Parkinson’s Disease (PD) with mild cognitive impairment (MCI) (PD-MCI) represents one of the most dreaded complications for patients with PD and is associated with a higher risk of developing dementia. Although transcranial direct current stimulation (tDCS) has been demonstrated to improve motor and non-motor symptoms in PD, to date, no study has investigated the effects of tDCS on Theory of Mind (ToM), i.e., the ability to understand and predict other people’s behaviours, in PD-MCI. In this randomized, double-blind, sham-controlled study, we applied active tDCS over the medial frontal cortex (MFC) to modulate ToM performance in twenty patients with PD-MCI. Twenty matched healthy controls (HC) were also enrolled and were asked to perform the ToM task without receiving tDCS. In the patients with PD-MCI, i) ToM performance was worse than that in the HC, ii) ToM abilities were poorer in those with fronto-executive difficulties, and iii) tDCS over the MFC led to significant shortening of latency for ToM tasks. We show for the first time that active tDCS over the MFC enhances ToM in patients with PD-MCI, and suggest that non-invasive brain stimulation could be used to ameliorate ToM deficits observed in these patients.

Introduction: Given the limited effectiveness of pharmacological treatments, non-pharmacological interventions in neurodegenerative diseases have gained increasing attention in recent years and telerehabilitation has been proposed as a cognitive rehabilitation strategy. The purpose of this systematic review is to examine the evidence for the efficacy of cognitive telerehabilitation interventions compared with face-to-face rehabilitation in patients with mild cognitive impairment, Alzheimer’s disease and frontotemporal dementia. Methods: In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic search of the Medline database was conducted. Out of 14 articles assessed for eligibility, five studies were identified, three in participants with mild cognitive impairment or Alzheimer’s disease, two in patients with primary progressive aphasia. Results: The Physiotherapy Evidence Database scale was used to assess the methodological quality of four out of five studies included in this systematic review, with only one report receiving a high-quality rating. Effect-size analysis evidenced positive effects of telerehabilitation interventions, comparable with those reported for face-to-face rehabilitation. Discussion: The available evidence for the effectiveness of cognitive telerehabilitation is limited, and the quality of the evidence needs to be improved. The systematic review provides preliminary evidence suggesting that cognitive telerehabilitation for neurodegenerative disease may have comparable effects as conventional in-person cognitive rehabilitation.

Objectives: Episodic memory is impaired in amnestic mild cognitive impairment (aMCI), which is posited as a potential prodromal form of Alzheimer’s disease. Reactivated existing memories become sensitive to modification during reconsolidation. There is evidence that the lateral prefrontal cortex (PFC) plays causal role in episodic memory reconsolidation. Transcranial direct current stimulation (tDCS) applied to the PFC after a contextual reminder enhanced episodic memory performance up to 1 month, conceivably through reconsolidation, in older adults with subjective memory complaints, a condition that may represent a “pre-mild cognitive impairment” stage. The aim of this pilot study was to test the effect of PFC-tDCS (anode over left lateral PFC, cathode over right supraorbital area) after a contextual reminder on episodic memory in older adults with aMCI.Method: Older adults with aMCI learned a list of words. Twenty-four hours later, tDCS (Active or Sham) was applied after a contextual reminder. Memory retrieval (free recall and recognition) was tested 48 hrs and 1 month after the learning session.Results: Active tDCS enhanced recognition memory relative to Sham stimulation.Discussion: Modulating reconsolidation with PFC-tDCS might be a novel intervention to enhance episodic memories in aMCI.