Focal Ligamentum Flavum Hypertrophy with Ochronotic Deposits: An Unusual Cause for Neurogenic Claudication in Alkaptonuria

Abstract

Neurogenic claudication resulting from focal hypertrophy of the ligamentum flavum in the lumbar spine due to ochronotic deposits has not been reported till date. The authors discuss one such case highlighting the pathogenesis, histological and radiological features. Salient features of management are also emphasized upon.

Black-Colored Ligamentum Flavum Due to Alkaptonuria

“…In all the published case reports of lumbar and dorsal disk prolapse in ochronotic patients, ours was the second one after Reddy et al described the first case of ligamentum flavum hypertrophy with ochronosis. 2 Our patient with this metabolic disease had very thin dura mater, which might have been unique to our case. We suggest that ochronotic patients may have more spinal pathologies, and these patients and their complaints of pain should be considered more carefully with respect to their metabolic pathology.…”

“…Scribonius first described the urinary manifestations of the disease in 1584, and Boedeker in 1858 recognized the presence in urine of a reducing substance (alkapton) with an affinity for oxygen in an alkaline medium. 2 Large quantities of HGA are excreted daily in the urine, where it oxidizes to benzoquinones, which in turn form the melanin-like polymers that cause the discoloration of urine. Accumulation of HGA and its metabolites in tissues causes ochronosis.…”

“…1 Reddy et al first reported ligamentum flavum hypertrophy with an ochronotic deposit. 2 This report will be the second one on the subject. We present the clinical, radiologic, and histologic manifestations of an ochronosis case with a brief review of the literature.…”

Black colored intervertebral disc; ochronosis: A case report

“…Generalized osteophytes are common in the elderly. [7][8][9] In the MRI obtained from our patient, we observed L 4-5 extruded disc hernia and significant degenerative changes at thoracolumbar junction ( Figure 2).…”

“…Confirmatory tests for diagnosis are chromatographic, enzymatic, or spectrophotometric determinations of HGA. [6,7] In conclusion, diagnosis of ochronosis is quite difficult without suspicion of the disease. Dark pigmentation of ear cartilage, urolithiasis and multiple joint complaints are hints for ochronosis disease and darkening the urine one hour after micturition supports the diagnosis.…”