Delirium is a common symptom of coronavirus in elderly patients, found in around one in three infected over-65s.
Researchers say delirium can be particularly detrimental to elderly people, increasing their likelihood of severe disease and death.
The US-wide study looked at 817 older patients who tested positive for the coronavirus, 226 (28 per cent) of whom were diagnosed with delirium.
The cohort had an average age of 78, and 84 (37 per cent) of the delirious patients did not have any typical Covid symptoms — such as a fever or shortness of breath.
Eighty-four delirious patients died in hospital, and scientists say delirium increases the risk of death by 24 per cent and likelihood of ICU admission by 67 per cent.
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A US-wide study looked at 817 older patients who tested positive for the coronavirus and 226 (28 per cent) were diagnosed with delirium
Doctors at Massachusetts General Hospital worked with scientists at Harvard to scrutinise any relationship between cases, deaths and delirium.
Delirium is a state that comes on suddenly, in which people get confused, struggle to think clearly and may hallucinate, become agitated or have mood swings.
Covid-19 causes delirium, stroke and nerve damage in ‘a higher than expected’ number of patients
Infection with the coronavirus can cause delirium, stroke and nerve damage in ‘a higher than expected number of patients’, a study has found.
Experts from University College London have reported a ‘concerning increase’ amid the pandemic of a rare brain inflammation known to be triggered by viral infections.
Typically seen in children, acute disseminated encephalomyelitis — or ‘ADEM’, for short — affects the both the brain and spinal cord.
The condition — which can follow on from minor infections such as colds — sees immune cells activated to attack the fatty protective coating that covers nerves.
The researchers have warned that clinicians need to be aware of the risk of neurological effects to help early diagnoses and improve patient outcomes.
The condition is caused by problems in the brain and can make people more likely to get seriously ill or die in hospital because their bodies become generally weaker and less able to recover, and the effects on the brain can be long-lasting or permanent.
The study, published today in the journal JAMA Network Open, looked at 817 cases of Covid-19 in over-65s at seven hospitals across the US.
Fever was the most common symptom, in more than half (56 per cent) of cases, closely followed by shortness of breath (51 per cent). 412 out of 817 patients (slightly over 50 per cent) had a cough.
Delirium was the sixth most common symptom, behind fever, coughing, weakness, hypoxia and shortness of breath.
‘Factors associated with risk of delirium included older age, prior psychoactive medication use, assisted living or skilled nursing facility residence, vision or hearing impairment, stroke, and Parkinson disease,’ the researchers write.
‘Delirium at presentation was significantly associated with increased risk for poor hospital outcomes, including ICU stay, discharge to a rehabilitation facility, and death.’
Data reveals people over 75 are at a 51 per cent increased risk of developing delirium following infection with the coronavirus, whereas people with prior vision impairment are 98 per cent more likely than the average pensioner.
‘Our study demonstrates that it is critical to recognise that older adults with COVID-19 may present with delirium as the primary or sole symptom,’ the researchers add.
‘In addition, delirium is an important risk marker to identify patients at high risk for poor outcomes, including death.’