The Efficacy and Safety of Pharmacological Treatments for Post-stroke Aphasia.

BACKGROUND: Aphasia is a common complication after stroke, and traditional speech and language therapy (SLT) has a limited effect on post-stroke aphasia (PSA). While there has been an increasing number of controlled clinical trials on the efficacy of drugs in the treatment of PSA, there have been very few systematic reviews on the efficacy and safety of pharmacological treatments in people with PSA. OBJECTIVE: To evaluate the efficacy and safety of pharmacological interventions for PSA. METHODS: The Cochrane Central Register of Controlled Trials (CENTRA), PubMed, Embase, Chinese Journal Full-text Database (CJFD), China Biology Medicine disc (CBMdisc), Wanfang Data and VIP Information System were searched for randomized controlled trials about pharmacological treatments for PSA. Literature screening using the inclusion and exclusion criteria, data extraction and methodological quality assessment of the included studies were completed by two independent reviewers. Methodological quality was considered high for modified Jadad quality scale scores of 4 to 7. RevMan 5.3 software was used to conduct a meta-analysis of high-quality studies. RESULTS: Fifteen studies (578 participants) satisfied the eligibility criteria for this systematic review. Five trials (277 participants) assessed donepezil, four studies (124 participants) assessed memantine, three studies (72 participants) assessed bromocriptine, one trial (45 patients) evaluated galantamine, one study (21 patients) evaluated amphetamine, and one trial (39 patients) evaluated levodopa. The systematic review showed that donepezil achieved remarkable results in terms of the aphasia quotient (AQ) (SMD 0.82, 95% CI 0.48-1.17, P < 0.00001), repetition ability (SMD 0. 81, 95% CI 0.57-1.06, P < 0.00001), naming ability (SMD 0.56, 95% CI 0.29-0. 84, P < 0.00001), auditory comprehension (SMD 0.85, 95% CI 0.58-1. 13, P< 0.00001) and oral expression (SMD 0.90, 95% CI 0.54-1.26, P < 0.00001). Memantine showed no pronounced improvement in auditory comprehension (SMD 0.35, 95% CI -0.05-0.74, P = 0.09) but did improve the AQ (SMD 0.57, 95% CI 0.09-1.06, P = 0. 02), naming ability (SMD 0.81, 95% CI 0.38-1.25, P = 0.0002), spontaneous speech (SMD 0.76, 95% CI 0. 39- 1.13, P < 0.0001), and repetition ability (SMD 0.37, 95% CI 0.01-0.73, P = 0.04). Bromocriptine showed pronounced improvement in naming ability (SMD -0.20, 95% CI- 0.67-0.26, P = 0.39), verbal fluency (SMD 0.02, 95% CI 0.53-0.56, P = 0.95), and repetition ability (SMD 0.29, 95% CI -0.23-0. 81, P = 0.28). There is limited and inconclusive evidence for galantamine, amphetamine and levodopa. CONCLUSION: Current evidence suggests that drugs, such as donepezil and memantine, can improve the prognosis of PSA. Donepezil has a significant effect in improving the ability of auditory comprehension, naming, repetition and oral expression. Memantine has a significant effect in improving the ability of naming, spontaneous speech and repetition. Bromocriptine showed no significant improvements in the treatment of aphasia after stroke. Data regarding galantamine, amphetamine and levodopa in the treatment of aphasia after stroke are limited and inconclusive.

MicroRNA-107 prevents amyloid-ß-induced neurotoxicity and memory impairment in mice.

The pathogenesis of Alzheimer's disease (AD) has still not been fully elucidated, however it is thought that the build up of amyloid plaque at least partially causes the symptoms of AD. MicroRNAs (miRNAs) are endogenous non­coding small RNA molecules that regulate the expression and degradation of proteins. The present study induced symptoms of AD in mice via intraventricular injection of amyloid­ß 1­42 (Aß1­42), which decreased levels of miR­107. However, miR­107 levels increased following administration of miR­107 mimic, a double­stranded RNA molecule designed to imitate the native miRNA. Intraventricular injection of Aß1­42 aggregates led to spatial memory impairments, inhibited hippocampal long­term potentiation (LTP) and resulted in the loss of pyramidal cells in the CA1 region of the hippocampus. The miR­107 mimic reversed the impairments of spatial memory and LTP and the loss of pyramidal neurons caused by Aß neurotoxicity. Furthermore, the miR­107 mimic reversed the Aß­induced increase in Aß1­42 and phosphorylated Tau levels. Critically, Aß1­42 injection decreased levels of brain­derived neurotrophic factor and reduced the phosphorylation of tyrosine receptor kinase B and protein kinase B; these changes were reversed following treatment with the miR­107 mimic. Collectively, these results demonstrated that miR­107 may be a potential target for the treatment of AD.