Friday, September 28, 2018 4:05 PM–5:05 PM abstracts: cervical myelopathy and deformity: 255. Neuromuscular activity during gait in patients with cervical spondylotic myelopathy

BACKGROUND CONTEXT Gait impairment is a hallmark of cervical spondylotic myelopathy (CSM) and has been shown to affect quality of life. Some studies describe the gait as spastic, while others suggest a paretic component. Further electromyographic (EMG) characterization of the gait cycle may help elucidate the true neuromuscular pathology with implications on prognosis and rehabilitation techniques. PURPOSE To compareneuromuscular activity in CSM patients to healthy, age-matched controls. STUDY DESIGN/SETTING Nonrandomized, prospective, concurrent control cohort study. PATIENT SAMPLE Forty patients with symptomatic CSM prior to any surgical intervention and 25 healthy controls. OUTCOME MEASURES Integrated electromyography (iEMG), peak EMG, time to peak EMG, mean power frequency and time of muscle onset. METHODS Forty patients with symptomatic CSM prior to any surgical intervention and 25 healthy controls had neuromuscular activity measured during a series of over-ground gait trials at a self-selected speed. External Oblique (EO), Multifidus (Mf), Erector Spinae (ES), Rectus Femoris (RF), Semitendinosus (ST), Tibialis Anterior (TA), Medial Gastrocnemius (MG) and Medial Deltoid (MD) were assessed. Differences in integrated electromyography (iEMG), peak EMG, time to peak EMG, mean power frequency and time of muscle onset were assessed using one-way ANOVA. RESULTS Compared to controls, patients with CSM demonstrated significantly less activation amplitude of the EO (0.72±0.79 vs. 1.52±2.05mV; p=.034), ST (3.02±5.37 vs. 5.86±9.19mV; p=.05), and MD (0.876±0.81 vs. 2.6±3.77mV; p=.008). They demonstrated significantly higher peak EMG muscle activity in the MD (0.06±0.044 vs. 0.03±0.021mV; p=.031) and significantly longer time to peak EMG muscle activity in the Mf (20.2±8.5 vs. 16.8±8.9ms, p=0.050), ES (18.2±6.7 vs. 8.9±7.2ms; p CONCLUSIONS Patients with CSM often present with a gait disturbance that has significant implications on quality of life. This study's findings demonstrate difficulty with muscular recruitment in lower extremity stabilizing musculature, coupled with increased peak EMG activity in the MD, representing compensatory mechanisms in the upper extremities, as well. This study contributes to existing knowledge on EMG muscle activity in patients with untreated CSM and will be useful in future studies investigating neuromuscular function in patients with CSM after surgical decompression.