Features of facial expressions in patients with cognitive impairment due to Alzheimer’s disease

Objective. To determine the prospect of using the author’s method of video analysis of facial expressions as an auxiliary method in diagnosing Alzheimer’s disease. Material and methods. The study included clinically healthy individuals (n=37) and patients (n=34) with neurocognitive disorder (NCD) caused by Alzheimer’s disease. The patients were divided into subgroups of subjects with “mild” NCD (n=16) and “major” NCD (n=18). The method is based on a no-contact capture of 68 key points of the face. Kinetic indicators of eyebrow, eyelid, and mouth movements are analyzed during the following diagnostic tests: “Smile”, “Drawing the letter O with the lips”, “Blinking”, “Raising eyebrows”, “Frowning eyebrows”, and “Reading the test”. Results. When comparing the obtained data on the state of facial expressions of healthy individuals with a group of patients, a statistically significant difference (p<0.05) was found in the amplitude and speed of movements of the eyebrows, eyelids, and mouth. Significant differences (p<0.05) in “Smile frequency”, “Eyebrow raising frequency”, and “Eyebrow raising amplitude along the X axis” indicators were also found between the two subgroups of patients with NCD. In the subgroup of patients with “major” NCD compared to “mild” NCD, there was a decrease in the amplitude of eyebrow raising along the X-axis, the frequency of eyebrow raising by approximately 2 times, and the smile frequency by 1.6 times. Conclusion. The method is promising as a screening and additional diagnostic tool in patients with suspected Alzheimer’s disease. However, further studies are required to determine its diagnostic value.