Deep High-Frequency Repetitive Transcranial Magnetic Stimulation for Smoking Cessation (TMS)

Deep transcranial magnetic stimulation (TMS) is currently being evaluated as a treatment option in major depression. It has been shown to be a safe procedure . Deep transcranial magnetic stimulation coils are designed to maximize the electrical field deep in the brain by the summation of separate fields projected into the skull from several points around its periphery. The device is planned to minimize the accumulation of electrical charge on the surface of the brain. Such accumulation can give rise to an electrostatic field that might reduce the magnitude of the induced electric field both at the surface and inside, thus reducing the depth penetration of the induced electric field . Deep transcranial magnetic stimulation could be more effective than repetitive transcranial magnetic stimulation due to its deeper penetration into brain tissues . The deeper penetration should produce greater action on nerve fibers connecting the prefrontal cortex to the limbic system.

The ability of high-frequency repetitive transcranial magnetic stimulation (rTMS) to alter dopaminergic neurotransmission in subcortical structures could explain recent reports, which suggest that it has the potential to reduce smoking and nicotine craving. Ecihhammer et al demonstrated a reduction in the number of cigarettes smoked and in the desire to smoke after a single rTMS treatment (Eichhammer et al., 2003). In addition, Johan et al in a cross-over, double-blind, placebo-controlled study demonstrated a reduction in cigarette consumption and desire to smoke after a single repetitive transcranial magnetic stimulation treatment (Johann et al., 2003). Recently, the investigators have finished a complete study on nicotine addiction using repetitive transcranial magnetic stimulation for 10 consecutive days. They have found that 10 days of rTMS reduced significantly better from placebo the number of cigarettes smoked, nicotine dependence and craving (Amiaz et al 2007, in preparation). Interestingly, some of the effects were stronger in the sub-group of patients that were presented with smoking-related pictures immediately prior to stimulation onset. Although, these results are interesting and exciting, they have two important caveats. First, only about 50%-60% of the smokers responded to the repetitive transcranial magnetic stimulation treatment. Second, among those responded to the treatment, only 10% had quit totally from smoking. Therefore, the potential therapeutic benefit of this treatment is limited. The investigators' hypothesis is that deep transcranial magnetic stimulation may be more efficient in smoking cessation due to it's deeper penetration and therefore it's capability to stimulate deeper fibers of the dopamine-reward-activating system.