Abstract: BACKGROUND: Currently, traditional Chinese medicine has accumulated extensive experience in the treatment and management of ischemic stroke. The application of latent structure combined with association rule analysis to deeply explore and summarize the “medicine-prescription-syndrome” rules is conducive to promoting the optimization of ischemic stroke prevention and treatment strategies. 
OBJECTIVE: To explore the rules of Chinese medicine in the treatment of ischemic stroke, and provide a reference for the clinical treatment of ischemic stroke based on syndrome differentiation
METHODS: A systematic search was conducted for clinical research literature on traditional Chinese medicine treatment of ischemic stroke from China National Knowledge Infrastructure (CNKI), WanFang, VIP, and SinoMed databases, covering the period from January 1, 1990, to August 15, 2024. The relevant studies were selected and the data were extracted into an Excel 2019 database for analysis. The frequency of use of Chinese herbs, their properties, meridional tropism, therapeutic effects and associated syndromes were analyzed. High-frequency herbs (≥ 4%) were subjected to latent structure modeling, comprehensive clustering, and association rule analysis using Lantern 5.0 and RStudio software, followed by summary of medication patterns and potential traditional Chinese medicine syndromes for ischemic stroke.
RESULTS AND CONCLUSION: (1) A total of 231 articles were included, involving 203 kinds of traditional Chinese medicine, and the frequency of use was 2 524 times. (2) The high-frequency Chinese herbs were Chuanxiong, Earthworm, Angelica, Astragalus, Salviorrhiza, red peony root, safflower, leech, peach kernel, and pinellia. These herbs had predominantly warm, cold, or neutral properties, with bitter, sweet, and pungent flavors. Primary meridional tropism targets the liver, spleen and heart. Drug for invigorating blood circulation and eliminating stasis, deficiency tonifying drug, calming liver wind drug, expectorant cough suppressant and anti-asthmatic drug were used more frequently. (3) The latent structure model analysis identified 7 latent variables, 14 latent classes, 6 comprehensive clustering models, and 19 core prescriptions. It is hypothesized that the main traditional Chinese medicine syndromes for ischemic stroke are qi deficiency and blood stasis syndrome, wind-phlegm obstructing the channels syndrome, phlegm and blood stasis obstructing the channels syndrome, and phlegm-heat obstructing the viscera syndrome. (4) The association rule analysis revealed 29 strongly associative rules, including 2 two-item rules and 27 three-item rules. The highest degree of support was Angelica-Chuanxiong, and the highest degree of confidence was Angelica + licorice-Chuanxiong. The results show that ischemic stroke is a syndrome with qi and blood deficiency, liver and kidney Yin deficiency as the root causes, and wind, phlegm, blood stasis, and fire as the manifestations. The treatment is mainly to benefit qi and strengthen health, promote blood circulation and remove blood stasis, combined with pathological factors such as “phlegm and heat,” “qi stagnation,” “Yin deficiency,” and “liver fire,” supplemented by clearing heat and phlegm, promoting qi stagnation, nourishing liver and kidney, clearing liver and reducing fire. 

Key words: ischemic stroke, latent structure model, association rule, prescription law, synthetic clustering, data mining, LTM-EAST algorithm, Chinese medicine