Eye motility and auditory brainstem response dysfunction after whiplash injury.

The aim of this study was to identify the prevalence of brain/brainstem dysfunction after acute whiplash trauma (grades II and III according to the Quebec Task Force Classification on whiplash-associated disorders) and to investigate a possible correlation between the development of chronic symptoms and objective findings from auditory brainstem response (ABR) and eye motility tests. We used ABR and oculomotor tests and a thorough clinical, subjective and psychological evaluation in a sample of prospective whiplash trauma patients who were followed up for 2 years after the trauma. The initial test results did not reveal any prognostic clinical signs for the tested group as a whole, but we could discriminate some patients with clinical symptoms and signs paired with pathologic test results. Over time, some patients normalized clinically and their test results improved while others deteriorated clinically and their test results were worse at the 2-year investigation. Our findings of moderate derangements in the tests could be the effects of pain and/or changed cervical afferent activity at the brain/brainstem level, while eye motility dysfunction, in addition to pathological neuro-otological findings in a small proportion of the patients with severe symptoms, could be explained by lesions to the brain/brainstem.