Symptomatic gas-containing herniated disc with the vacuum phenomenon: mechanism and treatment. Case report.

A 76-year-old woman presented with an extremely rare case of symptomatic gas-containing disc herniation manifesting as left posterolateral thigh pain and ankle dorsiflexion motor weakness. The diagnosis was L3-4 vacuum disc associated with epidural pneumorrhachis. The patient underwent partial hemilaminectomy and cyst incision. After incising the cyst, the thecal sac and root were decompressed sufficiently. Vacuum disc is a common phenomenon in the elderly rarely associated with pneumorrhachis and is usually asymptomatic. Symptomatic epidural gas-containing herniated discs with the vacuum phenomenon are very rare. Gas aspiration should be considered, but excision of the gas-containing herniated disc should be performed in patients with neurological deficits, frequent recurrence, or difficult location to approach.