[Anomalies of the pattern of lumbosacral nerve roots and its clinical significance (author's transl)].

Twenty personal observations and 18 cases collected from the literature are analysed. The most frequently encountered anomaly were: common dural origin of 2 nerve roots and common exit of 2 nerve roots through the intervertebral foramen. Other anomalies comprised: interradicular connections and Y-shaped or horizontla course of the nerve root. Multiple anomalies were not encountered. In 9 out of 20 patients in the own series and in 6 out of 18 patients reported in the literature, history and clinical findings suggested prolapsed intervertebral disc, operation revealed only nerve root anomalies. Decompression produced improvement or complete relieve of previously existing signs and plain X-rays is not possible. The diagnosis is based on myelographic findings. The pathogenesis of the anomalies is discussed. It is suggested that they should not be considered as a causative factor of low back pain or sciatica.