Imaging in otoneurology

By Marcello Cherchi, MD PhD

For clinicians

In otoneurology most paraclinical evaluation consists of otovestibular testing, but as with many fields in medicine, it is sometimes helpful to obtain imaging. Given the neuroanatomy of the vestibular system, imaging of the head is probably the most common.

Head CT and brain MRI provide different, and often complimentary (Malak et al. 2021) information, and thus both can play a role in the evaluation of patients with otoneurological symptoms (Musat et al. 2025).

Imaging of patients with auditory and vestibular symptoms is common (Connor and Sriskandan 2014), both in outpatient settings, and in emergency department settings (Adams et al. 2022).

Evaluating a patient with acute-onset disequilibrium in the emergency department setting has been a topic of considerable interest, and the literature debates when imaging should be considered, and which imaging modality is appropriate.  Studies have often demonstrated the low diagnostic yield of regular head CT scans (Ahsan et al. 2013).  Studies that have scrutinized the use of both head CTs and brain MRIs in the emergency setting usually report low diagnostic yield of both modalities (Shah et al. 2023).  Some studies have shown that the utilization of head CT and brain MRI in the emergency setting varies considerably, without any clear corresponding diagnostic advantage (Kim et al. 2012).

In the outpatient setting, brain MRI generally has shown greater diagnostic utility in auditory and vestibular disease (Bulakbasi and Pabuscu 2007), though disadvantages (compared to CT) include that it is less widely available, it is slower, and it is more expensive.

MRI of the brain and internal auditory canals without and with contrast is perhaps the most common type of imaging checked in otoneurology patients. This is a reasonable imaging study for a patient suspected of having a brainstem lesion, a vestibular schwannoma, an intralabyrinthine schwannoma, demyelinating disease, etc.

Temporal bone CT without contrast is perhaps the next most common type of imaging. This is reasonable to check in a patient whose history and otovestibular test results are suggestive of semicircular canal dehiscence.

There are some diagnoses for which both MRI and CT may be helpful. Examples include otologic malformations (large vestibular aqueduct, large cochlear aqueduct, Mondini dysplasia, Pendred syndrome).

Angiography is occasionally indicated. For example, for patients with pulsatile tinnitus in whom a discrete anatomical vascular cause is suspected it may be reasonable to consider MR angiography (often time-resolved MRA). If that is unrevealing, it may be reasonable to consider to CT angiography.

Doppler ultrasound studies (such as carotid and vertebral ultrasound, transcranial Doppler) are rarely helpful in otoneurology.

Cervical spine imaging is occasionally helpful. For example, in patients being evaluated for possible Chiari malformation, a cervical spine MRI may help characterize this lesion better, and identify whether a syrinx is present. In patients with possible cervicogenic vertigo, a cervical spine MRI may be helpful to exclude competing diagnoses.

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