[Lumbosciatica and nerve root anomalies]

The authors report 3 cases of lumbar pain and sciatica where operation revealed the existence of abnormalities in the distribution of L5 and S1 roots. In one case, the L5 root was not recognised within fibrous tissue also surrounding S1 and S2 and histological examination of this "fibrosis" led to the identification of nerve structures. Development of postoperative L5 paralysis showed that the L5 root was contained within the tissue non-individualised, consisting of multiple rootlets. In the other two cases the L5 and S1 roots arose from a common trunk. There was an associated herniated disc in all three cases. A review of the literature revealed the rarity of such abnormalities, as well as the fact that they were not recognised before surgery. They are difficult to recognise, even at the time of operation. The prognosis is less good than in typical lumbar pain and sciatica, essentially because of surgical difficulties of the disc curettage.