Assessment of the Length of the Anterior and Posterior Commissure Lines According to Gender and Age

Aim: There are variations in the size and shape of the skull based on factors such as race, age, and gender. The anterior and posterior commissures are significant brain regions that serve as essential reference points for stereotactic and functional neurosurgical procedures, human brain mapping, and medical imaging techniques. Our study analyzed the length of the anterior-posterior commissure (AC-PC) with these demographic factors in patients who underwent deep brain stimulation (DBS) in the Turkish population. Method: A total of 101 individuals, comprising 64 men and 37 women, were included in the study. Data were collected through magnetic resonance imaging performed according to the DBS protocol, with the anterior commissure (AC) and posterior commissure (PC) markings conducted using the StealthStationTM S8 Planning program. Receiver Operating Characteristic (ROC) analysis was performed to distinguish between male and female AC-PC measurements. Results: The mean age of all participants was 60.32±11.31 years (range: 30-85), and the average AC-PC distance was 24.18±2.03 mm (range: 20.01-28.7). The AC-PC distances of males (24.83±1.986 mm) were statistically significantly greater than those of females (23.06±1.592 mm). A weak positive correlation was observed between the ages and AC-PC distances of the participants (r=0.432, P<0.001). According to the results of the univariate regression analysis, each additional year of age in males was associated with an increase of 0.083 mm (95% CI: 0.045 – 0.121) in AC-PC distance (R²=0.235, P<0.001). Conclusion: A comparison of data obtained from other studies indicates that the AC-PC distance in individuals of Turkish descent is nearly similar to that of the Asian population, yet shorter than that observed in Caucasian populations and even shorter than in Hispanic populations. These findings highlight the variation in AC-PC distances associated with ethnic origin.