Intradural lumbar disc herniation: report of two cases.

Intradural lumbar disc herniation (ILDH) is a rare pathology. The pathogenesis of ILDH is not known with certainty. Adhesions between the ventral wall of the dura and the posterior longitudinal ligament (PLL) could act as a preconditioning factor. Diagnosis of ILDH is difficult and seldom suspected preoperatively. Prompt surgery is necessary because the neurologic prognosis appears to be closely linked to preoperative duration of neurologic symptoms. Despite preoperatively significant neurological deficits, the prognosis following surgery is good. We report on two new cases of ILDH of high lumbar locations L1-2 and L2-3 with difficult differential diagnoses, and the possible pathogenic factors are discussed.