[Therapeutic efficacy and safety of repetitive Transcranial Magnetic Stimulation in depressions of the elderly: a review].
BACKGROUND
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.


METHODS
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.


RESULTS
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 degrees 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 electroconvulsive-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.


CONCLUSIONS
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.


CONCLUSIONS
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.
Service de psychiatrie de l'adulte A et psychologie médicale, pôle de psychiatrie, CHU de Clermont-Ferrand, BP 69, 63003 Clermont-Ferrand cedex 1, France. ijalenques@chu-clermontferrand.fr
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Jalenques
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Legrand
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Vaille-Perret
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Tourtauchaux
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Galland
D000368:Aged; D000369:Aged, 80 and over; D018849:Controlled Clinical Trials as Topic; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology / Q000628:therapy*; D004292:Dominance, Cerebral / Q000502:physiology; D004311:Double-Blind Method; D004565:Electroconvulsive Therapy; D005500:Follow-Up Studies; D006801:Humans; D010555:Personality Inventory; D017397:Prefrontal Cortex / Q000503:physiopathology; D050781:Transcranial Magnetic Stimulation; D016896:Treatment Outcome