The consequence of this retrospective, nationwide, population-based cohort study illustrates significant associations between post-stroke dementia and application of acupuncture. The best methods to prevent post-stroke dementia are to impede recurrence of stroke and reduce severity of stroke-related impairment through the most favourable acute treatment and intensive secondary prevention [20–22]. Secondary prevention consists of medical interventions and lifestyle modification. To date, advanced treatment for vascular risk factors and vascular disease may prevent post-stroke dementia. An observational study unveiled reduced cognitive impairment in patients with appropriate post-stroke vascular risk management, including antiplatelet therapy, antihypertensive drugs and statins, or anticoagulants, as indicated. Furthermore, cognitive function can benefit from therapy for neuropsychiatric symptoms like depression, apathy, and anxiety, as well as cognitive training/stimulation. According to our results, we suggest that early intervention with acupuncture could also decrease the risk of post-stroke dementia.
Acupuncture as a traditional Chinese healing technique treats disorders by inserting needles into specific acupoints, and it is generally considered safe when performed correctly. The use of acupuncture treatment for 43 diseases has been recommended by the World Health Organization, and as a non-pharmacological intervention, it is considered to be an alternative treatment for dementia[10–14]. In a recent animal study, improvement in cognition and hippocampal synaptic plasticity induced by acupuncture was achieved via activation of dopamine D1/D5 receptors.
After adjusting for geographic characteristics, region of residence and selected comorbidities, the proportion of men with diagnosis of stroke was a bit higher than that of women in both cohorts (53.48% vs. 46.52%) during this 3-year follow-up. The selected comorbidities were more prevalent in the stroke cohorts compared with the non-stroke cohorts. The mean age of the patients in the cohorts was 66.02 ± 11.72 years. In another study, older adults, residents in southern and eastern regions, patients with low insurance range, and antiplatelet use were prominent risk factors of post-stroke dementia in Taiwan.
We demonstrated that patients with stroke had significantly higher incidence of dementia rates within 3-year follow-up, and the incidence of dementia in male patients with stroke was higher than that of female patients with stroke. A pooled analysis of international data classified important contributors and risk factors to post-stroke dementia, and age over 65 and female gender are the mentioned risk factors[26, 27]. The mean age in our study and the result that stroke patients had higher incidence of dementia match with this analysis, however the effect of gender did not. Although there was no statistical significance, the proportion of male patients with diagnosis of stroke in our study was higher. Li CH et.al claimed that patients with stroke were at significantly more risk of dementia during the 5- and 10-year follow-up periods in Taiwan. Post-stroke dementia is often recognized in the first weeks to months post-ictus, and thereafter, prevalence of post-stroke dementia increases with time. Ethnic differences and a longer follow-up period should be considered.
The relationship between stroke and neurodegenerative diseases, such as AD and VD, has been established[1, 2–5]. VD is the second most common cause of cognitive decline, with only AD being more prevalent. Multicellular interactions within the neurovascular unit, including damage to the blood-brain barrier, neuronal cell death or degeneration, glial reaction, and immune cell infiltration contribute to the aetiology. Our results indicated stroke patients with subsequent acupuncture treatment were less likely to develop several subtypes of dementia during the 3-year follow-up. Notably, the adjusted HR for unspecified dementia in patients with acupuncture was 0.49 (95% CI, 0.41–0.59; p < 0.001). Pathological mechanisms of AD are poorly understood, and approximately 70% of the risk is believed to be inherited, with many genes being involved. VD can also result from other conditions besides stroke that damage blood vessels and reduce circulation. This may explain why these most common aetiologies of dementia did not show statistical significance in our study, although there was a trend toward affirmative efficacy.
There is no obvious evidence to support any specific mechanism that contributes to the effect of acupuncture in decreasing the incidence of post-stroke dementia. Researchers have discovered that this therapy may reduce oxidative stress, attenuate neuronal apoptosis, relieve neuroinflammation, regulate glucose metabolism, modulate neurotransmitters, and improve synaptic plasticity and blood vessel function . Interestingly, we discovered evidence that revealed that those patients who received acupuncture were at a lower risk of developing dementia regardless of whether they had the diagnosis of stroke or not. Patients who choose acupuncture as a complementary treatment may place more emphasis on personal health maintenance with regard to better knowledge and attitudes for disease prevention. These factors could also contribute to reduced incidence of dementia.
A retrospective, nationwide cohort was employed in our study, which provided a large sample size and more evidence compared to case-control or cross-sectional study designs. Problems like insufficient power and the effect of selection biases were minimized. However, our study had several limitations. First, the insurance claims data we collected lacked information regarding clinical risk scores (such as the National Institutes of Health Stroke Scale or the Barthel Index), characteristics of the lesion, its location, size, laboratory examination results, and factors of patients’ lifestyle such as cigarette smoking, alcohol consumption, and physical activity. Second, this study could not validate the actual acupoints used in the treatment of the stroke patients, as limited information is provided by the National Health Insurance Research Database. The acupoints chosen by traditional Chinese medicine physicians for stroke patients vary, and the beneficial effects are somewhat different. Further studies need to be carried out to identify the protective effects against dementia from individual acupoints. Finally, residual confounding data is always present, even though we had utilized multivariate regression adjustments for several potential confounding factors in our analysis.