The Status of Cervical Vestibular Evoked Myogenic Potentials in Patients with Cervical Discopathy and Different Types of Vertigo
Objective: This research study aims to assess the status of cervical vestibular evoked myogenic potentials (cVEMP) in patients diagnosed with cervical discopathy and experiencing different types of vertigo. Cervical discopathy is a common condition characterized by disc degeneration and herniation in the cervical spine. Vertigo, a symptom of vestibular dysfunction, can be caused by various factors including cervical discopathy. However, the relationship between cervical discopathy and different types of vertigo remains unclear.
Design:
The study will recruit a sample of patients diagnosed with cervical discopathy, and presenting with different types of vertigo. The cVEMP test will be conducted to evaluate the vestibular function specifically related to the cervical disc status. The cVEMP test involves measuring the muscular responses of the sternocleidomastoid muscle in response to auditory stimuli.
Result: The primary outcomes of this study include the assessment of cVEMP parameters such as peak-to-peak amplitudes and latencies in patients with cervical discopathy and various types of vertigo. These parameters will be compared with a control group of individuals without cervical discopathy or vertigo. Additionally, the study will explore potential correlations between cVEMP findings and clinical symptoms and characteristics related to cervical discopathy.
Conclusion: The results of this research will provide valuable insights into the vestibular function associated with cervical discopathy and different types of vertigo. The findings may contribute to the understanding of the pathophysiology of vertigo in patients with cervical discopathy and help develop targeted management strategies. Ultimately, this study aims to improve the diagnosis and treatment of patients experiencing vertigo associated with cervical spine disorders.
Keywords: cervical vestibular evoked myogenic potentials, cVEMP, cervical discopathy, vertigo, vestibular dysfunction
Key points
Introduction
Cervical spondylosis and cervical disc herniation are highly prevalent degenerative diseases affecting the cervical spine. In certain instances, they can lead to myelopathy, thereby elevating the potential for significant disability. Key manifestations of these conditions encompass neck pain, stiffness, radiculopathy, and symptoms specific to the affected segment of the spinal cord. 1
Cervical vestibular evoked myogenic potentials (cVEMP) provide an objective approach to extracting information about the vestibular portion of the inner ear through the stimulation of the sternocleidomastoid muscle. cVEMPis elicited by delivering alternating 500 Hz tone bursts via air conduction and is directly recorded from the sternocleidomastoid muscle mechanoreceptors.2 This response originates from a reflex circuit that begins in the saccule and proceeds to the ipsilateral vestibular nuclei, ultimately reaching the ipsilateral spinal accessory nerve nuclei.3Abundant manuscripts could be found about cervical vertigo and cervical disc pathologies.4,5 On the other hand the effect of cervical disc pathologies on cVEMP in patients that have noncervical vertigo remains scarce.
The aim of this present study is to investigate the prevalence and the types of peripheral vertigo in patients with cervical hernia and to consider the difference in the cVEMP results of the vertigo patients according to cervical disc status
Material and Methods
Subjects
Between January 2021 and July 2022 thirty-three patients with different diagnoses of peripheral vertigo enrolled in this study. Written informed consent was obtained from the patients. The study design and reporting followed the guidelines set forth by the EQUATOR network for prospective studies.
After taking medical records, all patients with vertiginous symptoms underwent detailed ear nose and throat physical examination. The most common peripheral vertigo diagnosis were; benign paroxysmal positional vertigo (BPPV), vestibular migraine, semicircular canal dehishence syndrome . Benign paroxysmal positional vertigo diagnosed with head thrust, rotating chair and dix-hallpike tests. Vestibular migraine diagnosis was by the criteria of at least five episodes with vestibular symptoms of moderate or severe intensity, lasting five minutes to seventy-five hours, current or previous history of migraine, and one or more migraine features with at least 50% of the vestibular episodes.6 Semicircular canal dehiscence syndrome was diagnosed with thin slice petrous temporal tomography in the patients with complaints of hearing loss, vertigo and/ or pulsatile tinnitus.
All the patients were checked for the pain that radiates through the ear, neck, arm and shoulder with a gait and imbalance and the numbness of the shoulder and arm. Any of the mentioned complaints were recorded when the patient underwent a cervical MRI.
The cervical VEMP (cVEMP) procedure was started with skin preparation by using an alcohol swap. Three electrodes (active, reference and ground) were placed. The active surface electrode was placed at the skin, approximately to the sternocleidomastoid muscle middle part. The upper sternum was the reference electrode location. The forehead was the ground electrode location.
The unilateral air conducted alternating 500 Hz tone bursts was applied by using ER3A-insert earphones. (Etymotic Research, Elk Grove Village, IL, USA.) The initial stimulus intensity was 85 dBnHL and increased incrementally to 95 dBnHL and 105 dBnHL. Electromyography signals were identified, amplified (5000X), filtered (Blackman gating function bandpass 10-1500 Hz) and recorded. The calculation of the interaural difference (IAD) ratio was made by dividing the inter-ear difference of p1-n1 interamplitude by the sum of the p1-n1 interamplitude of both ears. (7,8)
Statistical Analysis
Statistical analysis made by STATA SE 17 software (Copyright 1985-2021 StataCorp LLC StataCorp 4905 Lakeway Drive College Station, Texas 77845 USA). Mean±standard deviation is the expression of continuous data. Non-normal data were converted into logarithmic form and compared with the Mann-Whitney U test. The comparison of variables was performed by the independent student T-Test, p values under <0,05 considered statistically significant. This study has been approved by Local Committee of Ethics at the University XXX.
Conflict of Interest : None
Results
33 patients 20 female, 13 male. Age 51.51 ±15.67 (min 21- max 85) Most common peripheric vertigo etiology left benign paroxysmal positional vertigo (bppv), right bbpv and migratuar vertigo. (Table 1)
Table 1: The distribution of different types of peripheral vertigo among the study population