Fractal Dimension in Healthy Hippocampi and Hippocampi With Mesial Temporal Sclerosis: An Observational Study

A fractal is a geometric shape that has the same structure across a wide range of scales. The existence of fractal dimension has been demonstrated in various natural structures and translated into a mathematical method through which anatomical structures can be measured with high precision. The hippocampus, located in the mesial area of the temporal lobe, is affected in diseases such as epilepsy, tumors, and viral infections. Mesial temporal sclerosis (MTS) is a condition that significantly degenerates hippocampal neurons and is a major cause of drug-resistant epilepsy. This study aimed to compare the fractal dimension between healthy hippocampi and hippocampi with MTS, and to determine whether there is a difference between them. We analyzed preoperative magnetic resonance imaging (MRI) scans from 12 patients with MTS, calculating the fractal dimension of both the diseased and the contralateral healthy hippocampus using the box-counting method in ImageJ. Healthy hippocampi had a mean fractal dimension of 1.305, while those with MTS had 1.243, representing a 4.75% reduction (p = 0.008). These results suggest that fractal dimension could serve as a quantitative biomarker for hippocampal degeneration in MTS, potentially aiding in earlier diagnosis, guiding treatment strategies, and contributing to research on structural brain changes in epilepsy.