Clinical diagnoses of patients showing caloric inversion.

OBJECTIVES: When air irrigation is used for caloric stimulation in patients with a perforated ear, warm irrigation may elicit a nystagmus that initially beats in the opposite direction of what is expected for warm irrigations, which is referred to as "caloric inversion". This study aimed to investigate the disease group in which caloric inversion appeared in patients who underwent caloric testing and to classify the patterns of caloric inversion. METHODS: We conducted a retrospective review of bithermal caloric test results that were collected in our dizziness clinic between 2005 and 2022. Caloric inversion was defined when nystagmus induced by caloric stimulation appeared in the opposite direction to that expected. The incidence of caloric inversion among all patients who underwent bithermal caloric tests was calculated. To confirm the clinical diagnoses of the patients with caloric inversion, their clinical records were reviewed. RESULTS: Out of 9923 patients who underwent bithermal caloric tests, 29 patients (0.29%) showed a caloric inversion. The most common clinical diagnosis was chronic otitis media (21 of 29, 72%). Of the 21 patients with chronic otitis media, 20 patients showed a caloric inversion by warm air irrigation and one patient showed caloric inversion by cold air stimulation. Patients with clinical diagnoses other than chronic otitis media such as sudden sensorineural hearing loss, benign paroxysmal vertigo of childhood and recurrent vestibulopathy showed caloric inversion by warm air irrigation. Caloric inversion by warm water irrigation was observed in patients with lateral semicircular canal cupulopathy and recurrent vestibulopathy. Two patients (one with Meniere's disease and one with age-related dizziness) showed caloric inversion by cold water irrigation. CONCLUSION: Caloric inversion can be observed in various diseases other than chronic otitis media with tympanic membrane perforation. Special care should be taken in the interpretation of caloric test results. LEVEL OF EVIDENCE: Level 4.

Clinical diagnoses of patients showing caloric inversion

Abstract Objectives When air irrigation is used for caloric stimulation in patients with a perforated ear, warm irrigation may elicit a nystagmus that initially beats in the opposite direction of what is expected for warm irrigations, which is referred to as "caloric inversion". This study aimed to investigate the disease group in which caloric inversion appeared in patients who underwent caloric testing and to classify the patterns of caloric inversion. Methods We conducted a retrospective review of bithermal caloric test results that were collected in our dizziness clinic between 2005 and 2022. Caloric inversion was defined when nystagmus induced by caloric stimulation appeared in the opposite direction to that expected. The incidence of caloric inversion among all patients who underwent bithermal caloric tests was calculated. To confirm the clinical diagnoses of the patients with caloric inversion, their clinical records were reviewed. Results Out of 9923 patients who underwent bithermal caloric tests, 29 patients (0.29%) showed a caloric inversion. The most common clinical diagnosis was chronic otitis media (21 of 29, 72%). Of the 21 patients with chronic otitis media, 20 patients showed a caloric inversion by warm air irrigation and one patient showed caloric inversion by cold air stimulation. Patients with clinical diagnoses other than chronic otitis media such as sudden sensorineural hearing loss, benign paroxysmal vertigo of childhood and recurrent vestibulopathy showed caloric inversion by warm air irrigation. Caloric inversion by warm water irrigation was observed in patients with lateral semicircular canal cupulopathy and recurrent vestibulopathy. Two patients (one with Meniere's disease and one with age-related dizziness) showed caloric inversion by cold water irrigation. Conclusion Caloric inversion can be observed in various diseases other than chronic otitis media with tympanic membrane perforation. Special care should be taken in the interpretation of caloric test results. Level of Evidence: Level 4.

Vestibular and Oculomotor Findings in Vestibular Migraine Patients.

BACKGROUND: Vestibular migraine (VM) is the most frequent etiology of recurrent spontaneous episodic vertigo. Vestibular and oculomotor abnormalities have been described in VM; however, the diagnosis is currently based on symptoms. The objective of this study was to determine the most frequent abnormalities in videonystagmography (VNG), caloric testing (Cal) and video head impulse test (vHIT) in patients with VM. METHODS: A retrospective cohort study was conducted, including all VM and probable VM patients seen from January 2021 to July 2022. Demographics, auditory symptoms and results via VNG, Cal and vHIT were evaluated. VNG results were compared with a control group. RESULTS: Sixty patients, 81.7% with VM and 18.3% with probable vestibular migraine, were included. VNG revealed the following abnormalities: 21.7% spontaneous nystagmus; 33.3% positional nystagmus, mostly central; 26.7% optokinetic nystagmus; 56.7% smooth pursuit abnormalities and 70% saccade test abnormalities, mostly velocity and latency. An abnormal unilateral caloric response was seen in 22.9%, while vHIT revealed a low gain in at least one canal in 21.7%, and saccades were seen in at least one canal with normal gains in 18.3%. Concordant results between Cal and lateral vHIT were seen in 77.1% of cases. CONCLUSIONS: Although VM is a clinical diagnosis, vestibular and oculomotor abnormalities are commonly seen. The most frequent oculomotor findings were an abnormal saccade test, abnormal smooth pursuit and central positional nystagmus.