Clinical experience with paraspinal mapping. II: A simplified technique that eliminates three-fourths of needle insertions.
OBJECTIVE
To simplify and minimize the quantified needle examination of the paraspinal muscles (paraspinal mapping [PM]) without compromising sensitivity or specificity.


METHODS
Nonrandomized prospective trial.


METHODS
Electrodiagnostic laboratory of a university spine center and of a private practice in a small community.


METHODS
One hundred fourteen consecutive persons referred for electrodiagnosis of spinal or lower extremity disorders who had PM data and 35 previously reported asymptomatic volunteers.


METHODS
Abbreviated PM protocols were simulated by progressively eliminating data from the 45 needle insertions of the original PM. Simulations involving 35, 15, 13, and 5 insertions resulted in different normal values (95% of asymptomatic volunteers) and different scores in patients. The resulting reclassification of patients as normal or abnormal was compared with the original protocol and with clinical data.


METHODS
False positive and false negative rates of the simulations compared with the original protocol.


RESULTS
Abbreviated protocols involving 30, 15, 13, and 5 needle insertions had normal cutoff scores of less than 5, less than 4, less than 3, and less than 2, respectively, with 2%, 2%, 4%, and 8% false positive rates and 3%, 8%, 13%, and 21% false negative rates compared with the original. In many cases clinical information correlated better with the abbreviated test results than the original PM.


CONCLUSIONS
The third protocol compared well with the original PM, and in a limited number of patients with imaging studies demonstrated 92% sensitivity and 92% specificity. By eliminating the iliocostalis, longissimus, and lowest multifidus needle explorations, 73% fewer needle insertions were used. We recommend that this new technique, now called "miniPM," be used in most clinical settings.
Haig
A J
AJ
University of Michigan Spine Program 48109-0042, USA.
D004576:Electromyography / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D009339:Needles; D010808:Physical Examination; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013122:Spinal Diseases / Q000175:diagnosis* / Q000503:physiopathology; D014057:Tomography, X-Ray Computed