Proton magnetic resonance spectroscopic studies of hypertrophied muscle. Effect of botulinum toxin treatment.

In vivo image-guided localized proton magnetic resonance spectroscopy (MRS) studies have been performed in a patient with hypertrophied tibialis anterior (TA) muscle and following two injections of botulinum toxin into the affected muscle. Prior to treatment, lipid levels in hypertrophied muscle were found to be low compared to normal. Lipid levels were observed to approach control levels after the second injection. Three months following treatment the trend in exercise-induced changes in lipids was observed to be similar between the hypertrophied and normal TA muscle. This preliminary report demonstrates the potential clinical utility of MRS in evaluating patient response to medical treatment.