乌鸦传媒

Repetitive transcranial magnetic stimulation (rTMS) added to tai chi chuan exercise improved sleep and cognition in older adults who had both sleep disorders and mild cognitive impairment, a randomized clinical trial showed.

Six weeks after the intervention, the group that received rTMS and tai chi had better Pittsburgh Sleep Quality Index (PSQI) scores than those who received sham stimulation and tai chi (mean difference -3.1 points, 95% CI -4.2 to -2.1, P<0.001), according to Jing Tao, MD, PhD, of the Fujian University of Traditional Chinese Medicine in Fuzhou, China, and co-authors. The PSQI ranges from 0 to 21, with lower scores indicating healthier sleep quality.

The rTMS group also had higher global cognitive function assessed by Montreal Cognitive Assessment (MoCA) scores at 6 weeks, with a between-group mean difference of 1.4 points (95% CI 0.7-2.1, P<0.001). The MoCA ranges from 0 to 30, with higher scores indicating better performance.

At 12 weeks, differences in PSQI (mean difference -2.1, 95% CI -3.1 to -0.1, P<0.001) and MoCA (mean difference 0.9, 95% CI 0.1-1.6, P=0.01) scores were still evident, Tao and colleagues reported in.

Sleep disorders and cognitive impairment commonly co-exist in older adults. "Findings suggest that 1-Hz rTMS enhanced the clinical benefits of tai chi chuan in improving sleep quality and cognitive function among older adults with sleep disorders and mild cognitive impairment, which may be related to alterations in neural plasticity," Tao and co-authors wrote.

"These findings provide novel data on nonpharmacologic strategies for the rehabilitation of sleep disorders and may delay or even prevent mild cognitive impairment," they added.

Pharmacologic treatment is often used as a first-line option for sleep and cognitive disorders but it has limitations, including adverse effects or diminishing efficacy over time, noted Giuseppe Lanza, MD, PhD, of the Oasi Research Institute IRCCS in Troina, Italy, and colleagues, in an .

"Among other treatment options, noninvasive brain stimulation (e.g., rTMS) and holistic therapies (e.g., tai chi chuan) have gained increasing attention as promising alternatives," they wrote.

The theory, long established in insomnia, suggests that increased electroencephalographic high-frequency activity during sleep, taken to indicate cortical hyperarousal, persists during wakefulness, Lanza and co-authors said. A similar pattern of cortical hyperexcitability is seen in Alzheimer's disease, including its early stages, and has been interpreted as a plastic compensatory response to neuronal loss.

Moreover, the right dorsolateral prefrontal cortex (DLPFC) is commonly targeted in rTMS treatment for both and , suggesting potential overlap of neurophysiologic correlates of sleep disruption and cognitive disorder, they noted.

"The rhythmic, meditative movements of tai chi chuan are believed to reduce somatic and cognitive hyperarousal, of rTMS on cortical excitability," the editorialists wrote.

The trial included 110 older adults in China diagnosed with both a sleep disorder and mild cognitive impairment. Participants had not engaged in regular moderate intensity exercise or tai chi in the past 3 months. Mean age was 68 years and 62% were women.

During the 6-week treatment period, all participants took part in five weekly 60-minute morning sessions of tai chi. Half also received 1-Hz inhibitory rTMS over the right DLPFC delivered in 20-minute sessions five times a week in the evenings; the other half received sham rTMS.

Overall, 92% of participants completed the 6-week treatment and 12-week follow-up course. The treatment group had increased sleep efficiency at 6 weeks, measured by wrist actigraphy. Secondary outcomes at 12 weeks showed improved measures of memory and depression.

There were seven non-serious, unrelated adverse events in the study (two in the rTMS group) with no significant difference between the two groups.

Tao and colleagues acknowledged that their trial lacked actigraphy during the follow-up phase, and that participants were recruited solely from community centers in China, limiting generalizability.

"Currently, our clinical efficacy assessment relies mainly on neuropsychologic tests," they wrote. "Future studies should integrate detailed neuroimaging and physiologic assessment methods to reveal the potential mechanisms underlying the effects of these interventions," along with combined pharmacologic treatment, they suggested.

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