Impaired somatosensation in patients with isolated proximal-without-distal exercise-related lower-limb ischemia

OBJECTIVES: Isolated proximal-without-distal (buttock but not calf) exercise-related lower-limb ischemia (IPI) might develop in the presence of arterial lesions impairing the blood flow supply toward the hypogastric vascular bed. In IPI, lower-limb sensory nerve dysfunction might occur from the sacral nerve plexus becoming ischemic during exercise. The purpose of this study was to compare patients with IPI with healthy controls for the presence of sensory nerve dysfunction, as assessed using somatosensory testing (SST).

METHODS: Seventeen nondiabetic patients with IPI and 17 age-matched and sex-matched healthy controls underwent SST of both the upper and lower limbs.

RESULTS: The upper-limb SST data did not differ between groups (P>0.05). In contrast, lower-limb testing showed that patients with IPI had impaired warm (43.4±2.7 vs. 40.5±4.9°C) and vibration (5.0±2.3 vs. 6.4±1.4 arbitrary units) detection thresholds compared with healthy controls (P≤0.05). Furthermore, lower-limb mechanical detection threshold and Neuropathy Symptom and Disability Scores tended to be higher in the patients (P≤0.10).

DISCUSSION: The SST data suggest that patients with IPI have abnormal functioning of Aβ-fiber and C-fiber inputs in their affected limb(s). These sensory abnormalities might contribute to the exercise-induced ischemic symptoms experienced by these patients.