The vagus nerve runs from neck to chest and abdomen. Additional fibers connect from the vagus nerve to brain. Stimulation of the VNS alters the susceptibility of the brain to have seizures (13). Several scientific studies, the results of which have been accepted by the US Food and Drug Administration, show a reduction of seizures when the vagus is stimulated electrically. Electrical stimulation is done via a battery-powered metal stimulator implanted under the skin of the chest. Wires connect under the skin to the left vagus nerve, and deliver stimulation on a programmable cycle, typically 30 seconds of stimulation followed by 5 minutes of rest. After a few months of VNS, seizures can begin to diminish. By a year after start of stimulation, seizures tend to be reduced by about half. Some people obtain greater benefit and others none at all; unfortunately, this is hard to predict in advance of trying the stimulation. Complete elimination of seizures by VNS is unusual. Side effects of VNS are usually mild, including hoarseness and coughing, mostly while becoming use to the stimulation. VNS also is approved by the FDA for depression that does not respond to other treatments.

Read more about the VNS here on epilepsy.com.

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Topic Editor: Robert S. Fisher, MD, PhD
Last Reviewed: April 21, 2009