MEASUREMENT OF LOWER-LIMB BLOOD-FLOW IN PATIENTS WITH NEUROGENIC CLAUDICATION USING POSITRON EMISSION TOMOGRAPHY

Study Design. Ten subjects (seven with neurogenic claudication and thr ee control subjects) underwent examination of lower limb muscle blood flow before and after exercise using positron emission tomography. Obj ectives. To investigate the hypothesis that lower limb muscle ischemia was the origin of symptoms in neurogenic claudication. Background. Pa tients with neurogenic claudication secondary to spinal stenosis exper ience lower limb discomfort after exercise similar to that of ischemic claudication. However, they do not have clinical evidence of peripher al vascular disease. The authors postulated that the lower limb discom fort in patients with neurogenic claudication may arise from muscle is chemia due to inadequate dilatation of arterioles in response to exerc ise, this itself arising secondary to sympathetic dysfunction due to s pinal stenosis. Method. Using O-15-labeled water and positron emission tomography measured thigh and leg muscle blood flow response to exerc ise bilaterally in seven patients with unilateral neurogenic claudicat ion and three control subjects were measured. Results. The average val ues obtained for mid-thigh and mid-calf muscle perfusion at rest were 2.57 ml/min/100 g tissue (2.23-3.90) and 2.39 ml/min/100 g tissue (2.0 3-3.46), respectively. The average valued obtained from mid-thigh and mid-calf perfusion after exercise were 4.41 ml/min/100 g tissue (2.8-6 .0) and 4.87 ml/min/100 g (2.2-11.7). We found no difference in muscle perfusion between symptomatic and asymptomatic limbs in this group of patients. Conclusion. These studies suggest that muscle ischemia is n ot the origin of symptoms in most patients with neurogenic claudicatio n.