gms | German Medical Science

Objective: Atypical facial pain as a kind of neuropathic disorders could occur after traumatic lesions and remains difficult to treat. One option for management of intractable pain is stimulation of the motor cortex by implantation of an epidural electrode. This effect of invasive stimulation could be replaced by transcranial magnetic stimulation. The objective of the study was to observe the pain reducing effect of non-invasive transcranial magnetic stimulation (rTMS) in patients suffering from facial pain, and furthermore to detect whether there is a predictable value for invasive motor cortex stimulation (MCS).

Method: The study was prospective but not randomized. We included patients suffering from chronic neuropathic facial pain. The primary motor cortex has been stimulated with high-frequent, repetitive transcranial magnetic stimulation (rTMS). Stimulation was daily repeated for a period of 9 days. The individual pain level was assessed by the visual analogue scale (VAS) and documented daily for three weeks. The first follow-up was done after 6 weeks.

Results: We included 20 patients (14 female/ 6 male) between 32 and 75 years of age. The follow-up was done at least after six weeks, further intervals were determined individually with a maximum follow-up time of 2,5 years. 8 patients suffered from posttraumatic pain, 12 patients suffered from idiopathic atypical facial pain. A pain reduction in terms of a decrease in the VAS was obtained in 14 patients, ranging from 2 to 8 points of decrease with a mean value of 5,0. The pain reduction occurred with a delay between 3 and 28 days (mean 16 days), and showed a long-term effect up to 6 weeks. Two patients successfully underwent invasive motor cortex stimulation.

Conclusions: Non invasive transcranial magnetic stimulation seems to be applicable for some kind of neuropathic pain, i.e. atypical facial pain. Pain reduction has a long-term effect. Furthermore, it may be used as a positive predictor for invasive motor cortex stimulation.