Brain functional changes in patients with botulism after illegal cosmetic injections of botulinum toxin: A resting-state fMRI study

Background: Botulinum toxin type A (BoNT-A) is generally considered safe and is widely used to treat a variety of clinical conditions involving muscle hyperactivity and for cosmetic purposes. However, the effects of BoNT-A poisoning (botulism) on brain function are poorly understood. Methodology/Principal findings: Herein, we investigated brain functions in 9 patients who received illegal cosmetic injections of botulinum and 18 matched controls by combining the analysis methods of regional homogeneity (ReHo) and amplitude of low-frequency fluctuation (ALFF) based on resting-state fMRI. Compared with the controls, the patients with botulism exhibited significantly reduced ReHo values in the left posterior lobe of the cerebellum extending to the right anterior lobe of the cerebellum, as well as in the right anterior lobe of the cerebellum extending to the parahippocampal gyrus and right posterior lobe of the cerebellum. The patients with botulism also showed weakened ALFF values in the right anterior lobe of the cerebellum extending to the left anterior lobe of the cerebellum and right posterior lobe of the cerebellum, as well as in the right anterior lobe of the cerebellum. Conclusions/Significance: The results indicate that BoNT-A may modulate cerebral activation in specific areas, which may play roles in both the adverse effects of botulism and the mechanism underlying clinical treatment with BoNT-A.