Turkish Neurosurgery
2005 , Vol 15 , Num 3
Spinal Foraminal Arachnoid Cyst Associated With Lumbar Disc Herniation
Department of Neurosurgery, Gülhane Military Medical Academy, Ankara, Turkey
Lumbar spinal extradural arachnoid cysts are rare, expanding lesions and they
commonly occur in the thoracic spine and lie posterolaterally. Their
pathogenesis is still unclear and it is claimed that arachnoid cysts are the result
of a widening of the septum posticum. The mechanism of cyst enlargement may
be active CSF secretion from residual arachnoid matter or ball-valve effect.
Congenital, hereditary, idiopathic, and inflammatory etiologies have been
proposed. We report an extradural lumbar arachnoid cyst associated with a
lumbar disc herniation. We only performed L1-2 discectomy and left L1-L2
foraminotomy to evaluate the role of disc herniation and spinal canal stenosis
on the development of ball-valve effect which made the cyst enlarge.
Keywords :
Arachnoid cyst, lumbar spine, foraminal enlargement, disc herniation