title: Clinical and electrophysiological appraisal of the significance of radicular injury in back pain.
abstract: Clinical electrophysiological studies were analysed in 60 consecutive patients with back pain with or without other evidence for a radiculopathy. These studies included needle EMG of relevant limb and paraspinal muscles as well as F responses and H reflexes recorded from the soleus muscle. Segmental denervation was found in 29 of the 60 patients. In 57 patients, abnormal slowing of the F response was present in 27, either unilaterally (25) or bilaterally (two). In 18 of 47 patients with H reflex studies, the H reflex was either unilaterally absent (12), asymmetrically prolonged (five), or bilaterally prolonged (one). Statistically significant (P less than 0.05) associations were found between (1) abnormalities of H reflexes and F responses, (2) F response slowing and radicular injury shown by EMG, (3) segmentally consistent radiographic defects and abnormalities of both H reflexes and F responses, and (4) depressed Achilles reflexes as well as sensory loss and abnormal H reflexes. No significant association, however, was present between abnormalities of EMG, F responses, or H reflexes and pain radiation by history or positive straight leg-raising tests. These data suggest that pain in radicular syndromes is related to the functioning of smaller afferent fibres.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001416:Back Pain / Q000503:physiopathology*; D004576:Electromyography; D006801:Humans; D008875:Middle Aged; D010523:Peripheral Nervous System Diseases / Q000503:physiopathology*; D011930:Reaction Time; D012021:Reflex, Abnormal; D012023:Reflex, Monosynaptic; D013126:Spinal Nerve Roots / Q000503:physiopathology*