Evidence Update

This clinical commentary provides the scientific and clinical background to support arguments that sensorimotor deficits in the cervical spine have significant implications for postural stability and head and eye movement control. In addition, the authors review the relevant literature showing that significant sensorimotor cervical proprioceptive disturbances could play a significant role in the maintenance, recurrence, or progression of some of the other symptoms patients with neck pain complain about. They argue that these impairments must be addressed in order to provide a comprehensive rehabilitation program for these patients.

The paper begins with a description of the postural control system in general, and then specifically discusses the contributions of the cervical spine to postural control. The authors cite the relevant research demonstrating altered postural stability and eye and head control following artificial disturbances to cervical afferent input in healthy subjects, as well as in patients with neck pain. They then present the clinical research, clinical presentation, and clinical assessment of patients with disturbed head-neck awareness, disturbed neck movement control, disturbed postural stability (including patients complaining of dizziness and/or unsteadiness), and disturbances in oculomotor function. The paper concludes with suggestions on the clinical management of patients with these impairments. These suggestions include addressing altered cervical afferent input, secondary adaptive changes in the sensorimotor control system, intertwining manual therapy/exercise approaches with tailored sensor motor control programs, and specific exercises to address sensorimotor deficits. The paper concludes with suggestions for future research.

This paper does an excellent job of summarizing the relevant research on the implications of sensorimotor deficits in the cervical spine, and translating that research into practical suggestions. Furthermore, the authors make a strong argument that the evaluation and management of sensorimotor deficits must be an integral part of any cervical spine program, becoming as commonplace in the cervical spine as proprioceptive training is in treating patients with foot and ankle injuries. If you’re treating patients with cervical disorders, or patients with postural dysfunction and/or eye-head movement control issues, I highly recommend that you read this article.

For a summary of the article, click here.

Stapely PJ et al. Neck muscle fatigue and postural control in patients with whiplash injury. Clin Neurophys, 117(2006): 610-622.

The postulated cause of cervicogenic dizziness is a sensory mismatch between cervical somatosensation and vestibular and visual inputs about head position. Proprioceptive input from the neck muscles plays a significant role in the control of posture, and in the perception of body orientation in space. Muscle fatigue has been shown to modify the discharge of sensory receptors and affect proprioception. Recent studies have begun to suggest that neck muscle fatigue may contribute to increases in body sway. The authors of this study hypothesized that patients with cervical disorders would be more susceptible to cervical muscle fatigue, would manifest increased sway and would have a poorer subjective sense of equilibrium. Furthermore, they investigated whether physical therapy aimed at reducing muscle tension and improving muscle function would reduce dizziness and improve postural sway.

Cochrane Review: Effectiveness of the canalith repositioning maneuver (Epley) for BPPV.

Hilton M, Pinder D. The Epley (canalith repositioning) manoeuvre for benign paroxysmal positional vertigo. Cochrane Database of Systematic Reviews 2004, Issue 2. Art. No.: CD003162. DOI:10.1002/14651858.CD003162.pub2.

The Epley manoeuvre can help spinning and dizziness on moving the head (benign paroxysmal positional vertigo) in the short term but more research is needed.

Benign paroxysmal positional vertigo (BPPV) is caused by a rapid change in head movement. The person feels they or their surroundings are moving or rotating. Common causes are head trauma or ear infection. BPPV can be caused by debris in the semicircular canal of the ear that continues to move after the head has stopped moving. This causes a sensation of ongoing movement that conflicts with other sensory information. The review of trials found the Epley manoeuvre (four specific movements of the head and body designed to move the debris out the ear canal) is safe and effective. More research is needed.

Click Here to see the Review

This review looked at the effectiveness of vestibular rehabilitation (including medication, physical maneuvers and exercise regimes) in the adult, community dwelling population of people with symptomatic unilateral peripheral vestibular dysfunction. Included studies addressed the effectiveness of vestibular rehabilitation against control/sham interventions, non-vestibular rehabilitation interventions or other forms of vestibular rehabilitation. There is moderate to strong evidence that vestibular rehabilitation is a safe, effective management for unilateral peripheral vestibular dysfunction, based on a number of high quality randomised controlled trials. There is moderate evidence that vestibular rehabilitation provides a resolution of symptoms in the medium term. However there is evidence that for the specific diagnostic group of benign paroxysmal positional vertigo, physical (repositioning) manoeuvres are more effective in the short term than exercise based vestibular rehabilitation.

COMMENT: This recent (October 2007) review would be useful for those who wish to market vestibular rehabilitation to new referral sources, or to current sources as a reminder of the effectiveness of vestibular rehab for UPVD.

Click Here to see the Review on PubMed.

Thirlwall AS, Kundu S. Diuretics for the treatment of Ménière's disease or syndrome.  Cochrane Database Syst Rev. 2006 Jul 19;3:CD003599.

Diuretics (drugs which reduce fluid accumulation in the body) are commonly used in the management of the symptoms of vertigo, hearing loss, tinnitus or aural fullness in patients with Ménière's disease. 'Endolymphatic hydrops' is an increase in the pressure of the fluids in the chambers of the inner ear and is thought to be the underlying cause of Ménière's disease. Diuretics are believed to work by reducing the volume (and therefore also the pressure) of these fluids. The authors of this systematic review carried out an extensive search but could not identify any randomised controlled trials of sufficient quality to include in the review. There is no good evidence about the effect of diuretics on the symptoms of Ménière's disease and further research is needed.

COMMENT: The jury is still out, as more studies need to be done. My hunch is that there may be more than one form of Meniere's disease, since it appears that some patients benefit from some interventions (e.g. reduced salt intake and diuretics) while others do not. We simply are unable to tell a priori who will benefit from what. Therefore, when research is done on patients with Meniere's the sample is probably not homogenous and negative results wash out positive results, leaving us with equivocal findings.

Click Here to see the Review on PubMed.