THE PREVALENCE OF LUMBAR PARASPINAL SPONTANEOUS ACTIVITY IN ASYMPTOMATIC SUBJECTS

Electrodiagnostic findings of fibrillations and positive sharp waves i n the lumbosacral paraspinals in patients without previous back surger y has been generally considered to be abnormal, consistent with poster ior rami denervation. In some cases, it is the only abnormality on the electromyographic examination. This study was undertaken to determine the prevalence of abnormal spontaneous activity in lumbosacral parasp inals in asymptomatic individuals. Nine (14.5%) of 62 subjects studied had positive sharp waves or fibrillations noted on the needle examina tion of bilateral lumbosacral paraspinal muscles, There was a signific ant increase in the prevalence of abnormal activity with increasing ag e. This suggests that caution should be taken in attributing radiculop athy as the etiology of low back pain when electromyographic lumbosacr al paraspinal abnormalities are the only positive findings in the midd le-aged or older individual. (C) 1996 John Wiley & Sons, Inc.