Durant les 15 dernières années, les effets thérapeutiques de la stimulation magnétique transcrânienne (SMTr) ont été étudiés dans les pathologies psychiatriques, notamment la dépression. Chez les patients âgés, des données de plus en plus nombreuses suggèrent une efficacité dans le traitement des dépressions. C’est pourquoi les auteurs proposent une revue des études sur l’efficacité et la tolérance de la SMTr dans les dépressions chez le sujet âgé. Leur travail repose sur une consultation exhaustive des bases de données bibliographiques complétées par une recherche manuelle. Quinze études ont été retenues, la plupart utilisant la SMTr haute fréquence au niveau du cortex dorsolatéral préfrontal gauche. Bien que les résultats ne soient pas tous convergents, de plus en plus de données de la littérature sont en faveur d’une efficacité de la SMTr dans les dépressions du sujet âgé. Plusieurs paramètres paraissent être associés à une plus grande efficacité (intensité de la stimulation, nombre de stimulations et de sessions de SMTr) tandis que sont de mieux en mieux identifiés les facteurs (notamment âge plus élevé, lésions ischémiques cérébrales…) associés à une moindre réponse au traitement. Des questions demeurent concernant notamment les paramètres techniques d’administration des protocoles et les indications, questions qui justifient que des études soient spécifiquement menées pour y répondre.

During the past 15 years, therapeutic effects of repetitive Transcranial Magnetic Stimulation (rTMS) have been studied in psychiatric diseases, particularly in the treatment of depressive disorders. There are more and more data suggesting its efficacy in the treatment of depression in older patients. Thus, the authors found it useful to conduct an up-to-date review of studies that examined the efficacy and safety of rTMS to treat depressive disorders in the aged.

After an exhaustive consultation of databases (Medline/PubMed and the Avery-George-Holtzheimer Database of rTMS Depression Studies), supplemented by a manual research, the authors retained studies evaluating the therapeutic efficacy of rTMS on depressive disorders in the aged.

Fifteen studies were retained. Four open studies using high frequency rTMS, applied to the left dorsolateral prefrontal cortex (DLPFC), demonstrated a decrease in the mean Hamilton Depression Rating Scale (HDRS) scores; however, only a quarter of the aged patients studied experienced a significant remission of depression. Five parallel arm double-blind versus placebo studies concluded in contradicting results: two studies confirmed a significantly greater efficacy of rTMS compared to placebo, whereas three studies did not; but the sham procedure (positioning coil at 90° from the scalp) was disputable in most studies. One study concluded in therapeutic efficacy by inhibiting the right DLPFC. Three controlled parallel arm studies compared rTMS and electroconvulsivo-therapy (ECT); one study concluded in greater efficacy of ECT at end of treatment, but the number of ECT treatments depended on the patients’ response, whereas a 15-day course of rTMS was systematically administered; additionally HDRS scores were similar in two groups of patients (rTMS and ECT) at 6 months. Lastly, three studies focused on aged patients with cerebrovascular disease. They showed the efficacy of rTMS, although older age and smaller frontal gray mater volumes were associated with a poorer response to rTMS.

Thus, although some studies concluded contradicting results, literature data globally sustain an efficacy of rTMS for depression in the elderly. Several parameters might be associated with greater antidepressant efficacy (higher intensity pulses of rTMS of the left DLPFC; higher number of stimulations or higher number of rTMS sessions). Poorer responsiveness to rTMS may be related to several patients’ factors including older age and smaller frontal gray matter volumes; lesions of the white matter pathways connecting the left DLPFC and the left anterior cingulate cortex might explain a poor response to rTMS. Literature data globally confirm that rTMS is safe and does not produce cognitive deficits, even among highly vulnerable patients with clinical evidence of cerebrovascular disease.

Many questions remain concerning the optimal stimulation parameters, administration protocol, and privileged indications. Thus, the next rTMS studies should be carefully designed to clarify these questions.