ABSTRACTThe literature is unclear as to which muscles and how many are required for a sensitive lumbosacral radiculopathy (LSR) screen. A retrospective study of 247 electrodiagnostically confirmed LSRs in 201 patients over a 3-yr period was conducted to determine how many muscles were required to identify a LSR. All LSRs showed abnormal spontaneous activity (positive waves or fibrillation potentials) in two or more muscles innervated by the same nerve root level but different peripheral nerves. All cases were categorized by radiculopathy level, and the most frequently abnormal individual muscles were combined into different muscle screens. The frequency with which each muscle screen identified a radiculopathy was the frequency with which one or more muscles in the screen displayed abnormal spontaneous activity divided by the total number of radiculopathies. The paraspinal muscles (PM) alone identified 88percnt; of LSRs. Without PM, two muscle screens identified only 14ndash;68percnt;, three muscle screens identified 37ndash;89percnt; and four muscle screens identified 45ndash;92percnt;. Including PM, three muscle screens identified 86ndash;94percnt; of LSRs, four muscle screens identified 91ndash;97percnt; and five muscle screens yielded 94ndash;98percnt; identification. Seven to ten muscle screens resulted in minimal improvements in identifying a LSR with 98ndash;99percnt; identification. We conclude that five muscle LSR screens, including PM, are sufficient to identify LSRs while minimizing patient discomfort and examiner time.
展开▼
