From exhaustion to depression, even dementia symptoms, how corona can attack the brain
AS IF Covid-19’s vicious toll of deaths and damaged lungs was not harmful enough, arn of a second wave of serious neurological woes involving lasting damage to the brain and nerves.
They are causing mental problems including psychosis, confusion, mania, depression and fatigue, as well as rare but terrifying phenomena such as catatonia (physical and mental shutdown) and Guillain-Barre syndrome, where people’s immune defences destroy their own nerves.
Perhaps most worryingly of all, experts predict that neurological damage from Covid-19 may ultimately cause lasting epidemics of chronic fatigue and depression, even among younger people who had the virus comparatively mildly.
In Britain an alliance has now been created to monitor such cases: CoroNerve — a surveillance programme for neurological Ccomplications of Covid-19. It involves both leading neurologists and psychiatrists.
CoroNerve has gathered case studies of more than 150 adults with symptoms that reflect these emerging problems. Almost a third have suffered from mood disorders and confusion. Significant numbers show evidence of damaging brain inflammation.
In a yet-to-be-published study, posted online last month in the electronic journal SSRN, CoroNerve members reported that, for example, ten patients developed psychosis, six had dementialike symptoms and four had mood disorders such as depression.
Such altered states were ‘disproportionately represented in younger patients’ (aged 20 to 50), it warned.
Dr Benedict Michael, a consultant neurologist, who is leading the CoroNerve initiative, told Good Health: ‘We are receiving clinical reports of unexplained neurological symptoms in patients with Covid-19.
‘These range from forms of encephalitis [brain inflammation] through to psychosis and catatonia. It is quite a broad spectrum.’
MUCH of the damage seems to be wrought by patients’ immune systems overreacting to the virus and sparking harmful inflammatory reactions in brains and nerves, Dr Michael explains.
These may be seen as a neurological parallel to the lung damage wrought by immune cells in people with severe Covid-19, where a ‘cytokine storm’ sparks inflammation that destroys tissues.
But in rarer cases, the neurological problems seem to be caused by the coronavirus infecting the nervous system itself. The virus has been detected in the fluid in victims’ spines and brains.
Serious problems have been studied in Northern Italy, which felt the brunt of the coronavirus pandemic weeks before Ireland.
In mid-March, Alessandro Pezzini, an associate professor of neurology at the University of Brescia, opened a special neurology unit for Covid-19 patients who were also experiencing delirium, seizures and encephalitis.
Globally, the most common neurological symptom reported by Covid-19 patients has been a loss or distortion in smell and taste. Initially, doctors blamed this on the virus damaging smell receptors in the nose.
However, a report at the end of last month in the journal JAMA Neurology described a Covid-19 patient with anosmia (loss of sense of smell) whose MRI scans indicated that coronavirus had infected brain regions associated with smell — the right gyrus rectus and the olfactory bulbs.
After the patient’s sense of smell returned, scans showed her brain was back to normal. The researchers, at Humanitas University in Milan, warned that the virus might infect the brain by entering nerves in the nose.
Commenting on this research in the same journal, Serena Spudich, a professor of neurology and infection specialist at Yale University, in the US, wrote: ‘If the virus has infected brain tissue, the question is, could this spread to other parts of the brain and cause other, more serious neurological effects?’
She added: ‘We know that [the previous epidemic viruses] SARS1 and MERS have been shown to enter the central nervous system.
‘Several coronaviruses have been shown to cause direct brain effects. There is also some evidence that SARS-CoV-2 can do this too.’
So concerned are some neurologists that last week, in the Journal of Alzheimer’s Disease, they called for all Covid-19 patients in hospitals to be given MRI brain scans before they are discharged.
Dr Majid Fotuhi, a neurologist at Johns Hopkins Medicine in Baltimore, US, warned: ‘We need to monitor these patients over time as some of them may develop cognitive decline, brain fog or Alzheimer’s disease in the future.’
Neurological problems do not affect only adults. This month, paediatricians at Columbia University in the US warned in the journal JAMA Pediatrics that among 50 children and adolescents in hospital in New York with Covid-19, 6 per cent had experienced ‘seizures or seizure-like activity’.
An online report, also published this month in the Journal of Neurology, Neurosurgery & Psychiatry, led by CoroNerve, even warned of international cases where Covid-19 patients had developed Guillain-Barre syndrome, in which the body’s immune system mistakenly attacks part of its own peripheral nervous system.
The effects of this rare syndrome (which can be triggered by other viruses) range from brief weakness to devastating paralysis, leaving those affected incapable of breathing independently.
And last week, three Harvard Medical School clinicians posted online the first published case study of a middle-aged Covid-19 patient developing catatonia, a brain condition that left him paralysed in a foetal position, unable to move or speak.
Fortunately, the catatonia was quelled by high doses of lorazepam, a benzodiazepine drug, said the report, which is scheduled to appear in the journal Psychosomatics.
Other viral illnesses, including influenza, have been believed to spark catatonia.
‘We have already seen several cases of catatonia in the UK,’ says Dr Tim Nicholson, who is leading the psychiatric side of the CoroNerve initiatve.
He told Good Health: ‘We are on the alert because of the history of encephalitis lethargica that followed the Spanish flu epidemic of 1919.’
A million people worldwide had encephalitis lethargica in the wake of that pandemic — it causes a high fever, headache, double vision and lethargy. In acute cases, patients went into comas and catatonic states.
‘We are also seeing cognitive problems, psychosis and a mixed bag of other stuff such as manic episodes and depressive episodes,’ says Dr Nicholson, a neuropsychiatrist and a clinical lecturer at the Institute of Psychiatry at King’s College London.
Dr Nicholson wonders if Covid19 might cause a unique syndrome in a very few patients, where neurological effects emerge after the infection is apparently cured.
‘Some patients who have had mild infections with fluey symptoms have subsequently suffered from debilitating fatigue and chronic symptoms such as “brain fog” that last more than a month after the illness,’ he explains.
‘In online communities, such patients are calling themselves “long-haulers”.’
Most of these people are younger adults — in their 20s and 30s — and were previously fit and healthy, says Dr Nicholson.
‘The first cases are emerging clinically. We need six months to diagnose such a syndrome definitively. But three months into the pandemic we have enough evidence to have a pretty clear idea what’s happening.’
Dr Manoj Sivan, an associate clinical professor in physical and rehabilitation medicine, is also concerned for the future. He told Good Health: ‘In our research on the SARS and MERS epidemics, we found patients complaining mainly of breathlessness and fatigue in the first six months postdischarge, and then psychological problems such as anxiety and depression. ‘The neurological problem of chronic fatigue was not much explored in SARS and MERS studies, but we believe it is likely in Covid-19.’
His work currently involves monitoring a sample of Covid-19 patients after they leave hospital.
‘Some have neurological problems such as neuropathy [nerve damage] and myopathy [muscle weakness]. We are seeing neurological complications from the infection in a small proportion of these patients — such as mood problems and encephalopathy,’ he says.
‘Patients are also experiencing depression, anxiety and post-traumatic stress disorder.
‘If problems such as these are addressed early, with timely rehabilitation, we can have good outcomes. The later you leave them, the worse they can end up.
‘This is why it makes economic sense to have resources across the country for the early screening of patients after discharge, to identify their emerging problems and manage them properly.’