Changes in imaging and mechanical characteristics of neck muscles in patients with cervical vertigo and their correlations with vertigo symptoms

English Keywords:Dizziness  Neck pain  Elastic modulus  Regression analysis  Muscle strength

English Abstract:

  【Abstract】 Objectives: To investigate the correlation between neck muscle dysfunction and vertigo severity in patients with cervical vertigo(CV) by comparing the oblique diameter, cross-sectional area(CSA), stiffness, strength of neck muscles, and cervical rotation range between CV patients and healthy individuals. Methods: From January 2019 to December 2020, 30 outpatients diagnosed with CV (aged 25-65) were enrolled as the patient group from the outpatient clinic of Beijing Bo′ai Hospital, China Rehabilitation Research Center, and 30 age-matched healthy volunteers were recruited as the control group. All participants underwent assessments including cervical MRI, real-time shear wave elastography(SWE), cervical rotation range of motion(ROM), and neck muscle strength testing. The patient group also completed the dizziness handicap inventory(DHI) and visual analog scale(VAS) to quantify vertigo severity. MRI measurements included oblique diameter of the suboccipital muscles(rectus capitis posterior minor, obliquus capitis inferior) and CSA of the anterior and posterior neck muscles(sternocleidomastoid, longus colli, splenius capitis, semispinalis capitis). SWE was used to assess the stiffness(elastic modulus) of the sternocleidomastoid, splenius capitis, semispinalis capitis, and obliquus capitis inferior muscles. Independent sample t-test was used for inter-group comparison, and Mann-Whitney U test was used for data that did not conform to a normal distribution. Indicators that showed significant inter-group differences were subsequently included in multiple linear regression and logistic regression analyses, with a significance level set at P<0.05. Results: There was no significant difference between sex, age and BMI between the two groups(P>0.05). The CSA of the right cervical longus colli muscle in the patient group was significantly smaller than that in the control group(z=2.262, P<0.05), and no significant differences were found in the CSA of the remaining muscles between the two groups. There were no significant differences in the oblique diameter of bilateral rectus capitis posterior minor and obliquus capitis inferior between the two groups(P>0.05). The stiffness of bilateral sternocleidomastoid in the patient group was significantly lower than that in the control group(tL=-2.543, tR=-3.549, P<0.05), the stiffness of bilateral obliquus capitis inferior(tL=2.755, zR=-3.838), left splenius capitis(t=2.071) and left semispinalis capitis(t=2.324) in the patient group was significantly higher than that in the control group(P<0.05), and the stiffness of right splenius capitis and right semispinalis capitis was not significantly different between the two groups(P>0.05). There was no significant difference in cervical rotation between the two groups(P>0.05). The strength of flexion(z=-3.550), extension(z= -4.785), lateral bending(zL=-5.258, zR=-5.060) and rotation(zL=-5.398, zR=-4.905) of cervical spine were significantly lower in the patient group than in the control group(P<0.05). Correlation and multiple linear regression analyses: There was a linear regression relationship between the DHI score and the stiffness of the right obliquus capitis inferior muscle(β=0.412) and the strength of the extension(β=-0.357). The VAS score, had a linear regression relationship with the strength of the extension(β=-0.371), the stiffness of the right obliquus capitis inferior muscle(β=0.373), and the stiffness of the right sternocleidomastoid muscle(β=-0.204). Logistic regression analysis showed the stiffness of the right inferior oblique muscle(OR=17.863) and the strength of flexion(OR=2.555) were the risk factors for CV, while the strength of extension(OR=0.244) was a protective factor. Conclusions: In CV patients, the stiffness decreases in the anterior neck muscles and increases in the posterior muscles(especially the suboccipital muscles). Neck muscle strength is significantly impaired in all directions, while muscle morphology and cervical rotation ROM remain largely unchanged. The severity of vertigo is correlated with the stiffness of the right obliquus capitis inferior and posterior extension strength.