Protection against Brain Atrophy by Anti-dementia Medication in Mild Cognitive Impairment and Alzheimer's Disease: Meta-Analysis of Longitudinal Randomized Placebo-Controlled Trials.

Abstract

BACKGROUND:

There has not been conclusive evidence for prevention of brain atrophy by anti-dementia drugs in mild cognitive impairment and Alzheimer's Disease.

METHODS:

Relevant studies were identified through searches of PubMed, databases of the Cochrane Library, and PsycINFO citations up to 16 May, 2015. Only double-blind, randomized, placebo-controlled clinical trials of anti-dementia drugs in patients with mild cognitive impairment or Alzheimer's Disease were included. Primary outcomes were annualized percent change of total brain volume (%TBV/y), annualized percent change of hippocampal volume (%HV/y), and annualized percent change of ventricular volume (%VV/y) measured by magnetic resonance imaging. Standardized mean difference (SMD) and 95% confidence intervals (CI) were calculated for relevant outcomes.

RESULTS:

Seven randomized, placebo-controlled clinical trials (n=1708) were found to meet the inclusion criteria, including 4 mild cognitive impairment studies (n=1327) and 3 Alzheimer's Disease studies (n=381) [3 donepezil studies (2 mild cognitive impairment studies and 1 Alzheimer's Disease study), 1 galantaime study for mild cognitive impairment, 2 mementine studies for Alzheimer's Disease, and 1 rivastigmine study for mild cognitive impairment]. Pooled anti-dementia drugs showed superior protective outcomes compared with placebo regarding %TBV/y (SMD=-0.21, 95%CI=-0.37 to -0.04, P=.01, N=4, n=624) and %VV/y (SMD=-0.79, 95%CI=-1.40 to -0.19, P=.01, N=3, n=851). However, %HV/y failed to show difference between both groups. Among anti-dementia drugs, donepezil showed significantly greater protective effects than placebo regarding %TBV/y (SMD=-0.43, 95%CI=-0.74 to -0.12, P=.007, N=1, n=164) and %VV/y (SMD=-0.51, 95%CI=-0.73 to -0.29, P<.00001, N=2, n=338). Rivastigmine was also superior to placebo regarding %VV/y (SMD=-1.33, 95%CI=-1.52 to -1.14, P<.00001).

CONCLUSIONS:

The results favored the hypothesis that anti-dementia drugs may prevent brain atrophy in patients with mild cognitive impairment and Alzheimer's Disease.

• Authors: Taro Kishi, Shinji Matsunaga, Kazuto Oya, Toshikazu Ikuta, Nakao Iwata
• Journal: The international journal of neuropsychopharmacology (Int J Neuropsychopharmacol) Vol. 18 Issue 12 (Jun 19 2015) ISSN: 1469-5111 [Electronic] England
• PMID: 26091818 (Publication Type: Journal Article, Meta-Analysis)
• Copyright: © The Author 2015. Published by Oxford University Press on behalf of CINP.

Chemical References

• Neuroprotective Agents
• Nootropic Agents

Topics

• Alzheimer Disease (drug therapy, pathology)
• Atrophy (drug therapy)
• Brain (drug effects, pathology)
• Cognitive Dysfunction (drug therapy, pathology)
• Humans
• Neuroprotective Agents (therapeutic use)
• Nootropic Agents (therapeutic use)
• Randomized Controlled Trials as Topic