title: Correlation of lateral stenosis in MRI with symptoms, walking capacity and EMG findings in patients with surgically confirmed lateral lumbar spinal canal stenosis.
abstract: BACKGROUND
  To evaluate the clinical significance of lateral lumbar spinal canal stenosis (LLSCS), found by magnetic resonance imaging (MRI), through correlating the imaging findings with patient symptoms, walking capacity and electromyography (EMG) measurements.
  
  
  METHODS
  102 patients with symptoms of LSS referred for operative treatment were studied in this uncontrolled study. Of these patients, subjects with distinct only lateral LSS were included. Accordingly, 140 roots in 14 patients (mean age 58, range 48-76 years, male 43%) were evaluated. In MR images the entrance and mid zones of the lateral lumbar nerve root canal were graded as normal, narrowed but not compressed, or compressed. In quantitative analysis, the minimal widths of the lateral recess and mid zone area were measured. Clinical symptoms were recorded with the Oswestry Disability Index (ODI), overall Visual Analogue Scale (VAS), specific low back pain (LBP; NRS-11), specific leg pain (LP NRS-11), Beck Depression Inventory (BDI) and walking distance in the treadmill test. Lumbar paraspinal (L2- L5) and lower limb (L3 - S1) needle EMG studies were performed. The findings were classified root by root as 1 = normal, 2 = abnormal. The associations between radiological, EMG and clinical findings were tested with each other.
  
  
  RESULTS
  EMG findings were normal in 92 roots and abnormal in 48 roots. All of the patients had at least one abnormal nerve root finding. Severity of the mid zone stenosis in MRI correlated with abnormal EMG findings (p = 0.015). Patients with abnormal EMG had also higher scores in the VAS (41.9 ± 25.7 vs 31.5 ± 18.1; p = 0.018), NRS leg pain (7.5 ± 1.5 vs 6.3 ± 2.1; p = 0.000) and BDI (9.8 ± 3.8 vs 8.0 ± 3.9; p = 0.014). However, no statistically significant correlations between MRI findings and clinical symptoms or walking capacity were found.
  
  
  CONCLUSIONS
  Among persons previously selected for surgery, lateral stenosis seen on MRI correlates with EMG, and thus may be a clinically significant finding. Our EMG findings were also associated with patient symptoms. However, no relationships between the MRI findings and symptoms or walking capacity were found, suggesting their multifactorial etiology.
authors: Department of Neurosurgery, Kuopio University Hospital, Kuopio, Finland. pekkaku@student.uef.fi.
authors: Pekka
authors: P
authors: Kuittinen
authors: Petri
authors: P
authors: Sipola
authors: Timo Juhani
authors: TJ
authors: Aalto
authors: Sara
authors: S
authors: Määttä
authors: Anita
authors: A
authors: Parviainen
authors: Tapani
authors: T
authors: Saari
authors: Sanna
authors: S
authors: Sinikallio
authors: Sakari
authors: S
authors: Savolainen
authors: Veli
authors: V
authors: Turunen
authors: Heikki
authors: H
authors: Kröger
authors: Olavi
authors: O
authors: Airaksinen
authors: Ville
authors: V
authors: Leinonen
mesh_terms: D000368:Aged; D004185:Disability Evaluation; D004576:Electromyography; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000209:etiology; D008159:Lumbar Vertebrae / Q000473:pathology* / Q000503:physiopathology* / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013130:Spinal Stenosis / Q000150:complications / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D016138:Walking