Lightning Podiums: Cervical Degenerative - Room 802A

Presented by: K. Ju

Author(s):

R. Haddas(1), A. Boah(2), K. Ju(3)

(1) Texas Back Institute, Research Foundation, Plano, TX, United States
(2) Texas Back Institute, Denton, TX, United States
(3) Texas Back Institute, Rockwall, TX, United States

Abstract

Objective: To compare spine and lower extremity neuromuscular activity in patients with CSM before and after surgical intervention.

Background: Cervical spondylotic myelopathy (CSM) is a degenerative condition of the cervical spine leading to a spectrum of neurological dysfunction. Gait impairment is one hallmark of CSM and has been shown to affect quality of life and ability to work, and has been reported to be improved by surgical intervention. Currently, the gait disturbance in CSM is poorly understood. Some studies describe the gait as spastic, while others suggest a paretic component. Further EMG characterization of the gait cycle may help elucidate the true neuromuscular pathology with implications on patient prognosis and rehabilitation techniques.

Patient Sample: Twelve patients with symptomatic CSM who underwent surgical intervention for their myelopathy.

Outcome Measures: Spine and lower extremity of integrated electromyography (iEMG, mV). iEMG activity is a graphic representation of the sum total EMG activity over a defined period of time. Muscle onset was measured as percentage of the gait cycle (GC, 0 % equal to heel contact).

Methods: Clinical gait analysis was performed the week before surgery (Pre) and 3 months after surgery (Post). Medial Deltoid (MD), External Oblique (EO), Multifidus (Mf) at the level of L5, Erector Spinae (ES) at the level of L1, Rectus Femoris (RF), Semitendinosus (ST), Tibialis Anterior (TA), and Medial Gastrocnemius (MG) neuromuscular activity were measured and recorded during the gait analysis session. Each subject performed a series of over-ground gait trials at a comfortable, self-selected walking speed. Repeated measurements ANOVA analysis was used to determine difference in neuromuscular control during gait in CSM patients before and after surgical intervention.

Results: Surgical intervention significantly reduced activation of the MD (Pre: 0.95±0.01 vs Post: 0.48±0.01 mV; p=0.049), ES (Pre: 1.57±1.8 vs Post: 0.40±0.3 mV; p=0.038), and ST (Pre: 4.50±4.4 vs Post: 1.64±1.3 mV; p=0.029) in patients with CSM. Muscle onset was significantly earlier in CSM patients before surgery after surgery in the EO (Pre: 1.91±1.1 vs Post: 3.80±0.6 % GC; p=0.043), MD (Pre: 2.11±1.1 vs Post: 4.27±0.6 % GC; p=0.042), Mf (Pre: 2.23±1.1 vs Post: 3.91±0.7 % GC; p=0.035), ES (Pre: 1.18±1.0 vs Post: 3.96±0.7 % GC; p=0.011), RF (Pre: 3.01±1.0 vs Post: 4.26±0.7 % GC; p=0.048), ST (Pre: 0.50±1.1 vs Post: 3.81±0.7 % GC; p=0.009), TA (Pre: 2.05±0.9 vs Post: 3.99±0.8 % GC; p=0.035), and MG (Pre: 2.36±1.0 vs Post: 3.93±0.8 % GC; p=0.050) muscles.

Conclusions: Patients with CSM often present with gait disturbance, which has a significant impact on one's quality of life but unfortunately is poorly understood. Preoperatively, CSM patients demonstrated over-activation of the MD, ES, and ST muscles. However, after cervical decompression surgery, the abnormal activity in these muscles was reduced to more normal levels. Furthermore, prior to surgery, CSM patients exhibited abnormally early activation of several muscle during gait, and, in some individuals, these muscle groups were continuously contracting throughout the entire gait cycle. However, following surgery, the timing of when each of the muscles became activated were more normal, allowing for a more fluid and coordinated gait pattern.