Dementia cases surge as Covid ‘attacks the brain’
Concerns over patients aged under 65 who develop delirium
THE pandemic is leading to a surge in dementia cases amid growing evidence that Covid-19 “attacks the brain”.
One of the main symptoms of the virus – the loss of sense of taste and smell – is neurological and experts say it is unclear if there is more lasting cognitive impairment.
A number of studies are under way looking at the impact of Covid on the brain, led by Dr Alan Carson, Professor of Neuropsychiatry at Edinburgh University.
He said there was already “good data” showing that dementia cases increase markedly in the six months after Covid infections.
He said this only seemed to be the case when patients had developed delirium – where patients with viral infections become disorientated.
But he said Covid was causing this to happen more frequently and, more unusually, in patients aged under 65.
Alzheimer Scotland has previously warned social isolation and lack of support is accelerating symptoms in those who have already been diagnosed with dementia, including people with milder forms of the illness, putting a strain on lockdown services.
Paola Barbarino, chief executive of Alzheimer’s Disease International, a global umbrella group of 100 Alzheimer’s associations, said “we should be worried” because there is so much scientists don’t yet know about the impact of Covid on the brain.
She said: “We know the external manifestation [of Covid-19] is that lack of breath and respiratory problems, but we are now realising there is a much bigger damage to the brain.”
Dr Carson, who is involved with the Centre For Clinical Brain Sciences at the University of Edinburgh, said he was particularly interested in the impact of “Long Covid”, which he said is unlikely to be one condition but a variety of complications of viral infection.
He said: “It’s helpful for campaigning purposes but I’m not sure it’s so helpful in the diagnosis and treatment of patients.
“My particular interest is on cognitive symptoms, so that would
be problems with memory or concentration, thinking or judgment.
“Quite a few patients have identified these neuro-psychiatric symptoms among the most common and disabling consequences.
“I think they will range from one end – patients with precipitated dementia illnesses – to, at the other end, anxiety.
“With regard to dementia, we know the processes of dementia probably start 10 to 20 years before the illness becomes clinically apparent.
“We know if you develop delirium, where your body gets a sort of inflammatory response leading to the infection, that it can cause an impact on the brain such that you become disorientated and don’t know what date it is, where you are, etcetera.
“We already know this has a bad effect on brains if they are about to suffer from Alzheimer disease or already are. You advance several years in the same number of weeks.
“There is good data showing that in the six months after Covid infection there is an increased rate of dementia but only in those patients who develop delirium.
“That is exactly what we would predict from what we already know about delirium. The thing that is unusual is Covid is causing this to happen more frequently than other respiratory viruses.
“It would be very rare for us to see somebody delirious coming into hospital with influenza under 65, but that happens quite frequently with Covid.”
He said the evidence that Covid is leading to more dementia cases is “clear cut” but added: “I do worry we have jumped forward to thinking that everything with Covid must be novel rather than thinking, ‘what do we already know about some of these conditions?’ – but that’s not to say that those studies shouldn’t be done.”
Ms Barbarino said it is probable there will be an initial statistical decline in dementia rates globally due to significant mortality in the population and the impact of disruption to diagnoses.
Deaths due to Covid-19 among people living with dementia as
a proportion of the population have been estimated to be as high as 26 per cent in the UK.
However she said referrals are likely to rise in the coming months, adding that the impact of Covid on neurological conditions had been “the greatest by far of any other underlying condition”.
“It’s clear that one of the things Covid-19 attacks is the brain,” she said.
“One of the main symptoms is loss of sense of taste and smell, which is a neurological problem. Then you have to consider if this is having an impact that will last a longer time.
“There seems to be three main mechanisms of Covid: there is direct brain invasion of Covid and that seems to lead to sense of smell and taste loss. Then, there seems to be something related to the brain/ blood barrier. So there is something that prevents the blood going into the brain caused by Covid.
“Then there is some kind of inflammation mechanism that we don’t yet understand. There are other things, like there may be micro-vascular damage.
“There are studies suggesting there is a lot going on in the brain that needs further investigation and this is exactly what we are looking at now.
“We already know that anything that diminishes one’s cognitive reserve is going to allow a degenerative disorder to accelerate.
“There is still so much we don’t know about how the brain works, but it seems quite obvious there will be a correlation.” She added: “I think we should be worried and it is really, really important that one tries not to catch Covid – even those in the categories deemed not to be at risk.
“We don’t really know what the long-term effects are on the brain, which is such a complicated organ.”
Evidence that the pandemic is having a disproportionate impact on people with dementia has been backed up by a number of studies, data and charity reports.
Figures suggest the number of women dying with the illness at home has risen by as much as 75% , which has been attributed to over-stretched health and social care services during the pandemic.
From March 14 last year to September 11 there were 3,116 deaths of women in the community attributed to dementia, compared with a five-year average of 1,781.
Health data analysts said the fact the figures have risen so sharply in a short time suggested “pressure on health pathways”.
National Records of Scotland figures show the number of deaths from dementia rose by a quarter (24.5%) between April and June.
A breakdown in community supports and pressure on carers is also said to have led to more elderly Scots, including those with dementia, being admitted to care homes and at an earlier stage than expected.
Alzheimer Scotland said it was hearing daily of the “devastating” impact on the lives of those with dementia and their families because “everything they rely on has been completely disrupted”.
The charity said many had experienced an acceleration in their symptoms, both cognitively and physically, while helpline staff reported that many carers, who may be elderly themselves, were at “breaking point”.
Some carers reduced or cancelled home support due to fear of the virus or used savings to pay privately for care for the person living with dementia.
Jim Pearson, director of policy and research for the charity, said: “In the absence of alternatives, many people with dementia have moved to care homes sooner than may have been necessary, which is often an extremely difficult decision for them and their families.’
The Herald is backing Alzheimer Scotland’s campaign for fairer care home fees for people living with advanced dementia.