Lower Extremity Pain



Lower Extremity Pain


Bryson Borg, MD



DIFFERENTIAL DIAGNOSIS


Common



  • Intervertebral Disc Bulge


  • Intervertebral Disc Herniation


  • Stenosis, Acquired Spinal, Lumbar


  • Stenosis, Foraminal, Lumbar


  • Stenosis, Congenital Spinal


  • Spondylolisthesis


  • Spondylolysis


  • Metastases


Less Common



  • Abscess, Epidural, Paravertebral


  • Hematoma, Epidural-Subdural


  • Ependymoma, Myxopapillary, Spinal Cord


  • Neurofibroma


  • Schwannoma


  • Facet Joint Synovial Cyst


  • Arachnoiditis, Lumbar


  • Primary Bone Tumor



    • Multiple Myeloma


    • Osteoid Osteoma/Osteoblastoma


    • Osteosarcoma


    • Chondrosarcoma


  • Femoral Neuropathy


  • Retroperitoneal Hematoma


  • Tethered Spinal Cord


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • Majority of lower extremity pain due to pathology within the extremity



    • Osteoarthritis of the hip or knee


    • Meniscal pathology


    • Tendinous or ligamentous injury


    • Trauma


    • Deep venous thrombosis


    • Infection/inflammation


    • Neoplasms of the soft tissues and bone


  • Neurogenic leg pain due to impingement on the distal cord or nerve roots in the spinal canal, neuroforamina, or retroperitoneum


  • Also consider vascular claudication as a remote source of lower extremity pain


Helpful Clues for Common Diagnoses



  • Intervertebral Disc Bulge



    • Diffuse (> 50% circumference) extension of the disc beyond its normal margins


  • Intervertebral Disc Herniation



    • Classified morphologically



      • Protrusion: Wider than deep, limited by adjacent endplates on sagittal images


      • Extrusion: Deeper than wide or extends beyond either adjacent endplate on sagittal images


      • Sequestration: Herniated disc not in continuity with the remaining disc


  • Stenosis, Acquired Spinal, Lumbar



    • Multifactorial process


    • Relative lumbar canal stenosis: < 12 mm; absolute lumbar canal stenosis: < 10 mm


  • Stenosis, Foraminal, Lumbar



    • Multifactorial process


    • Loss of fat within the neural foramen on sagittal T1WI


  • Stenosis, Congenital Spinal



    • Developmental narrowing of the lumbar canal and neural foramina due to short, squat pedicles


    • Otherwise mild degenerative changes in disc and posterior elements can result in symptomatic stenosis


  • Spondylolisthesis



    • Displacement of a vertebral body relative to the inferior vertebra


    • Direction



      • Anterolisthesis


      • Retrolisthesis, usually degenerative etiology


      • Lateral listhesis


    • Etiology



      • Degenerative, secondary to loss of intervertebral disc height and laxity in facet joints


      • Spondylolytic


      • Traumatic


  • Spondylolysis



    • Defect of pars interarticularis, may be unilateral or bilateral


    • Classified into early, progressive, and terminal stages (Morita)


    • Hairline fracture of early stage often difficult to appreciate with CT



      • Fracture can be suggested by MR (hyperintense STIR) or SPECT (tracer avid)


    • Unilateral spondylolysis associated with increased risk of contralateral pars fracture


  • Metastases



    • Common primaries: Breast, lung, kidney, prostate



    • Lesions typically multiple


    • Either lytic or sclerotic on CT, typically hypointense T1/hyperintense T2 signal on MR


    • Either epidural tumor or pathologic vertebral compression fracture can impinge on nerve roots or the cord


Helpful Clues for Less Common Diagnoses

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Aug 7, 2016 | Posted by in NEUROLOGY | Comments Off on Lower Extremity Pain

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