Assessing Brainstem Dimensions By MRI: A Linear Analysis Based On Age, Gender, And BMI

Abstract

Background: The brainstem is vital for autonomic functions and serves as a key anatomical landmark in neuroimaging. This study aimed to establish normative reference values for brainstem diameters and assess variations based on age, gender, and body mass index (BMI) in an Indian population.

Methods: A cross-sectional MRI-based study was conducted on 157 subjects (69 males, 88 females) aged 20–60 years. Linear midsagittal measurements of the midbrain (MBAP), pons (PAP), and medulla at the pontomedullary (MPMJ) and cervicomedullary (MCMJ) junctions were obtained. Subjects were categorized by age, gender, and BMI. Statistical analyses included independent sample t-tests, one-way ANOVA, post hoc Tukey tests, and Pearson correlation.

Results: The mean AP diameters were: midbrain 1.77 ± 0.12 cm, pons 2.28 ± 0.15 cm, MPMJ 1.39 ± 0.10 cm, and MCMJ 1.07 ± 0.12 cm. Significant gender differences were found in MCMJ (p < 0.05). Age-wise, significant differences were observed in MBAP, PAP, and MPMJ (p < 0.05), with decreasing values in older age groups. Gender-based differences within age and BMI categories were also evident, particularly in MCMJ. No overall differences in brainstem diameters were noted across BMI groups, though correlations existed between some parameters.

Conclusion: This study provides normative brainstem measurements and demonstrates that age and gender significantly influence brainstem diameters. The inclusion of BMI adds a novel dimension, revealing gender-based variations in MCMJ. These findings support the use of MRI in evaluating brainstem morphology and may aid in early detection of pathological changes.