Mild traumatic brain injury and dementia — court confirms still no causal link

The executors of the estate of the late Geoffrey Charles Ivory v Swale Borough Council

On 4 April 2023 HHJ Timothy Parker handed down judgment in this important case with regard to the judge’s findings on the causal link, or lack thereof, between a mild traumatic brain injury (TBI) and the development of dementia, upholding the findings of the court in Mathieu v Hinds & Aviva [2022]EWCH (QB) on the current state of science on the subject. The judge also confirmed the correct approach to considering the question of causation when a claimant suffers from dementia, finding that the claimant’s experts were approaching it asking the wrong question.

The parties had jointly instructed a neuroradiologist and cardiologist but the parties obtained their own evidence in the fields of neurology and psychiatry. The experts for the claimants were Dr Steven Allder (neurologist) and Professor Elliott (psychiatrist). The experts for the defendant were Dr Pamela Crawford (neurologist) and Dr Hugh Series (psychiatrist).

On 14 May 2014, the late Mr Ivory had fallen in a car park when age 82, sustaining injury to his head and face. The contemporaneous medical records recorded no loss of consciousness but there were reports that he had been ‘a little dazed’ at first. Mr Ivory attended hospital and was discharged home the same night. Two months later, in July 2014, Mr Ivory suffered symptoms of a seizure and attended hospital where he was diagnosed with an ‘acute on chronic subdural hematoma’ (SDH).

Mr Ivory had two more similar episodes, the last being in September 2014. Mr Ivory had a number of co-morbidities including cardiac problems, COPD and Type II diabetes (the latter increases the risk of dementia). Proceedings were served on 5 October 2017. By the date of the defendant’s experts’ examinations of Mr Ivory in 2018, he was suffering from dementia and unable to provide details of the accident or his symptoms since.

Evidence was given by family members. Mr Ivory died of unrelated causes on 25 January 2020 aged 87 and his executors took over proceedings. The family reported a step change decline in cognitive functioning after the seizure in July 2014 and brought the claim pleading that Mr Ivory’s dementia had been caused by the accident. The special damages included substantial care home fees, Mr Ivory having been unable to remain at home once his dementia progressed.

Dr Allder for the claimants was of the opinion that:

• The accident of May 2014 caused a TBI and because of the subsequent SDH noted in July 2014 it should be classified as moderate-severe.
• Mr Ivory had reported typical post-concussional symptoms.
• In reliance on the family’s account that there was a step-change decline after July 2014, the extent of the decline over a short period of time (from July 2014 to 2018) made it, on the balance of probabilities, unlikely that the cause of the decline was vascular dementia.
• The SDH noted in July 2014 was compressing the brain. In his view this compression was compelling evidence of damage to the brain, both to its surface and to its deeper structures, with resulting cognitive impairment. Scientific literature shows that there are or may be long term adverse effects from subdural haematomas.

Dr Allder contended that there were three possible mechanisms for the accident having caused the dementia:

• the presence of blood from the SDH on the outer surface of the brain might trigger a neurotoxic cascade
• the injury could trigger a chronic inflammatory response

• the injury might somehow trigger the interaction between the proteins amyloid and tau which leads to clogging of neurons, being the condition which underlies Alzheimer’s disease

The defendant contended that:

• There was no TBI
• There were pre-accident medical entries reflecting cognitive decline
• The progression of the dementia followed its expected course, there was no step-change in cognitive decline in July 2014
• Mr Ivory did not have post-traumatic epilepsy
• The SDH did not cause lasting damage
• There is no evidence that a mild TBI or SDH causes dementia through a neurotoxic cascade or inflammatory response

On cross-examination, Dr Crawford agreed that, on some definitions of traumatic brain injury in clinical use, Mr Ivory could have been diagnosed with mild TBI because of the reference to his having been ‘dazed’ but contended that the classic symptoms of a TBI were lacking. She did not agree that the post-accident symptoms relied on by Dr Allder showed post-concussional syndrome. 

HHJ Parker found on TBI that there was no loss of consciousness. After the accident, Mr Ivory was shaken and took to his bed, but there was no indication in the evidence that he was confused or otherwise suffered a sudden cognitive deterioration. Given the description by two sources that Mr Ivory was dazed, he would be regarded for the purposes of the CDC criteria as having had transient confusion, disorientation or impaired consciousness, and thus that he did satisfy that test for mTBI but (at most) at the least serious end of the spectrum. He found that there was no step-change in cognitive decline in July 2014. Accepting Dr Crawford’s specialized interest in epilepsy, he found there was no post-traumatic epilepsy.

On causation of the dementia, as in Mathieu, the court had to consider in detail the state of the current science.

Dr Allder accepted in cross-examination that all of the scientific papers discussed dealt with the association between TBI and dementia, and not causation. He acknowledged that “the mechanisms by which TBI generates dementia are still being worked out”.

The judge rejected Dr Allder’s arguments.

As to the way to approach causation, HHJ Parker summarised that the issue for the court is whether the accident of 14 May 2014 caused or contributed to Mr Ivory’s dementia. The fact that Mr Ivory did develop dementia is an undisputed starting point. In assessing what caused the dementia, it is necessary to consider how likely it is that the pre-accident history of memory problems was a symptom of an underlying progressive condition which eventually developed into dementia.

The appropriate question is not ‘of those who have mild cognitive symptoms, how many develop dementia?’ but, as Dr Series said, ‘of those who have dementia, what proportion start with mild cognitive symptoms?’ If, as is undisputed, the answer is that a high proportion do, then it is likely that in many cases the MCI was a first sign of a developing problem.

That is the context in which the claimants have to show that the dementia in this case was brought about by the accident and not by a progressive condition which was already under way. The fact that most people with MCI do not develop dementia is irrelevant to the enquiry. The proportion of people who buy a lottery ticket and win the prize is tiny, but that does not make it unlikely that a win was caused by buying a ticket.

The claimants were awarded less than 10% of their pleaded claim, failing to beat the defendant’s Part 36 offer made in 2018.

Scientific research continues and we can expect more litigation over the link between TBI and dementia over the coming years, remembering that each case will always have to be looked at on its own facts.

Counsel for the defendant: Niall McLean of 12 Kings Bench Walk