Axon reflex flare and quantitative sudomotor axon reflex contribute in the diagnosis of small fiber neuropathy

作者：Namer Barbara^*; Pfeffer Stefan; Handwerker Hermann O; Schmelz Martin; Bickel Andreas

来源：Muscle & Nerve, 2013, 47(3): 357-363.

DOI：10.1002/mus.23543

• axon reflex sweating
• axon reflex erythema
• axon reflex flare
• QSART
• small fiber neuropathy
• thermal thresholds

Introduction Objective diagnosis of small fiber impairment is difficult. Methods We used the quantitative sudomotor axon reflex test (QSART) and axon-reflex-flare-test in the foot and thigh of 46 patients with peripheral neuropathy to assess C-fiber function in addition to conventional neurography and thermal threshold testing. Results In all patients, small fiber impairment was suspected because of abnormal warmth detection thresholds (76% of all tested) and/or pain in the feet. A total of 83% had reduced axon-reflex flare areas and 17% lower QSART scores. Patients with pure small fiber neuropathy had higher rates of reduced flare areas (87.5%) and sweating rates (25.5%). There was no difference between patients with and without pain regarding thermotesting and axon-reflex testing. Conclusions Both axon-reflex tests are helpful to identify objectively patients with small fiber impairment. Afferent and efferent C-fiber classes can be impaired differently. These tests detect small fiber impairment, but they cannot differentiate between painful and nonpainful neuropathy. Muscle Nerve 47: 357363, 2013

• 出版日期2013-3