Pf. Beattie et al., Associations between patient report of symptoms and anatomic impairment visible on lumbar magnetic resonance imaging, SPINE, 25(7), 2000, pp. 819-828
Study Design. A cross-sectional study comparing the relationship of symptom
s with anatomic impairment visible on lumbar magnetic resonance imaging in
408 symptomatic subjects.
Objective. To determine how various anatomic impairments, including the mag
nitude and location of nerve compression visible on lumbar magnetic resonan
ce imaging, are associated with patient reports of pain, weakness, and dyse
sthesia.
Summary and Background Data. Anatomic impairments of the intervertebral dis
c, radicular canal, and associated soft tissues are prevalent in people wit
h and those without low back pain or lower extremity radiculopathy. This ha
s led to confusion in differentiating between symptom generators and benign
variation visible on lumbar magnetic resonance imaging. Recent literature
has suggested that the presence of nerve compression is an important findin
g in the prediction of symptoms. However, the threshold for meaningful nerv
e compression has not been described.
Methods. In this study, 408 participants undergoing a diagnostic workup for
low back pain, radiculopathy, and/ or completed a survey and pain drawing.
Participants underwent standardized lumbar magnetic resonance imaging usin
g a 1.5-T scanner. Two classification systems describing the spatial distri
bution of symptoms were developed. An additional system to quantify the mag
nitude of nerve and thecal sac compression was created. All systems were as
sessed for reliability, after which comparisons among variables were perfor
med using X-2 as well as simple and multiple logistic regression analysis.
Results. The reliability coefficients for categorizing patients on the basi
s of pain drawing ranged from 0.75 to 0.88. The S1-S2 segmental distributio
n was the most commonly reported location of symptoms, followed by L4-L5, T
he most common magnetic resonance imaging diagnosis was "unremarkable," fol
lowed by "disc impairment without nerve compression." Disc extrusion was pr
esent in 10.8% of participants. The reliability of classifying nerve compre
ssion visible on magnetic resonance imaging ranged from 0.27 to 1. Nerve co
mpression was present in 37% of participants, and 18% had severe nerve comp
ression. There were no significant associations between segmental distribut
ion of symptoms and the presence of anatomic impairment. However, according
to a collapsed classification scale, severe nerve compression and disc ext
rusion were predictive of pain distal to the knee (odds ratios, 2.72 and 3.
34). The self-report of weakness was associated mildly with severe nerve co
mpression and disc extrusion, but not with other findings. Magnetic resonan
ce imaging findings did not predict self-reports of dysesthesia.
Conclusions. The presence of disc extrusion and/or ipsilateral, severe nerv
e compression at one or multiple sites is strongly associated with distal l
eg pain. Mild to moderate nerve compression, disc degeneration or bulging,
and central spinal stenosis are not significantly associated with specific
pain patterns. Although segmental distributions of pain can be determined r
eliably from pain drawings, this finding alone is of little use in predicti
ng lumbar impairment. The self-report of lower extremity weakness or dysest
hesia is not significantly related to any specific lumbar impairments.