Language impairment in Alzheimer’s disease and benefits of acetylcholinesterase inhibitors

Abstract

Alzheimer’s disease is characterized by progressively worsening deficits in several cognitive domains, including language. Language impairment in Alzheimer’s disease primarily occurs because of decline in semantic and pragmatic levels of language processing. Given the centrality of language to cognitive function, a number of language-specific scales have been developed to assess language deficits throughout progression of the disease and to evaluate the effects of pharmacotherapy on language function. Trials of acetylcholinesterase inhibitors, used for the treatment of clinical symptoms of Alzheimer’s disease, have generally focused on overall cognitive effects. However, in the current report, we review data indicating specific beneficial effects of acetylcholinesterase inhibitors on language abilities in patients with Alzheimer’s disease, with a particular focus on outcomes among patients in the moderate and severe disease stages, during which communication is at risk and preservation is particularly important.

Keywords:

• Alzheimer’s disease
• donepezil
• cognition
• language
• communication
• clinical trials

Acknowledgments

Editorial support in the development of this manuscript was provided by R Daniel and K Ayling-Rouse of Parexel, and was funded by Eisai Inc and Pfizer Inc.

Disclosure

SHF has served as a paid scientific consultant to Accera, Baxter, Bristol-Myers Squibb, Eisai, Elan, Eli Lilly, Janssen AI, MedAvante, Merck, Merz, Neuronix, Novartis, Otsuka, Pfizer, Toyama, and United BioSource. His institution has received grant/contract support for clinical trials from Baxter, Bristol-Myers Squibb, Eisai, Eli Lilly, Janssen AI, Merck, Neuronix, Pfizer, Roche, and Takeda. He also has stock options from Accera, Intellect Neurosciences, MedAvante and Raptor, and owns stock in Lexicon.

MF has served as a paid consultant for Accera, Alltech, Astellas, Bayer, Bristol-Myers Squibb, Eisai Medical Research, GE Healthcare, Helicon, MedAvante, Mediation, Inc., Merck and Co, Inc., Novartis Pharma, Pfizer, Prana Biotech, QR Pharma, Sanofi-aventis Groupe, Schering-Plough, Lilly, Shire Pharmaceuticals, and Toyama, is a paid speaker for Eisai, Forest, Novartis, and Pfizer, and receives research support from Eisai, Eli Lilly and Co, Genentech, Novartis Pharm, and Roche.