A closer look at subjective caloric sensations: Is there more to vertigo than spinning?

ABSTRACT

BACKGROUND: There is a prevailing opinion that spinning sensations signify a peripheral vestibular pathology while non-spinning sensations are not of vestibular origin. OBJECTIVES: 1) Characterize the subjective sensations reported by patients during caloric testing. 2) Assess if the sensation was correlated with the peak slow phase velocity (SPV). METHODS: Retrospective chart review at a Canadian adult tertiary-quaternary care balance centre for patients undergoing diagnostic caloric testing between December 2014 and September 2015. RESULTS: Of 163 patients included, 122 had normal calorics and 41 demonstrated unilateral weakness. Spinning/rotatory movements were the most commonly reported sensations (55-70%). No sensation was reported among 10-20% of patients. Other non-rotatory sensations were reported 20-25% of the time. Both lack of sensation and other sensations were more likely to be correlated with SPVs that were significantly lower than those associated with spinning/rotating sensations. However, 18% of patients with normal calorics and robust SPVs with warm irrigation still reported non-spinning sensations. CONCLUSIONS: During caloric irrigation, subjective sensations other than spinning and rotating are reported 20-25% of the time and these tend to be associated with lower peak SPV. Non-spinning vertigo is not uncommon as a subjective description of vestibular sensation even in normal patients with strong SPVs.