Introduction

Cervicogenic dizziness is a syndrome thought to occur due to a disturbance in the convergence of the proprioception of the neck and the vestibular system. The neck is very closely related to the occurrence of dizziness symptoms. Often neck pain precedes the dizziness onset and when the neck pain worsens, so does the dizziness. Drugs are often prescribed, but physiotherapy and manual therapy are also indicated to relieve neck symptoms. This randomized controlled trial aimed to examine the benefits of a strength training program, mobilization, and oculomotor exercises to address cervical and dizziness symptoms. So, what is the efficacy of self-exercise for cervicogenic dizziness? Let’s dive in!

Methods

The randomized controlled trial was set up in a department of otorhinolaryngology from 2018 to 2020. Patients from the age of 18 with non-traumatic cervicogenic dizziness were included. The diagnosis was made from patient history revealing a history of neck pathology and dizziness in close temporal relationship with the onset of cervical spine symptoms. The patients were screened for trauma, cervical arterial dysfunction, and neurological pathologies and excluded if one of those was positive. A vestibular assessment was performed to exclude other pathologies leading to dizziness. Then the authors report having conducted a careful spine examination to identify the source of pain.

The patients got a program to self-exercise for cervicogenic dizziness. The self-exercise program consisted of the following:

• Strength exercise: Ten times 5-second isometric contractions in the direction of flexion, extension, rotation, and lateral flexion.
• Mobilization exercise: Ten times movements in the direction of flexion, extension, rotation, and lateral flexion, holding the end position for 5 seconds
• Oculomotor training is described as follows:
  • Flexion: Set a fixed point in front of the eyes by holding out the arm and looking at the thumb. Try to touch the chest with the chin while keeping the eyes on the thumb for 5 s × 10 times.
  • Extension: Set a fixed point in front of the eyes by holding out the arm and looking at the thumb. Slowly move the head backward and look upward while keeping the eyes on the thumb for 5 s × 10 times.
  • Rotation: Set a fixed point in front of the eyes by holding out the arm and looking at the thumb. Turn the head to the right and left making a stop in the middle of the range while keeping the eyes on the thumb for 5 s × 10 times.
  • Lateral flexion: Set a fixed point in front of the eyes by holding out the arm and looking at the thumb. Tilt the head to the right and the left, making a stop in the middle of the range, while keeping the eyes on the thumb for 5 s × 10 times.

Both the intervention group performing self-exercises for cervicogenic dizziness and the control group were advised to take 50mg dimenhydrinate when they had severe vertigo every 8 hours and 400mg ibuprofen to reduce cervical pain. They were advised to stop taking it when symptoms improved. The control group did not receive any exercise program.

The assessed outcomes were the Dizziness Handicap Inventory (DHI) questionnaire which measures the perceived handicapping effect of dizziness symptoms. This scale has 25 items and the scores range from 16-34, 36-52, and 54 points or more, meaning mild, moderate, and severe dizziness handicaps. The Neck Disability Index (NDI) questionnaire measures neck disability and consists of 10 items. The maximal score is 50 which indicates high disability. Further, the VAS scale for neck pain was filled and the range of motion was assessed. The authors defined a full active range of motion of the neck as follows: flexion more than 50°, extension more than 60°, lateral flexion more than 45° and rotation more than 80°. Posturography was included as an objective measure to assess functional balance and the relative contributions of the visual, proprioception, and vestibular cues.

The patients were followed for 2 weeks.

Results

A total of 32 participants with cervicogenic dizziness were included in the RCT. They were equally divided into the self-exercise for cervicogenic dizziness and control groups. In both groups, 3 patients were lost to follow-up.

The average age of the sample was 48 years, and most of them were female. The baseline characteristics did not reveal significant differences in sex, age, duration of vertigo, and the presence of underlying diseases.

After two weeks of participating in the self-exercise for cervicogenic dizziness or control intervention, results indicated that the DHI was significantly lower in the intervention group. The mean difference was 25 points on average (95% CI 4.21 to 47.63), meaning lower handicapping effects of dizziness. The same results were seen for the NDI, where a mean difference of 6.16 (95% CI 0.42 to 11.88) was observed in favor of the self-exercise group. Only the difference on the DHI can be seen as clinically relevant as it exceeds the minimal detectable change of 17 points. No significant differences were found in VAS pain or in sway velocity as objectified during posturography.

Questions and thoughts

There were no significant differences in baseline characteristics, although the duration of dizziness days in the self-exercise group seems to be almost double that of the controls.

The authors report having conducted a careful spine examination to identify the source of pain. However, determining the source of symptoms is difficult based on palpation and motion assessment. Most likely they identified the location of pain, instead of the source of pain.

The self-exercise for cervicogenic dizziness included strength exercises. However, as there was no added resistance, and the contractions had to be sustained for 5 seconds, these exercises are merely isometric strength exercises.

The NDI and DHI improved, but so didn’t the VAS score for pain. This is remarkable, to say the least, as cervicogenic headache is thought to result from a mismatch of information coming from the neck proprioception and the other contributing systems (visual, somatosensory, and vestibular). This way, it appears that this sample of participants may not have had “true” cervicogenic dizziness, or maybe possibly even more controversial, the existence of cervicogenic dizziness may be questioned…

Talk nerdy to me

The DHI was administered at baseline and after 2 weeks of performing the self-exercise for cervicogenic dizziness. However, the authors asked the participants to answer each question as it pertains to dizziness or unsteadiness problems, specifically considering their condition

during the last month. This not only leaves open the possibility of recall bias, but certainly does not seem logical given that the trial lasted only 2 weeks.

The range of motion results reveal that there were no significant differences. Note that the authors haven’t specified their outcome of interest (primary outcome) and did not refer to a published trial protocol, which makes selective reporting possible. Furthermore, I find it odd that the range of motion (a continuous value) is dichotomized into a “yes/no” response. Especially when there is no further reporting of the true continuous range of motion values. When looking back at the definition of a limited range of motion, for example in rotation, was below 80°. Dichotomizing this value means that someone with, let’s say 79° of rotation range of motion is classified as someone whose neck mobility did not improve. You may start to understand why this can lead to selective reporting. Yet, no significant differences between the self-exercise group and the control group were reported, so we may be a little more confident that selective reporting bias did not occur here.

This trial was a classic example of an A (control: use of rescue medications) versus A+B (intervention: use of rescue medications + self-exercises) trial. It can be expected that more interventions administered usually give better outcomes in this group. It is also important to mention that before someone enters a trial, he is informed about the study procedures before he is randomized. Thus, the participants who took medications and performed exercises could likely have imagined they were part of the intervention group. As there was no reporting of blinding of the patients and assessors, this leaves us with more doubts.

Sample size calculations were done, but didn’t specify many details, for example on the exact outcome it was based upon. The short follow-up period, the possible selective reporting, and the relatively high number of participants lost to follow-up are important limitations to bear in mind.

Take home messages

This RCT showed that the invalidating aspects of cervicogenic dizziness improve after 2 weeks of performing self-exercises. Some aspects may limitate the validity of these findings, for example the lack of blinding and the absence of a predetermined primary outcome. Nonetheless, the strength of this trial is the application of self-exercise for cervicogenic dizziness in a very easy way, with no equipment required.

Reference

Piromchai P, Toumjaidee N, Srirompotong S, Yimtae K. The efficacy of self-exercise in a patient with cervicogenic dizziness: A randomized controlled trial. Front Neurol. 2023 Feb 14;14:1121101. doi: 10.3389/fneur.2023.1121101. PMID: 36864911; PMCID: PMC9972221.