Obstruction of the terminal cisterna as a result of surgery for intervertebral disk prolapse

: The authors describe two cases of obliteration of the terminal cistema as a complication developing late after removal of two intervertebral disc prolapse at the levels L4/L5 and L5/S1. Intensification of pains and neurological defects with development of sphincter disturbances developed 5 and 17 years after the operation. Repeated surgical intervention brought improvement. The authors stress that compression of the dural sac by a ring-like scar had contributed to disturbances in cerebrospinal fluid circulation in the terminal cistern and was probably the cause of its obliteration.