Cysts of the sacral nerve roots; clinical significance and pathogenesis.

MY DISCOVERY in 1938 1 of cysts of the sacral nerve roots was followed in 1948 2 by my establishment of their clinical importance as one cause of the sciatic syndrome. Further experience has proved that they may be responsible also for various caudosacral syndromes. My most recent investigations have thrown light on the pathogenesis of these cysts. My original studies of the histology of the filum terminale necessitated rather complete dissections of the lower end of the spinal cord, with the sacral nerve roots and ganglia attached. Five of 30 such dissections revealed cysts of the posterior sacral nerve roots and ganglia. 1b In a later series, of 45 cadavers, cysts were encountered in five specimens, all on the sacral nerve roots (Fig. 1 A ). The subjects in the series were between 49 and 63 years of age. All cysts were concealed under the posterior arch of the sacrum,