title: The reliability of differentiating neurogenic claudication from vascular claudication based on symptomatic presentation.
abstract: BACKGROUND
  Intermittent claudication can be neurogenic or vascular. Physicians use a profile based on symptom attributes to differentiate the 2 types of claudication, and this guides their investigations for diagnosis of the underlying pathology. We evaluated the validity of these symptom attributes in differentiating neurogenic from vascular claudication.
  
  
  METHODS
  Patients with a diagnosis of lumbar spinal stenosis (LSS) or peripheral vascular disease (PVD) who reported claudication answered 14 questions characterizing their symptoms. We determined the sensitivity, specificity and positive and negative likelihood ratios (PLR and NLR) for neurogenic and vascular claudication for each symptom attribute.
  
  
  RESULTS
  We studied 53 patients. The most sensitive symptom attribute to rule out LSS was the absence of "triggering of pain with standing alone" (sensitivity 0.97, NLR 0.050). Pain alleviators and symptom location data showed a weak clinical significance for LSS and PVD. Constellation of symptoms yielded the strongest associations: patients with a positive shopping cart sign whose symptoms were located above the knees, triggered with standing alone and relieved with sitting had a strong likelihood of neurogenic claudication (PLR 13). Patients with symptoms in the calf that were relieved with standing alone had a strong likelihood of vascular claudication (PLR 20.0).
  
  
  CONCLUSIONS
  The classic symptom attributes used to differentiate neurogenic from vascular claudication are at best weakly valid independently. However, certain constellation of symptoms are much more indicative of etiology. These results can guide general practitioners in their evaluation of and investigation for claudication.
authors.affiliation: The Division of Orthopaedics, Department of Surgery, The University of Western Ontario, London, Ont.
authors.forename: Mélissa
authors.initials: M
authors.lastname: Nadeau
authors.forename: M Patricia
authors.initials: MP
authors.lastname: Rosas-Arellano
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Gurr
authors.forename: Stewart I
authors.initials: SI
authors.lastname: Bailey
authors.forename: David C
authors.initials: DC
authors.lastname: Taylor
authors.forename: Ruby
authors.initials: R
authors.lastname: Grewal
authors.forename: D Kirk
authors.initials: DK
authors.lastname: Lawlor
authors.forename: Chris S
authors.initials: CS
authors.lastname: Bailey
mesh_terms: D000368:Aged; D015331:Cohort Studies; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007383:Intermittent Claudication / Q000175:diagnosis* / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000150:complications*; D011446:Prospective Studies; D015203:Reproducibility of Results; D014652:Vascular Diseases / Q000150:complications*