved only slightly, if at all. Future research will explore whether Mayberg has discovered a switch that can lift depression. Other researchers are following up on reports that deep brain stimulation can offer relief to people with obsessive-compulsive disorder and with drug and alcohol addictions (Corse et al., 2013; Kisely et al., 2014; Luigjes et al., 2012).

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Question

Severe depression that has not responded to other therapy may be treated with s9DUHrUkUBu8aKcaYd0sqip+8KO8qLD/p/tJTMVc9leutrMu , which can cause brain seizures and memory loss. More moderate neural stimulation techniques designed to help alleviate depression include lJ7FCvIUe27eFMGqmTWA1z+NxPX9kj8Lw8N2GQ== magnetic stimulation and qQ71QyCWirS3d//T51pDSfU0+9VmCfj6B9wZSg== stimulation.