Breakthrough in diagnosing imbalance in TBI patients

A condition that causes loss of vertigo perception and imbalance has been diagnosed in traumatic brain injury patients for the first time, which could yield breakthroughs in the development of new treatments and diagnostic tests.

Of 37 patients with acute traumatic brain injury (TBI) involved in the study, 15 were diagnosed with a newly – characterised neurological diagnosis called vestibular agnosia – a condition in the brain which results in loss of vertigo perception and imbalance.

The impact of such a condition is shown through statistics which reveal TBI patients with balance problems are twice as likely to be unemployed six months after their injury, compared to those without balance dysfunction.

The research, from Imperial College London and clinicians at Imperial College Healthcare NHS Trust, also found that these patients have worse balance problems than TBI patients without vestibular agnosia and are unlikely to experience dizziness – one of the main criteria to assess balance problems in TBI patients.

As a result, doctors are seven times more likely to miss cases of balance dysfunction in TBI patients with vestibular agnosia than in those without.

The study is the first to show vestibular agnosia in TBI patients and the researchers believe that current guidelines should be updated to include screening and laboratory tests for TBI patients for vestibular agnosia so that it can be diagnosed and managed at an earlier stage.

“Imbalance affects a majority of TBI patients leading to them having falls fairly frequently,” says study lead Dr Barry Seemungal, consultant neurologist at Imperial College Healthcare NHS Trust and honorary senior lecturer in the Department of Brain Sciences at Imperial College London.

“It can affect patients’ physical and mental wellbeing, as well as affecting patients financially as it can make it hard for them to return to work post treatment.

“Some of these adults also have to support a family or care for elderly patients, meaning the knock-on effect of ill-health in this group is multi-generational. Frequent falls in this patient group also have a financial impact on the NHS due to frequent readmissions to hospitals.

“Our study is the first to identify loss of vertigo in some TBI patients and explain why they have balance problems and falls. This finding could lead to the development of new treatments and diagnostic tests.

“Importantly, current guidelines require updating so that clinicians can screen for vestibular agnosia in TBI patients at a much earlier stage as common treatable balance problems will be missed if the patients do not have access to these tests.

“We believe that diagnosing and treating these balance problems early will lead to a quicker recovery and a better quality of life for our patients.”

TBI is the commonest cause of chronic disability in under 40s and imbalance is one of the major complaints.

A key step in treating TBI imbalance is to understand the underlying causes, but previous studies could not identify a clear-cut cause in TBI patients with chronic imbalance.

Additionally, doctors looking after TBI patients only look for balance problems if patients complain of dizziness, which some patients who have frequent falls don’t experience.

Vestibular agnosia is a condition linked to both loss of vertigo perception and imbalance, due to damage to a neural circuit in the right temporal lobe of the brain.

Although vestibular agnosia can be observed at the bedside, it is most accurately diagnosed in the laboratory using a test developed by Dr Seemungal.

There are currently no specific treatments for vestibular agnosia but its recognition is important as patients may be at risk of falls and may have treatable inner ear problems, despite not complaining of vertigo.