Vestibular dysfunction in acute traumatic brain injury

Hani J Marcus,Barry M Seemungal,Natalie Marroney,Brynmor Jones,Heidi Paine,Susie Wolstenholme,Heiko M Rust,Qadeer Arshad,Mark H Wilson,Matthew Sargeant,Rebecca Smith,Kevin Tsang,Katie Collins

doi:10.1007/s00415-019-09403-z

Hani J Marcus, Barry M Seemungal + Show 11 more

Open Access

https://doi.org/10.1007/s00415-019-09403-z

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Abstract

Traumatic brain injury (TBI) is the commonest cause of disability in under-40-year-olds. Vestibular features of dizziness (illusory self-motion) or imbalance which affects 50% of TBI patients at 5 years, increases unemployment threefold in TBI survivors. Unfortunately, vestibular diagnoses are cryptogenic in 25% of chronic TBI cases, impeding therapy. We hypothesized that chronic adaptive brain mechanisms uncouple vestibular symptoms from signs. This predicts a masking of vestibular diagnoses chronically but not acutely. Hence, defining the spectrum of vestibular diagnoses in acute TBI should clarify vestibular diagnoses in chronic TBI. There are, however, no relevant acute TBI data. Of 111 Major Trauma Ward adult admissions screened (median 38-years-old), 96 patients (87%) had subjective dizziness (illusory self-motion) and/or objective imbalance were referred to the senior author (BMS). Symptoms included: feeling unbalanced (58%), headache (50%) and dizziness (40%). In the 47 cases assessed by BMS, gait ataxia was the commonest sign (62%) with half of these cases denying imbalance when asked. Diagnoses included BPPV (38%), acute peripheral unilateral vestibular loss (19%), and migraine phenotype headache (34%), another potential source of vestibular symptoms. In acute TBI, vestibular signs are common, with gait ataxia being the most frequent one. However, patients underreport symptoms. The uncoupling of symptoms from signs likely arises from TBI affecting perceptual mechanisms. Hence, the cryptogenic nature of vestibular symptoms in TBI (acute or chronic) relates to a complex interaction between injury (to peripheral and central vestibular structures and perceptual mechanisms) and brain-adaptation, emphasizing the need for acute prospective, mechanistic studies.

Highlights

Traumatic brain injury (TBI) is the commonest cause of disability in the under 40-year-olds and persisting imbalance and dizziness is an independent predictor of unemployment at 6 months [1]
Patients with acute TBI admitted to our local Major Trauma Ward (MTW) were screened by therapists (SW, KC, and NM) and patients with vestibular symptoms and/or signs were referred to BMS
Vestibular dysfunction is common in acute TBI patients typically combining peripheral and central vestibular diagnoses (Table 2)—as we found in chronic TBI patients with persisting vestibular symptoms [4]

Summary

Introduction

Traumatic brain injury (TBI) is the commonest cause of disability in the under 40-year-olds and persisting imbalance and dizziness is an independent predictor of unemployment at 6 months [1]. Brain adaption, both beneficial and disadvantageous to recovery, may mask the features of vestibular dysfunction in chronic patients. Studying vestibular dysfunction in acute TBI—where chronic adaptive mechanisms have not developed—may clarify the mechanisms of chronic post-TBI dizziness. We hypothesize that acute TBI impairs balance by simultaneously affecting peripheral (inner ear) and central (brain) components of the balance system. This is supported by similar findings in chronic TBI patients [4]. The finding that post-TBI dizziness relates to specific vestibular diagnoses would support the rationale for controlled studies assessing whether active assessment and treatment of vestibular diagnoses in acute TBI accelerate recovery

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Compliance with ethical standards