Acupuncture at the Taixi (KI3) acupoint activates cerebral neurons in elderly patients with mild cognitive impairment

This study investigated the effects of acupuncture at the Taixi (KI-3, 太溪) point on brain activation in older adults with mild cognitive impairment (MCI) using functional magnetic resonance imaging (fMRI). Mild cognitive impairment represents an intermediate stage between normal aging and dementia, and is crucial for the prevention of Alzheimer's disease. The study compared 12 patients with MCI and 12 healthy controls, all aged 55-70 years. The Taixi (KI-3, 太溪) point, located at the ankle, is traditionally used in Chinese medicine to treat cognitive disorders and is related to the kidney system according to TCM theory.

The experimental protocol consisted of a 22-minute fMRI session, including 6 minutes of resting state followed by 3 minutes of acupuncture stimulation. A silver needle was inserted perpendicularly to a depth of 12 mm at the right Taixi point, followed by manipulation by rotation for 2 minutes. The results showed that acupuncture activated the same 20 brain regions in both groups, including areas fundamental to cognitive function such as the anterior cingulate cortex, medial frontal cortex, inferior and superior frontal gyri, precuneus, and associative visual areas. These regions are directly related to memory, learning, attention, and emotional processing.

Particularly important were activations in Brodmann areas 9, 10, and 11 of the prefrontal cortex, which are executive centers of cognition. The limbic system was also broadly activated, including the cingulate cortex (areas 24 and 32), crucial for emotional regulation and memory. There were no significant differences in needling sensations between the groups, indicating similar tolerability. The reported sensations included mainly moderate pain, numbness, a sense of fullness, and warmth.

The study recorded no adverse events, confirming the safety of the procedure. Activation of visual areas (areas 18 and 19) was also observed, which is consistent with TCM theory that associates the kidney with the liver and the latter with the eyes. The findings suggest that acupuncture at the Taixi point may be a promising intervention for MCI, specifically activating cognition-related neural networks. The study contributes to the understanding of the neurobiological mechanisms of acupuncture and provides a scientific basis for its clinical use in cognitive disorders.

The research is particularly relevant given that medications for MCI have limited efficacy and potential adverse effects, whereas acupuncture offers a safe and well-tolerated alternative.