Use of botulinum toxin type A in symptomatic accessory soleus muscle: first five cases.

Symptomatic accessory soleus muscle (ASM) can cause exercise-induced leg pain due to local nerve/vascular compression, muscle spasm, or local compartment syndrome. As intramuscular injections of botulinum toxin type A (BTX-A) can reduce muscle tone and mass, we investigated whether local BTX-A injections relieve the pain associated with symptomatic ASM. We describe five patients presenting peri/retromalleolar exertional pain and a contractile muscle mass in the painful region. Com-pression neuropathy was ruled out by electromyo-graphic analysis of the lower limb muscles. Doppler ultrasonography was normal, excluding a local vascular compression. ASM was confirmed by magnetic resonance imaging. After a treadmill stress test, abnormal intramuscular pressure values in the ASM, confirmed the diagnosis of compartment syndrome only in one patient. All five patients received BTX-A injections in two points of the ASM. The treatment efficacy was evaluated based on the disappearance of exercise-induced pain and the resumption of normal physical and sports activities. After BTX-A injection, exertional pain disappeared and all five patients resumed their normal level of physical and sports performances. Neither side effects nor motor deficits were observed. BTX-A is well tolerated in patients with ASM and could be used as a new conservative therapeutic strategy for the treatment of symptomatic ASM before surgery.

Microbiopsies versus Bergström needle for skeletal muscle sampling: impact on maximal mitochondrial respiration rate.

INTRODUCTION: Microbiopsies are increasingly used as an alternative to the standard Bergström technique for skeletal muscle sampling. The potential impact of these two different procedures on mitochondrial respiration rate is unknown. The objective of this work was to compare microbiopsies versus Bergström procedure on mitochondrial respiration in skeletal muscle. METHODS: 52 vastus lateralis muscle samples were obtained from 13 anesthetized pigs, either with a Bergström [6 gauges (G)] needle or with microbiopsy needles (12, 14, 18G). Maximal mitochondrial respiration (V GM-ADP) was assessed using an oxygraphic method on permeabilized fibers. RESULTS: The weight of the muscle samples and V GM-ADP decreased with the increasing gauge of the needles. A positive nonlinear relationship was observed between the weight of the muscle sample and the level of maximal mitochondrial respiration (r = 0.99, p < 0.05) and between needle size and maximal mitochondrial respiration (r = 0.99, p < 0.05). CONCLUSION: Microbiopsies give lower muscle sample weight and maximal rate of mitochondrial respiration compared to the standard Bergström needle.Therefore, the higher the gauge (i.e. the smaller the size) of the microbiopsy needle, the lower is the maximal rate of respiration. Microbiopsies of skeletal muscle underestimate the maximal mitochondrial respiration rate, and this finding needs to be highlighted for adequate interpretation and comparison with literature data.