Transcutaneous neuromodulation at ST36 trumps tibial nerve stimulation in treating constipation
Transcutaneous neuromodulation (TN) at acupoint Zusanli (ST36) appears to be more potent than TN at posterior tibial nerve (PTN) in the treatment of constipation and its related symptoms and rectal sensation, a study has shown.
Nine male and nine female functional constipation patients participated in this crossover study with a 2-week TN at ST36 and a 2-week TN at PTN. Participants completed a bowel movement diary, as well as the questionnaires of Patient Assessment of Constipation Symptom (PAC-SYM) and Constipation Quality of Life (PAC-QoL). The investigators also performed anorectal manometry and spectral analysis of heart rate variability for assessing the autonomic function.
Both TN at ST36 and at PTN improved constipation-related symptoms (PAC-SYM scores on pre-TN vs post-TN: 1.4±0.1 vs 0.6±0.1 for ST36; 1.4±0.1 vs 0.9±0.1 for PTN; pboth≤0.001). TN at ST36 increased the number of weekly spontaneous bowel movements (pre-TN vs post-TN: 0.9±0.2 vs 3.5±0.7; p<0.001) and decreased the total PAC-QoL score, but TN at PTN did not. Moreover, TN at ST36 was more effective than TN at PTN in improving PAC-SYM score (decrement: 0.8±0.1 vs 0.5±0.1; p<0.05).
TN at ST36, but not at PTN, reduced sensation thresholds, including rectal distention for urge (pre-TN vs post-TN: 134.1±14.3 vs 85.6±6.5 mL; p<0.01) and maximum tolerance (p<0.05). Finally, both TN at ST36 and at PTN resulted in significant increase in vagal activity and decrease in sympathetic activity (p<0.05).
“Combined TN at acupoint ST36 and TN at PTN has been reported effective in treating functional constipation,” the investigators noted.