Reliability and diagnostic accuracy of clinical special tests for myelopathy in patients seen for cervical dysfunction.
METHODS
Case control study.


BACKGROUND
Myelopathy is a clinical diagnosis based largely on initial examination findings during a clinical screen, followed by imaging verification of cord injury or compression. At present, few studies have examined the reliability and diagnostic accuracy of clinical examination measures.


OBJECTIVE
To determine the reliability and diagnostic accuracy of neurological tests associated with the diagnosis of myelopathy.


METHODS
Reliability and diagnostic accuracy of 7 frequently used tests and measures and subjective findings associated with myelopathy were examined on consecutive patients with cervical pain. Interrater reliability and diagnostic accuracy values, including posttest probability, based on a pretest probability of 40%, were calculated for each test and for combinations of tests and measures.


RESULTS
Four of the 7 diagnostic tests were found to have a substantial interrater reliability. None of the single or clusters of tests yielded low negative likelihood ratios. Of the individual tests, the Babinski sign demonstrated the highest positive likelihood ratio (LR+, 4.0; 95% CI: 1.1-16.6) and posttest probability (73%) for diagnosis, but yielded only a moderate negative likelihood ratio (LR-, 0.7; 95% CI: 0.6-0.9). Combinations of tests did not yield improved accuracy values over single test results.


CONCLUSIONS
This study demonstrated that 4 of 7 tests used to screen for myelopathy offered substantial levels of interrater agreement when used on individuals with cervical dysfunction. None of the tests when performed individually or in combinations are effective for screening; however, the Babinski sign did alter posttest probability more significantly than combinations of test findings.


METHODS
Diagnosis, Level 2b.
Cook
Chad
C
Department of Surgery, Duke University, Durham, NC, USA. chad.cook@duke.edu
Roman
Matthew
M
Stewart
Kathleen M
KM
Leithe
Linda Gray
LG
Isaacs
Robert
R
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000175:diagnosis*; D010808:Physical Examination / Q000379:methods*; D015203:Reproducibility of Results; D013118:Spinal Cord Diseases / Q000175:diagnosis*