from the not-dead-is-not-enough dept.
COVID-19 can cause worrying neurological symptoms like a loss of smell and taste, but Australian scientists are warning the damage the virus causes to the brain may also lead to more serious conditions such as Parkinson's disease.
[...] It has happened before.
Five years after the Spanish flu pandemic in the early 1900s, there was up to a three-fold increase in the incidence of Parkinson's disease.
Kevin Barnham from the Florey Institute of Neuroscience and Mental Health said he believed a similar "silent wave" of neurological illness would follow this pandemic.
"Parkinson's disease is a complex illness, but one of the causes is inflammation, and the virus helps to drive that inflammation," he said.
"Once the inflammation gets into the brain, it starts a cascade of events which can ultimately lead to Parkinson's disease.
Researchers outlined their concerns in a study published today in the Journal of Parkinson's Disease.
The process is known as the "two-hit hypothesis".
The brain gets inflamed from something like a virus, then something else comes along later causing more damage and eventually Parkinson's disease develops.
"Evidence is already suggesting the triggers for Parkinson's disease are there with this virus," Professor Barnham said.
Medical experts said it was too early to know how many people who had COVID-19 would go on to develop the disease.
"I believe the risk is real," Professor Barnham said.
"We can't put a number on it, but with 30 million people worldwide affected by this virus, even a small shift in the risk of getting Parkinson's would lead to many more people being diagnosed.
One in three COVID-19 survivors in a study of more than 230,000 mostly American patients were diagnosed with a brain or psychiatric disorder within six months, suggesting the pandemic could lead to a wave of mental and neurological problems, scientists said.
Researchers who conducted the analysis said it was not clear how the virus was linked to psychiatric conditions such as anxiety and depression, but that these were the most common diagnoses among the 14 disorders they looked at.
[...] The new findings, published in the Lancet Psychiatry journal, analysed health records of 236,379 COVID-19 patients, mostly from the United States, and found 34 per cent had been diagnosed with neurological or psychiatric illnesses within six months.
The Lancet article includes this disclaimer:
Big-data studies of this kind have intrinsic limitations, even when drawing on 81 million people, 236 379 of whom had COVID-19. In this pandemic context, not all individuals who are infected with SARS-CoV-2 (particularly those with mild or asymptomatic illness) will be diagnosed, which could result in some contamination of the comparison groups.
The question: will severe, enduring, and less common conditions such as psychoses behave more like neurological disorders or common mental disorders? Among the COVID-19 cohort in this study, a first diagnosis of a psychotic disorder was substantially more common in patients hospitalised with COVID-19.
Lungs, hearts and brains..
Jonathan P Rogers. A longer look at COVID-19 and neuropsychiatric outcomes, The Lancet Psychiatry (DOI: 10.1016/S2215-0366(21)00120-6)