Repetitive transcranial magnetic stimulation (rTMS) for simultaneous treatment of comorbid somatic and psychiatric disorders

Repetitive transcranial magnetic stimulation (rTMS) is efficient in several neuropsychiatric conditions such as major depression and neuropathic pain that may co-exist in individual patients. Genetic factors seem to be crucially involved in the treatment response that is variable between subjects. The aim of the present study was to investigate efficacy of rTMS in patients treated for more than one indication with rTMS, testing hypothesis that treatment response is determined by constitutional within-subject factors more than by clinical diagnosis and thus, the patient would either benefit from the treatment in both conditions or not at all. We analyzed 33 clinical patients (20 women; median age 49 years, range 17 – 75 years) who had undergone serial rTMS treatment for 1) pain and depression (N=15), 2) depression and anxiety (N=7), 3) depression and tinnitus (N=6), and 4) other combinations (N=5). E-field navigated TMS device (Nexstim Ltd, Finland) was used for 10-day serial treatment. Frequency of stimulation (1 Hz or 10 Hz) and cortical targets varied according to indication. Two patients dropped out at the beginning because of worsening of symptoms. 30 % decrease in symptom severity on disorder specific scales was considered a response. Global Impression of Change (GIC; -3…+3) was available for 20 patients. 31 patients with enough follow-up data were analyzed: 23 benefitted in more than one indication, 4 benefitted in one only, and 4 did not get benefit in any indication. Thus, 87 % of the patients either benefitted in both treatment indications or did not benefit at all. On GIC, 80 % of patients reported positive change, 20% did not report any change (0). Efficacy did not depend on age or sex.