Aj. Haig, CLINICAL-EXPERIENCE WITH PARASPINAL MAPPING .1. NEUROPHYSIOLOGY OF THE PARASPINAL MUSCLES IN VARIOUS SPINAL-DISORDERS, Archives of physical medicine and rehabilitation, 78(11), 1997, pp. 1177-1184
Objective: To assess the extent of denervation of the paraspinal muscl
es in spinal disorders. Design: Nonrandomized prospective trial. Setti
ng: Electrodiagnostic laboratory of a university spine center and of a
private practice in a small community. Subjects: One hundred fourteen
consecutive persons referred for electrodiagnosis of spinal or lower
extremity disorders. Intervention: The paraspinal mapping (PM) electro
myography (EMG) protocol along with codified history, physical examina
tion, extremity EMG, and in 44 cases, radiologic imaging results. Main
Outcome Measures: PM scores compared with recently established norms
(95% of normal subjects scoring less than <6), lower extremity (LE) EM
G findings, and imaging results. Results: Fifty-eight subjects had nor
mal PM scores; 62 were abnormal. Compared to imaging studies, false po
sitive rate was 8% (1/13). False negative rate (normal PM with definit
e nerve involvement on imaging) was 33% (6/18), but this decreased to
5% when PM was combined with LE EMG. Four of 4 high lumbar lesions wer
e detected by PM. Of 14 apparent false negatives (13%) compared to LE
EMG, 6 had S1 root lesions and 5 had nonspinal lesions. All 7 subjects
with isolated S1 radiculopathy had PM scores within normal limits. Oc
casional polyneuropathies presented with normal PM and abnormal distal
findings or with abnormal PM but normal distal findings. No patient w
ith isolated paraspinal findings had evidence of malignancy on follow-
up. This report also describes the distribution of denervation in the
multifidus, longissimus, and iliocostalis in various disorders. Conclu
sions: PM relates well to imaging studies and LE EMG. It detects uncom
mon high lumbar root lesions. S1 may not innervate the paraspinal musc
les. There are isolated paraspinal findings in persons without maligna
ncy. The effects of specific muscle denervation on biomechanics, rehab
ilitation exercise, and prognosis are not known. (C) 1997 by the Ameri
can Congress of Rehabilitation Rehabilitation Medicine and the America
n Academy of Physical Medicine and Rehabilitation.