Transcranial Magnetic Stimulation to Address Mild Cognitive Impairment in the Elderly: A Randomized Controlled Study

Abstract

Transcranial magnetic stimulation (TMS) is a noninvasive brain stimulation technique with potential to improve memory. Mild cognitive impairment (MCI), which still lacks a specific therapy, is a clinical syndrome associated with increased risk of dementia. This study aims to assess the effects of high-frequency repetitive TMS (HF rTMS) on everyday memory of the elderly with MCI. We conducted a double-blinded randomized sham-controlled trial using rTMS over the left dorsolateral prefrontal cortex (DLPFC). Thirty-four elderly outpatients meeting Petersen's MCI criteria were randomly assigned to receive 10 sessions of either active TMS or sham, 10 Hz rTMS at 110% of motor threshold, 2,000 pulses per session. Neuropsychological assessment at baseline, after the last session (10th) and at one-month follow-up, was applied. ANOVA on the primary efficacy measure, the Rivermead Behavioural Memory Test, revealed a significant group-by-time interaction (p = 0.05), favoring the active group. The improvement was kept after one month. Other neuropsychological tests were heterogeneous. rTMS at 10 Hz enhanced everyday memory in elderly with MCI after 10 sessions. These findings suggest that rTMS might be effective as a therapy for MCI and probably a tool to delay deterioration.

Effects of repetitive transcranial magnetic stimulation on improvement of cognition in elderly patients with cognitive impairment: a systematic review and meta‐analysis

“…Coppi et al () and Ash et al () reported using the fronto‐parietal–temporal lobes and prefrontal areas, respectively, without specifying the exact target site. Regarding the targeting method, six studies used magnetic resonance imaging‐guided navigation (Cotelli et al , ; Cotelli et al , ; Turriziani et al , ; Rabey et al , ; Anderkova et al , ; Lee et al , ) and three studies used a non‐imaging‐based technique (Ahmed et al , ; Drumond Marra et al , ; Rutherford et al , ), either a 5‐cm rule to locate the DLPFC (Pascual‐Leone et al , ) or an electroencephalography 10–20 system to locate the brain area.…”

“…Four studies reported adverse effects of rTMS, including headache, cervical and scalp pain, burning scalp and non‐specific minor discomfort (Anderkova et al , ; Drumond Marra et al , ; Rutherford et al , ; Wu et al , ). Wu et al () reported one participant with mild extrapyramidal reactions.…”

“…Trials with concurrent cognition‐enhancing drugs (Cotelli et al , ; Brem et al , ; Rabey et al , ; Lee et al , ) showed no significant improvement in cognition after active rTMS (SMD = 0.66, 95% CI −0.21 to 1.53). A significant rTMS effect was found amongst those without cognition‐enhancing drugs (Ahmed et al , ; Drumond Marra et al , ; Wu et al , ) (SMD = 0.44, 95% CI 0.08 to 0.80) (Figure ).…”

“…No significant rTMS effect was reported amongst trials with concurrent cognitive training (Brem et al , ; Rabey et al , ; Lee et al , ) (SMD = 0.94, 95% CI −0.09 to 1.97). Trials without cognitive training (Cotelli et al , ; Ahmed et al , ; Drumond Marra et al , ; Wu et al , ) showed improvement in cognition after active rTMS (SMD = 0.39, 95% CI 0.05 to 0.73) (Figure ).…”

Non-Invasive Brain Stimulation in Dementia: A Complex Network Story

“…Their findings showed that a single session over the DLPFC was sufficient to strengthen episodic memory up to 1 month, relative to sham stimulation [95]. Similarly, DLPFC modulation showed beneficial memory effects in mild cognitive impairment (MCI) patients [97, 98], although these positive effects were obtained using different stimulation protocols (i.e., 10 excitatory sessions vs. 1 inhibitory session). In a sham-controlled study, Meinzer et al [96] demonstrated that atDCS improved language performance in MCI patients after IFG stimulation.…”