| Summary: | Cervical vestibular evoked myogenic potential (cVEMP) testing is widely used in the
assessment of vestibular disorders in clinical practice (Welgampola & Colebatch, 2003).
Ocular vestibular evoked myogenic potentials (oVEMPs) are similar to the cervical VEMPs in
that the vestibular system is also stimulated by a loud sound. The difference is that the
response is measured on the inferior oblique muscle of the eye as opposed to the
sternocleidomastoid muscle (SCM) of the neck (Chihara, Iwasaki, Ushio, & Murofushi,
2007). The current study compares the standard cervical VEMP to the ocular VEMP in both
control subjects and participants with “clinically certain” Ménière’s disease. By investigating
cervical VEMPs in comparison to ocular VEMPs we aimed to improve the ability to stage and
diagnose Ménière’s disease using the ocular VEMP.
22 control participants and 19 participants with confirmed unilateral Ménière’s disease
took part in the study. The peak latency and amplitudes of the ocular and cervical VEMP tests
were recorded and analysed. In addition, the background electromyographic (EMG) activity
of both the inferior oblique and sternocleidomastoid muscles was recorded throughout testing.
A questionnaire was also distributed to all participants to compare the relative difficulty of the
VEMP tests. Statistical analysis using the paired t-test, standard t-test and the one-way
ANOVA on ranks test was applied to determine a difference between the control and patient
groups for both the ocular and cervical VEMP tests.
Overall, the threshold and IAD ratio measures did not produce any significant results
when sound was presented to the affected ear for the cervical and ocular VEMP tests. A
significant reduction in amplitude of the VEMPs from the Ménière’s groups was found
compared to the control groups for the ocular the cervical VEMPs. Overall, an increase in P2
and N3 latency of the ocular VEMP response in Ménière’s patients was determined. Results
from the questionnaire suggest that the ocular VEMP test was more tolerable to the cervical
VEMP test in this current study. Furthermore, statistical analyses revealed no significant
differences in EMG level between the control and Ménière’s group for both the ocular and
cervical VEMP data.
Overall, results suggest that both the cervical and ocular VEMP tests provide information
regarding the integrity of the saccule, owing to the abnormal VEMP findings in the
participants with Ménière’s disease. In addition, this study provides evidence that the ocular
VEMP is as useful a tool in diagnosing Ménière’s disease as the cervical VEMP.
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