Diagnostic accuracy of multifidus muscle spontaneous activity by needle electromyography for the detection of lumbar foraminal and lateral exit-zone XXXX .

@entity1 @entity254 @entity809 @entity158 @entity850 @entity121
PURPOSE: The medial branch of the posterior ramus of the lumbar spinal nerve is well known to be innervated independently and to end in the multifidus muscle without @entity254 . This prospective cohort study aimed to determine the diagnostic specificity and sensitivity of @entity121 ( @entity121 ) by needle electromyography (N-EMG) for lumbar foraminal and lateral exit-zone @entity850 (LF/LEZS). METHODS: We enrolled 61 consecutive @entity1 experiencing @entity809 and/or @entity158 in the L4 or L5 regions with suspicious LF/LEZS. The Japanese Orthopedic Association (JOA) score, Visual Analog Scale (VAS) for @entity158 , and N-EMG were examined. In this study protocol, all @entity1 received at least 3  months of conservative therapy. Surgery was performed on @entity1 who experienced less than 50  % VAS @entity158 relief compared with their initial score after confirming the responsible level by lumbar nerve root block. The specificity of N-EMG was the proportion of @entity1 who improved with conservative therapies (non-surgery) after 3  months. The sensitivity of N-EMG was the proportion of @entity1 who improved with surgical therapies (surgery) after more than 12  months. RESULTS: Twenty-three @entity1 underwent surgery. The initial lower JOA, positive Kemp test and motor weakness were significantly higher in the surgery group. The @entity121 by N-EMG indicated that 34 of 38 @entity1 were negative in the non-surgery group. In the surgery group, 21 of 23 @entity1 were positive. The diagnostic sensitivity and specificity were 91.3 and 92.1  %, respectively. CONCLUSIONS: Needle electromyography is a simple and available additional method for the diagnosis of LF/LEZS.
