The Common Vein Copyright 2010
Definiiton
Arachnoiditis is a non-specific proliferative inflammatory process that causes a spectrum of pathological changes that mainly involves the intrathecal elements, leading to a lifelong disease process that can cause intractable pain and neurological deficit, since it can lead to formation of cysts or localized thickening overlying loss of elastic tissue in certain areas of the arachnoid.
It can be caused by the introduction of the irritant substance of a foreign body in the subarachnoid space (drugs, chemicals), trauma with bleeding, tumors, meningitis, transverse myelitis. It may appear several years after purulent meningitis or subarachnoid hemorrhage.
There are different types of arachnoiditis, depending on the location of the inflammation, also having different symptoms and clinical presentations: frontorolandic arachnoiditis, posterior fossa arachnoiditis, optochiasmatic arachnoiditis and lumbar adhesive arachnoditis.
In frontorolandic arachnoiditis, there can be hemiplegia and seizures. Arachnoiditis of the posterior fossa / cisterna magna have neurological deficits form compression of the spinal cord, associated with high CSF protein and inflammatory cells. In the optochiasmatic variety, there is decreased vision, mostly loss a central scotoma. Finally, in lumbar adhesive arachnoiditis, there are symptoms resulting from cauda equine compression, with refractory low back pain.
Diagnosis can be made thorough radiology. In IR, myelography can show thickened nerve roots, blockage of CSF flow, and CSF loculations, below the conus medullaris. These changes can be seen in MRI, which is the test of choice.
The treatment of lumbar adhesive arachnoiditis is particularly difficult; intrathecal corticosteroids may sometimes be useful.