Improvement of neuronal integrity with methylphenidate treatment for apathy in Alzheimer's disease

Treatment of Apathy in Parkinson's Disease and Implications for Underlying Pathophysiology

Apathy is a prevalent and highly debilitating non-motor symptom of Parkinson's disease (PD) that is often overlooked in clinical practice due to its subtle nature. This review aims to provide a comprehensive overview of the current evidence for the treatment of apathy in PD, highlighting recent advancements and emerging therapeutic avenues. In this review, we analyse a diverse array of treatment strategies for apathy in PD, including pharmacological interventions, non-pharmacological approaches, and emerging neuromodulation techniques. We evaluate the efficacy, safety, and limitations of established pharmacotherapies, such as dopaminergic agents, antidepressants, and cognitive enhancers. Additionally, we examine the promising role of non-pharmacological interventions, encompassing psychotherapies and behavioural interventions, in ameliorating apathetic symptoms. Furthermore, this review explores the effects of neuromodulation techniques on apathy, including the modulation of apathy via deep brain stimulation and emerging data on the potential influence of transcranial magnetic stimulation (TMS) on apathy in PD. Ultimately, a deeper understanding of effective treatment strategies for apathy has the potential to significantly improve the quality of life and overall well-being of individuals living with PD.

Effects of repetitive paired associative stimulation on brain plasticity and working memory in Alzheimer's disease: a pilot randomized double-blind-controlled trial

DESIGN

Pilot randomized double-blind-controlled trial of repetitive paired associative stimulation (rPAS), a paradigm that combines transcranial magnetic stimulation (TMS) of the dorsolateral prefrontal cortex (DLPFC) with peripheral median nerve stimulation.

OBJECTIVES

To study the impact of rPAS on DLPFC plasticity and working memory performance in Alzheimer's disease (AD).

METHODS

Thirty-two patients with AD (females = 16), mean (SD) age = 76.4 (6.3) years were randomized 1:1 to receive a 2-week (5 days/week) course of active or control rPAS. DLPFC plasticity was assessed using single session PAS combined with electroencephalography (EEG) at baseline and on days 1, 7, and 14 post-rPAS. Working memory and theta-gamma coupling were assessed at the same time points using the N-back task and EEG.

RESULTS

There were no significant differences between the active and control rPAS groups on DLPFC plasticity or working memory performance after the rPAS intervention. There were significant main effects of time on DLPFC plasticity, working memory, and theta-gamma coupling, only for the active rPAS group. Further, on post hoc within-group analyses done to generate hypotheses for future research, as compared to baseline, only the rPAS group improved on post-rPAS day 1 on all three indices. Finally, there was a positive correlation between working memory performance and theta-gamma coupling.

CONCLUSIONS

This study did not show a beneficial effect of rPAS for DLPFC plasticity or working memory in AD. However, post hoc analyses showed promising results favoring rPAS and supporting further research on this topic. (Clinicaltrials.gov-NCT01847586).

Efficacy of methylphenidate for the treatment of apathy in patients with Alzheimer's disease: a systematic review and meta-analysis of randomized controlled studies

RATIONALE

Despite the reported efficacy of methylphenidate (MET) against Alzheimer's disease (AD)-associated apathy, a recent larger clinical trial was not included in pooled analysis.

OBJECTIVES

This study aimed at investigating the efficacy of MET for attenuating apathy in patients diagnosed with AD.

METHODS

The PubMed, Cochrane Library, and EMBASE databases were searched from inception until March, 2022 to identify randomized controlled trials (RCTs). The primary outcome was apathy improvement assessed with the Neuropsychiatric Inventory (NPI) apathy subscale, Apathy Evaluation Scale (AES), or Clinical Global Impressions of Change scale (CGI-C apathy).

RESULTS

Meta-analysis of four RCTs revealed an improvement in apathy among patients receiving MET compared to placebo (MD =  - 5.12, p = 0.04, three trials, 144 participants) at follow-ups of 1-3 months assessed with AES score. Despite the absence of improvement on NPI-apathy subscale at follow-ups of 1-2 months (MD =  - 0.74, p = 0.37, three trials, 265 participants), significant improvement was noted at follow-ups of 6 months (MD =  - 1.4, p = 0.02, one trial, 180 participants). Assessment with CGI-C apathy revealed no significant association between improvement in apathy with MET use (RR = 1.38, p = 0.05, three trials, 265 participants). No significant differences in global cognitive function (using the Mini Mental State Exam) or adverse events were noted between the two groups.

CONCLUSION

While AES score suggested an early attenuation effect of MET on apathy in different domains, the NPI-apathy subscale did not show early improvement in apathy until the 6-month follow-up. Further studies with longer follow-ups are needed to elucidate the efficacy of MET for relieving caregiver burden and improving global functional performance.