Abstract
Background:
Lumbar intraspinal cysts (LICs) are rare incidental MRI findings in back pain. Their space-occupying nature make them plausible factors in both non-specific and radicular back pain.
Methods:
Retrospective cohort study of patients with MRI reports of LICs at our center over 5 years. N=26, 13 male, mean age 66 ± 12 years.
Results:
LICs originated at levels from L1-S2 (61.5% at L4/5), reaching 17mm2 (rapid one year progression in this case). LICs were described as synovial in all but two cases (hemorrhagic cyst; Tarlov perineural cysts). Background degenerative changes were reported in 88.5% of cases. Patients described up to 30-year histories of non-specific back pain. Clinical features of radiculopathy plus concomitant MRI findings were indications for surgical decompression (n=14) and cyst excision (n=13/14). 2 cases of spontaneous LIC resolution, and 2 cases of post-operative complications were identified (inflammatory/scar tissue stenosis). 0% cyst recurrence rate with sustained resolution of symptoms currently stands.
Conclusions:
Frequent co-existence of LICs with degeneration implicates the former as a product of osteoarthritic processes, conceivably contributing to patient accounts of chronic non-specific pain. LICs may equally constitute acute direct causes of radiculopathy, owing to their diverse origins and potential to rapidly expand. A role of LICs in axial and radicular pain, independent of other degenerative changes, is supported by symptom alleviation in cases of spontaneous resolution, versus progression with decompression performed without cyst excision (Tarlov cyst), or following novel cyst formation at the level of previous spinal fusion. Whether image-guided aspiration might reduce surgery-related side-effects is a topic for further work.
