Vestibular Assessment After Traumatic Brain Injury: Strategies for Identifying Peripheral and Central Loss

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Clinical Presentation of TBI Patients with Vestibular Complaints

Dizziness is among the most significant and persistent complaints following traumatic brain injury (TBI). Research indicates that approximately 83% of patients report dizziness acutely following a TBI, and even after five years, around 37% continue to experience non-rotational dizziness, lightheadedness, and imbalance. More than any other symptom, dizziness and vertigo have independently been linked to poor recovery and disability outcomes in TBI patients — making vestibular identification and intervention critical for this population. Patients presenting at a vestibular clinic are often well beyond the acute phase, typically arriving 18 months or more post-injury, with a complex constellation of symptoms that may include vague non-rotational dizziness, post-traumatic headache, anxiety, brain fog, poor spatial awareness, auditory hypersensitivity, tinnitus, hyperacusis, agoraphobia, and significant cognitive difficulties with memory and planning. Many have developed maladaptive compensatory behaviors such as truncal rigidity, restricting head movement rather than allowing the vestibular system to recalibrate. Visual vertigo — defined as dizziness provoked by complex or moving visual environments — is particularly prevalent: in a consecutive series of 20 TBI patients, 19 presented with clinically significant visual vertigo.

Building a Comprehensive Vestibular Test Battery

Because TBI patients present with overlapping peripheral and central vestibular pathology, no single test is sufficient to characterize the degree or nature of vestibular dysfunction. A thorough assessment typically requires three to three-and-a-half hours, with the case history alone taking up to one-and-a-half hours. The recommended test battery begins with pure-tone audiometry, speech audiometry, speech-in-noise testing where auditory processing difficulties are suspected, tympanometry, and acoustic reflexes. Tympanometry is particularly important as a prerequisite for vestibular evoked myogenic potential (VEMP) testing, since adequate sound conduction through the middle ear is required to elicit a reliable saccular or utricular response at the high stimulus levels used (typically 95 dB HL). Positional testing for benign paroxysmal positional vertigo (BPPV) should be completed early in the session and any identified BPPV treated immediately, as residual canalith debris can confound subsequent testing.

The peripheral vestibular battery should include the video head impulse test (vHIT), the suppression head impulse paradigm (SHIMP), the vestibulo-ocular reflex suppression test (VORs), cervical VEMP (cVEMP), and ocular VEMP (oVEMP). For cVEMPs and oVEMPs, a 95 dB comparison is performed bilaterally, and abolition of the response at 75 dB is observed; failure to abolish at that level raises suspicion for a third-window syndrome such as superior semicircular canal dehiscence or perilymph fistula. The neurovestibular battery — which examines central function — should incorporate smooth pursuit, saccades, subjective visual vertical (SVV), gaze testing, spontaneous nystagmus, vestibular head-shake testing, head heave, ocular counter roll, and the Hennebert (fistula) sign when indicated. Caloric testing, while diagnostically valuable and frequently required for medico-legal purposes, should be approached thoughtfully: patients with significant central pathology may produce hyperresponsive caloric results, and those with high anxiety may not tolerate full bilateral irrigation. Patient comfort and clinical utility should guide the decision.

What the Test Results Typically Reveal

A review of 20 consecutive TBI patients attending a specialist vestibular clinic illustrates why a multi-test approach is essential. BPPV was confirmed in 3 of 20 patients. A positive vHIT — often the only vestibular test performed in many clinic settings — was found in only 4 of 20 patients. By contrast, abnormal VEMP findings were present in 16 of 20 patients, positive VNG findings in 17 of 20, positive central signs in 14 of 20, and positive caloric results in 8 of 14 patients who underwent the test (6 were considered contraindicated). These figures underscore a critical clinical point: relying on vHIT alone would have identified vestibular pathology in only 4 of these patients, and many clinicians — including those running services that claim vestibular status — discharge patients with normal vHIT results without further investigation. The most commonly abnormal findings in this series were smooth pursuits, saccades, SHIMP, and any test measuring otolith organ function. Across the cohort, 16 of 20 patients were ultimately categorized as having combined central and peripheral vestibulopathy, a pattern consistent with the broader literature indicating that in chronic TBI, abnormality rates on caloric testing and horizontal vHIT are generally below 25%.

The Importance of Otolith Assessment

Otolith dysfunction is an underrecognized but highly prevalent sequela of TBI, with studies citing rates of approximately 30% following head trauma and up to 52% following blast injury. When otolith damage is isolated — meaning semicircular canal function is intact — patients may present with non-typical vestibular symptoms: a general sense of unwellness, poor spatial awareness, tilting sensations, waxing and waning imbalance, and a sensation of ongoing motion after a vehicle has stopped. These histories are often vague, and such patients are easily missed in clinics that focus exclusively on canal function. Otolith function is best evaluated using cVEMP (assessing saccular function) and oVEMP (assessing utricular function). While the literature on oVEMP use in TBI is still limited, routine inclusion of both VEMP types is strongly encouraged. Clinicians who perform cVEMP but not oVEMP frequently cite the technical difficulty of the oVEMP, yet with appropriate training and mentorship, the oVEMP proves highly accessible and provides unique information about utricular integrity that no other test can replicate. For TBI patients — particularly those with a history of blast injury — assessment of otolith function should be considered a core component of the vestibular evaluation rather than an optional addition.

Discussion and Clinical Conclusion

There is currently no single diagnostic pattern that characterizes vestibular loss in TBI, and this variability is itself clinically significant. Because damage may affect the peripheral vestibular end organs, the brainstem, the cerebellum, or any combination thereof, the assessment must cast a wide net. A broad test battery is not merely comprehensive — it is essential for responsible clinical management. Vestibular dysfunction in TBI is not simply a peripheral labyrinthine problem; it is a complex, multi-system injury that requires audiologists and vestibular specialists to work within a multidisciplinary team inclusive of neurology, neuropsychology, physiotherapy, and occupational health. When vestibular assessment findings are paired with appropriate rehabilitation — beginning with BPPV treatment, pain management, and cognitive support before progressing to gaze stabilization, otoptic kinetic (OPK) training, and visual vertigo desensitization — outcomes can be highly meaningful, even for patients who have been symptomatic for years.

To learn more and earn CEUs, register for the course, Identifying Vestibular Loss in Head and Brain Trauma.