Evaluation of MR-Tractography Findings in Hemifacial Spasm Patients Injected with Botulinum Neurotoxin.

Background And Introduction: Botulinum neurotoxin (BoNT) is a potent biological toxin extracted from Clostridium Botulinum bacteria. BoNT injection is mainly used for medical purposes; it is frequently used for cosmetic purposes as well. The hypothesis that frequent application of this treatment modality may also affect the central nervous system constitutes the subject of our study.

Objective: We aimed to demonstrate the possible central effects of BoNT in hemifacial spasm patients.

Methods And Materials: Diffusion tensor imaging was used for this study. Patients were divided into two groups, and the measured values for each determined bilateral neuroanatomic region were compared within the relevant group.

Results: Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were found to be closer to the pathological values in the right motor cortex and in the left internal capsule areas of the patients who were injected with BoNT into the left side, in the left motor cortex area of the patients who were injected with BoNT into the right side. No significant changes were detected in other regions.

Conclusion: Botulinum neurotoxin administration in patients with hemifacial spasms may cause some changes in the central nervous system as well as peripheral effects. In the case of similar studies supporting pathological changes, BoNT treatment modalities or appropriate indications may be reviewed, and regulation on excessive cosmetic use may be in question.