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Degenerative changes in the lumbar spine can be followed by cystic changes. Most reported intraspinal cysts are ganglion or synovial cysts. Ligamentum flavum pseudocyst, as a cystic lesion in the lumbar spine, is a rare and unusual cause of neurologic signs and symptoms and is usually seen in elderly persons (due to degenerative changes). They are preferentially located in the lower lumbar region, while cervical localization is rare. Complete removal of the cyst leads to excellent results and seems to preclude recurrence. We report the case of a right-sided ligamentum flavum cyst occurring at L3–L4 level in a 70-year-old woman, which was surgically removed with excellent postoperative results and complete resolution of symptoms. In addition, we discuss and review reports in the literature.

ABSTRACT.Purpose: NiCl 2 (15 lM) stimulates the electroretinogram (ERG) b-wave amplitude of vertebrate retina up to 1.5-fold through its blocking of E ⁄ R-type voltage-gated Ca 2+ channels. Assuming that such an increase is mediated by blocking the release of the inhibitory neurotransmitter c-aminobutyric acid (GABA) via ionotropic GABA receptors, we tested the effect of both GABA itself and GABA-receptor antagonists such as ())bicuculline (1.51-fold increase) and (1,2,5,6-tetrahydropyridin-4-yl)methylphosphinic acid (TPMPA; 1.46-fold increase) on the b-wave amplitude. Methods: Recording of the transretinal potentials from the isolated bovine retina. Results: GABA (100 lM) reduced the b-wave amplitude only when NiCl 2 (15 lM) was applied first. Each antagonist applied on its own stimulated the b-wave amplitude only partially: subsequent NiCl 2 superfusion caused a small but additional increase, leading to a 1.69-and a 1.88-fold total increase of the amplitude by Ni 2+ plus ())bicuculline or Ni 2+ plus TPMPA, respectively. Only the application of both antagonists in combination, before superfusing low NiCl 2 (15 lM), completely prevented subsequent stimulation by NiCl 2 with a similar 1.90-fold total increase of b-wave amplitude. Those retina segments that did not respond to NiCl 2 could not be stimulated by ())bicuculline and vice versa. Conclusion: The stimulatory effect of NiCl 2 on the ERG b-wave amplitude is mainly, but not only, mediated by a NiCl 2 -sensitive, Ca v 2.3-triggered GABA release acting through ionotropic GABA-A and GABA-C receptors.