Lumbar spinal stenosis

Diseases, , ,

Synonyms:

formerly ‘pseudoclaudication’

Diagnosis:

Any developmental or acquired narrowing of the spinal canal (spinal canal stenosis), nerve root canal, or intervertebral foramina a.k.a. neural foramina, that results in compression of neural elements
Clinical features: (must be present)

  • Pain & numbness in lower back, buttocks & legs on walking or lumbar extension
  • History: Painful gait, Absence of pain while seated (symptoms exacerbated by lumbar extension, relieved by flexion)
  • Physical examination: Wide based gait, flexed posture

NCS/EMG:

  • SNAP: normal
  • CMAP: normal distal latency, conduction velocity & amplitude. In some cases amplitude may be decreased
  • H-reflex: may be absent if S1 is involved
  • F-waves: nonspecific
  • EMG: consistent with radiculopathy in multiple myotomes

CT myelgraphy: if MRI is contraindicated
MRI:

  • Asymptomatic cervical & lumbar stenosis is common. [312]
  • T2: High signal within the cord may occur, nonenhancing
  • Central canal stenosis: the spinal canal is narrowed
  • Lateral spinal stenosis: nerve root canal (from epidural sac through the intervertebral foramen) or intervertebral/neural foramina are narrowed.
  • Subarticular stenosis: area under the facet joints is narrowed
MRI features of Central spinal canal stenosis:
  • Compression of central spinal canal: graded no stenosis, mild stenosis <1 third, moderate stenosis 1 to 2 thirds, severe stenosis >2 thirds.
  • Reduction of anterior CSF space
  • Reduced or absent fluid around cauda equina
  • Hypertrophy of ligamentum flavum
  • Epidural lipomatosis
  • Reduction of posterior epidural fat
  • Nerve root sedimentation sign
  • Redundant nerve roots of cauda equina
MRI features of Lateral recess stenosis:
  • Compression of subarticular zone: graded no stenosis, mild stenosis <1 third, moderate stenosis 1 to 2 thirds, severe stenosis >2 thirds.
  • Visible nerve root compression in lateral recess

Retrolisthesis, may be present:
By definition retrolisthesis is a movement (subluxation) of >=2mm of the vetebral body posteriorly in relation to the vertebral body below it.
Retrolisthesis grading:

  • Can be graded my measuring the retrolisthesis in mm.
  • Can be graded by the intervertebral foramina IVF method:
    • Divide the intervertebral foramina into into 4 equal units.
    • Grade 1 posterior displacement of up to 25% of the IVF
    • Grade 2 posterior displacement of 25% to 50%
    • Grade 3 posterior displacement of 50% to 75%
    • Grade 4 posterior displacement of 75% to 100

Retrolisthesis classification:

  • Complete Retrolisthesis: The body of the subluxed vertebra is is posterior to both the body of the vertebra above as well as the segment below
  • Stair stepped Retrolisthesis: The body of the subluxed vertebra is posterior to the body of the vertebra above but is anterior to the one below.
  • Partial Retrolisthesis: The body of the subluxed vertebra is posterior to the body of the vertebra segment either above or below.

 

Treatment:

Consider surgery

Related articles:

References:

  1. Mamisch N, Brumann M, Hodler J, Held U, Brunner F, Steurer J; Lumbar Spinal Stenosis Outcome Study Working Group Zurich. Radiologic criteria for the diagnosis of spinal stenosis: results of a Delphi survey. Radiology 2012; 264:174–179
  2. Gustav Andreisek G, Imhof M, Wertli M, Winklhofer S, Pfirrmann C, Hodler J, Steurer J; Lumbar Spinal Stenosis Outcome
  3. Study Working Group Zurich.  A Systematic Review of Semiquantitative and Qualitative Radiologic Criteria for the Diagnosis of Lumbar Spinal Stenosis. AJR 2013; 201:W735–W746