Distinctive Characteristics of Thoracolumbar Junction Region Stenosis

Abstract

Study Design: Retrospective case series and systemic literature meta-analysis. Background: Thoracolumbar junction region stenosis produces spinal cord compression just above the conus and may manifest with symptoms that are not typical of either thoracic myelopathy or neurogenic claudication from lumbar stenosis. Objective: As few studies describe its specific pattern of presenting symptoms and neurological deficits, this investigation was designed to improve understanding of this pathology. Methods: A retrospective review assessed surgically treated cases of T10–L1 degenerative stenosis. Clinical outcomes were evaluated with the thoracic Japanese Orthopedic Association score. In addition, a systematic review and meta-analysis was performed in accordance with guidelines provided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Results: Of 1069 patients undergoing laminectomy at 1477 levels, 31 patients (16M/15F) were treated at T10–L1 a mean age 64.4 (SD=11.8). Patients complained of lower extremity numbness in 29/31 (94%), urinary dysfunction 11/31 (35%), and back pain 11/31 (35%). All complained about gait difficulty and objective motor deficits were detected in 24 of 31 (77%). Weakness was most often seen in foot dorsiflexion 22/31 (71%). Deep tendon reflexes were increased in 10 (32%), decreased in 11 (35%), and normal 10 (32%); the Babinski sign was present 8/31 (26%). Mean thoracic Japanese Orthopedic Association scores improved from 6.4 (SD=1.8) to 8.4 (SD=1.8) (P<0.00001). Gait subjectively improved in 27/31 (87%) numbness improved in 26/30 (87%); but urinary function improved in only 4/11 (45%). Conclusions: Thoracolumbar junction stenosis produces distinctive neurological findings characterized by lower extremity numbness, weakness particularly in foot dorsiflexion, urinary dysfunction, and inconsistent reflex changes, a neurological pattern stemming from epiconus level compression and the myelomeres for the L5 roots. Surgery results in significant clinical improvement, with numbness and gait improving more than urinary dysfunction. Many patients with thoracolumbar junction stenosis are initially misdiagnosed as being symptomatic from lumbar stenosis, thus delaying definitive surgery.