Intérêt de la TMS au long cours au sein d’une population de patients âgés déprimés résistants

Repetitive transcranial magnetic stimulation treatment (rTMS) in elderly depressed subjects (>60 years) should be assessed in view of the absence of severe side effects. But most of the results in the literature were negative probably due to too short a duration of TMS treatment in this particular population. In this article, the authors report the results of an open study over a 6-month period: 1 month of curative treatment followed by an average of 5 months of maintenance sessions. Twelve refractory elderly depressed patients were included (five men and seven women, nine unipolar and three bipolar according to the DMS-IV criteria), aged between 60 and 78 years (70 ± 6.24) and no responders to at least two different antidepressants over 6 weeks. The average duration of depressive disease was 10.88 years (10.13) with an average of 3.82 (3.28) number of hospitalizations. All patients provided informed consent. During the first period, patients received a daily session of rTMS, 5 days a week for the first and second week then three sessions a week for the third and fourth week. The stimulation was performed on the left dorsolateral prefrontal cortex (10 Hz, 80 % of the motor threshold, 26 trains of 6 s with an interval of 30 s). In the second period, patients received one weekly session during the second month (M2), then one rTMS session each fortnight the following months. The Hamilton depression rating scale (17 items) was used to assess the intensity of depressive symptoms. Clinical ratings were assessed at baseline, each week during the first month and monthly for 5 months (M6). The authors used a 50 % reduction criteria in Hamilton Depression Rating Scale (HDRS) scores following treatment compared to baseline for responders, and HDRS <8 for patients in remission. The results show a significant drop in HDRS scores after 1 month of rTMS: at baseline 22.50 ± 2.84 versus at M1 10.25 ± 4.18, p < 0.001. Two no responders received only 1 month of rTMS treatment. The other responder patients (n = 10) had the possibility of receiving the treatment by rTMS maintenance for 5 months. The HDRS score showed no difference between the mean HDRS score at M1 and M6 (p > 0.05). We noted a high score in compliance to the TMS treatment in this sample: 75 % (n = 9) at M6 with only three drop-outs. No side effect was reported, except headache. The absence of cognitive effects is a strong argument in favor of TMS use in this population. Nevertheless, new double blind studies are needed to confirm this therapeutic tool and the benefits of rTMS in the treatment of elderly resistant depressed people.