Electroneurography and electromyography for assessing the difference in euroelectrophysiological characteristics between patients with amyotrophic lateral sclerosis and those with cervical spondylotic myelopathy

Chunzhi WANG; Weijiang DING; Lijun XU

ABSTRACT

BACKGROUND:

The early symptoms of amyotrophic lateral sclerosis (ASL) are usually located at a certain part of the body, and are similar to the clinical manifestations of cervical spondylotic myelopathy (CSM). However, their treatment and prognosis differ greatly. Therefore, multiple-part electromyography and electroneurography possess an important value of reference, particularly electromyography of thoracic paraspinal muscles can be used as an objective parameter for differentiation between ASL and CSM.

OBJECTIVE:

To investigate the electrophysiological changes in ASL and CSM.

DESIGN:

A retrospective clinical analysis.

SETTING:

Neurological Department of Second Hospital Affiliated to Jiangxi Medical College.

PARTICIPANTS:

Totally 30 inpatients and outpatients with ASL and 30 patients with CSM were selected from the Neurological Department of the Second Hospital Affiliated to Jiangxi Medical College between December 2001 and November 2004.

METHODS:

Totally 30 inpatients and outpatients with ASL as well as 30 inpatients and outpatients with CSM were subjected to routine electromyographic and electroneurographic examination. Routine electromyography examining three limb muscles + sternocleidomastoid + thoracic paraspinal muscles intended to observe the spontaneous potential at resting stage, time limit and wave-amplitude of motor unit potential, and recruit-ment phase during energetic contraction. Electroneurography was used to detect motsr conduction velocity and sensory conduction velocity,as well as the terminal latency and wave-amplitude of motor evoked potential.limb muscles, sternocleidomastoid and thoracic paraspinal muscles in paASL and SCM.

RESULTS:

Data of all the 60 patients entered the final statistical analysis.in patients with ALS and CSM, and were more severe in the former. The abnormality rate of spontaneous potential of thoracic paraspinal muscles reached 93.3% (28/30) as compared to 3.3% (1/30) in patients with CSM (P ＜ 0.001). The average time limit and abnormal increment of wave amplitude of motor unit potential were significantly different in patients with conduction velocity The decrease rate of motor evoked potential amplitude of complex muscles was obviously higher in ASL than in CSM (75.6% and 86.7%, ~=7.25, P ＜ 0.01). So was the decrease rate of motor conduction sory nerve conduction velocity It was not affected either in ASL or CSM.ALS and CSM, but the abnormality rate of spontaneous potential of thorography indicates that nerve conduction velocity was not affected in both playing decreased conduction velocity and wave amplitude than those with CSM.