Tai Chi May Delay Cognitive Decline in Older Persons with Dementia
November 26, 2012 -
This study, conducted by several universities in Hong Kong, examines the effects
of cognitive stimulation (mahjong) and physical exercise (tai chi [TC]) on
cognitive performance in persons with dementia.
Cluster-randomized open-label controlled design.
homes. PARTICIPANTS:: One hundred ten residents, most of whom were
cholinesterase-inhibitor naive. Inclusion criteria were Mini-Mental State
Examination (MMSE) = 10-24 and suffering from at least very mild dementia
(Clinical Dementia Rating >= 0.5). Exclusion criteria were being bedbound,
audio/visual impairment, regular activity participation before study, or
contraindications for physical or group activities.
Homes were randomized into three conditions (mahjong, TC, and simple handicrafts
[control]). Activities were conducted three times weekly for 12 weeks.
Primary outcome was MMSE. Secondary outcomes were immediate/delayed recall,
categorical fluency, and digit span. Various biological risk factors, including
apolipoprotein E [Latin Small Letter Open E]4 allele, were included as
covariates. Measures were collected at 0 (baseline), 3 (posttreatment), 6, and 9
Intent-to-treat analyses were performed using mixed-effects regression.
Mahjong's effect varied by time for MMSE, delayed recall, and forward digit
span. TC had similar effects but not for delayed recall. The typical pattern was
that control participants deteriorated while mahjong and TC participants
maintained their abilities over time, leading to enlarged treatment effects as
time progressed. By 9 months, mahjong and TC differed from control by 4.5 points
(95% confidence interval: 2.0-6.9; d = 0.48) and 3.7 points (95% confidence
interval: 1.4-6.0; d = 0.40), respectively, on MMSE. No treatment effects were
observed for immediate recall and backward digit span.
Mahjong and TC can preserve functioning or delay decline in certain cognitive
domains, even in those with significant cognitive impairment. This study is
published by Am J Geriatr Psychiatry in November 2012.