Findings: 1) Acute TBI patients may lose vertigo sensation 'VESTIBULAR AGNOSIA' (VA), quantified via vestibular perceptual thresholds of self-motion
https://pubmed.ncbi.nlm.nih.gov/15735328/ . See clinical video in supp info:
https://academic.oup.com/brain/advance-article/doi/10.1093/brain/awaa386/6050089#supplementary-data 2) Posturography - VA patients worse balance..
...compared to non-VA TBI cases. In unbalanced TBI cases, VA (i.e. vestibular perceptual thresholds) correlate with disrupted white matter microstructure (whole brain diffusion tensor imaging) in the right inferior longitudinal fasciculus in temporal cortex. 4) Clinicians..
...7x less to find BPPV (common inner ear problem in TBI) in VA vs. non-VA patients. So most unbalanced cases were least symptomatic & also least likely to recieve medical attention. Note circa 50% acute TBI cases have BPPV, but in study cohort, ear probs treated or excluded.
More implications. Other brain patients
#dementia #Alzheimers #Parkinsons, see:
https://pubmed.ncbi.nlm.nih.gov/26800658/ and frail elderly also display vestibular agnosia. These patients may have treatable balance disorders but not complain of vertigo.
UK NICE guidelines does not include screening for BPPV. Yet many elderly fallers have BPPV but without vertigo. Time to review the falls guidelines:
https://www.bmj.com/content/353/bmj.i1419/rr-2
BPPV- Benign Paroxysmal Positional Vertigo - is it time to review the nomenclature for BPPV? It is not benign. BPPV causes falls and BPPV is caused by falls. BPPV may occur without vertigo in the most vulnerable patients who are most likely to have vestibular agnosia.
Vestibular agnosia makes retrospective assessment of vestibular dysfunction in TBI unreliable. Symptoms and signs do not correlate acutely. Implications for research data and medico-legal cases. Forthcoming paper will present our longitudinal follow-up of TBI cases.
Finally,
to
#NHS staff, patients & families. Tough study! Team
1,000s hrs work ward, lab, office, home. 1K screened, 150 assessed, 37 recruited. See also 10 pilot VA patients in supp info
https://academic.oup.com/brain/advance-article/doi/10.1093/brain/awaa386/6050089#supplementary-data. More papers to follow.
Read on Twitter
See @Brain1878 our study of vestibular dysfunction in traumatic brain injury https://academic.oup.com/brain/advance-article/doi/10.1093/brain/awaa386/6050089?guestAccessKey=388b9d20-5298-43bc-a7e7-83effc1b6ad8 Newly described vestibular cognitive syndrome, VESTIBULAR AGNOSIA. See thread @The_MRC @ImperialCharity @ImperialBrains @VestibularNeuro @ImperialBRC @CDMRP @ImperialAHSC #TBI
