I would again point out, if there is no abnormality found on positional and ABB caloric testing
, the evaluation is incomplete without the SBB
A thorough neuro-otologic examination must be performed; this examination should include an audiogram for pure tones and speech, auditory evoked response potentials, and vestibular tests, usually including alternate bilateral bithermal caloric testing
It provides objective diagnostic information and serves as an adjunct to electronystagmographic positional and caloric testing
Electronystagmography and caloric testing
found no unilateral weakness or directional preponderance.
As is the procedure for assessing other patients with dizziness and vertigo, the evaluation of these 160 patients included (1) a careful history, (2) an otolaryngologic examination, (3) a blood workup, (4) an audiometric profile, (5) electronystagmography (ENG) with caloric testing
, (6) radiologic studies, and (7) a dehydration test if necessary.
He explains the anatomy and physiology of normal and impaired vestibular and oculomotor systems, the process of central nervous system compensation, then pretest procedures and the ENG/VNG subtests and their interpretation, including oculomotor, positional/positioning, and caloric testing
stimulates mainly the lateral semi-circular canal.
All patients underwent otologic historytaking, physical examination, audiography, caloric testing
(baseline warm only), and magnetic resonance imaging (to exclude a retrocochlear lesion) before the initial injection.
Follow-up ENG showed nystagmus in the right lateral position, and caloric testing
elicited no warm or cool responses in the right ear.
Electronystagmography (ENG) revealed a direction-changing positional nystagmus, a 35% reduced vestibular response (RVR) left on alternate binaural bithermal caloric testing
, and a type 2 response that revealed the RVR left on simultaneous binaural bithermal testing (figure 1).
This is a very important concept to remember, as caloric testing
during ENG typically measures a low-frequency vestibular response and cannot measure the high-frequency vestibular responses that are more common in everyday life.
However, its sensitivity and specificity are limited because ENG caloric testing
provides (1) information primarily about the lateral semicircular canals, (2) less information regarding possible central pathology, and (3) limited insight into overall balance function.