Visuo-proprioceptive interactions in degenerative cervical spine diseases requiring surgery

Abstract

Cervical proprioception plays a key role in postural control, but its specific contribution is controversial. Postural impairment was shown in whiplash injuries without demonstrating the sole involvement of the cervical spine. The consequences of degenerative cervical spine diseases are underreported in posture-related scientific literature in spite of their high prevalence. No report has focused on the two different mechanisms underlying cervicobrachial pain: herniated discs and spondylosis. This study aimed to evaluate postural control of two groups of patients with degenerative cervical spine diseases with or without optokinetic stimulation before and after surgical treatment. Seventeen patients with radiculopathy were recruited and divided into two groups according to the spondylotic or discal origin of the nerve compression. All patients and a control population of 31 healthy individuals underwent a static posturographic test with 12 recordings; the first four recordings with the head in 0° position: eyes closed, eyes open without optokinetic stimulation, with clockwise and counter clockwise optokinetic stimulations. These four sensorial situations were repeated with the head rotated 30° to the left and to the right. Patients repeated these 12 recordings 6weeks postoperatively. None of the patients reported vertigo or balance disorders before or after surgery. Prior to surgery, in the eyes closed condition, the herniated disc group was more stable than the spondylosis group. After surgery, the contribution of visual input to postural control in a dynamic visual environment was reduced in both cervical spine diseases whereas in a stable visual environment visual contribution was reduced only in the spondylosis group. The relative importance of visual and proprioceptive inputs to postural control varies according to the type of pathology and surgery tends to reduce visual contribution mostly in the spondylosis group.

Cervicogenic causes of vertigo

“…Li et al [21] also reported good results following more extensive cervical surgery. Freppel et al [4] KEY POINTS Cervicogenic vertigo/dizziness is probably common, but it lacks a validated clinical test.…”

“…This is logical as injuries to the neck might disturb the difficult adjustment between the two coordinate systems of the head and body [36]. Freppel et al [4] reported that the contribution of visual input to postural control was reduced in patients operated on for degenerative cervical spine disorders. Freppel et al [4] reported that the contribution of visual input to postural control was reduced in patients operated on for degenerative cervical spine disorders.…”

“Cervical Vertigo-Pathophysiology and Management: An Update”

“…A convincing mechanism of cervical vertigo is based on altered upper cervical somatosensory input associated with neck ten-derness and limitation of movement (7,13). Interstitial inflammatory mediators have been postulated to sensitize muscle spindles (37), and myofascial trigger points exhibit spontaneous electromyogram activity, which is compatible with hyperactive muscle spindles (38). Neck proprioception has been studied previously in patients with cervical vertigo as individuals with whiplashassociated unsteadiness and/or dizziness were shown to have significantly greater joint position errors and more severe neck pain than control subjects (27).…”

Response to Cervical Medial Branch Blocks In Patients with Cervicogenic Vertigo

“…Short-term benzodiazepines or antidepressants may improve emotional symptoms (1). Some studies report excellent outcomes after cervical spine surgery (5,22,23). However, it remains unreasonable to perform cervical spine surgery for CV lacking other indications for surgery.…”

“…Among the various causes of vertigo, the so-called cervicogenic vertigo (CV) has been the most controversial (1). However, there is clear experimental and clinical evidence that neck perturbations or purely proprioceptive signals can induce vertigo and imbalance (1,(3)(4)(5). Different pathophysiological mechanisms have been attributed (1) and many definitions are given for CV, some of which require pain and others that do not (6).…”