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Early in the pandemic we learned that Covid could lead to stroke, brain hemorrhage, psychosis, meningitis and a raft of central nervous system problems.
The
findings were largely based on patients who died, so it was hard to
know whether these conditions were triggered by hyper-inflammation and
blood clots resulting from a severe illness or if the coronavirus was
affecting the brain more specifically. When
patients, even after a mild case, complained months later of lingering
problems concentrating, multitasking, remembering words and sleeping,
some scientists worried these long-haul symptoms could be a sign of a
broader set of neuropsychiatric effects. Such
concerns were heightened in March, when University of Oxford
researchers published findings from a study in which they compared brain
MRI scans taken before and after 2020. They found people who had mostly
a mild case of Covid displayed a 0.2%-to-2% greater reduction in brain size
compared with their uninfected counterparts. Covid survivors also
showed greater cognitive decline based on their performance undertaking
complex tasks. It’s
too early to tell yet whether the changes are benign and can be
countered by the brain’s ability to rewire, or if they’re
progressive and predispose for incurable neurodegenerative diseases,
like Alzheimer’s and Parkinson’s disease. Evidence for the latter is
building though. This week, Oxford researchers
showed that the likelihood of being diagnosed with psychotic disorders,
dementia, cognitive deficits or so-called brain fog, epilepsy and
seizures remained higher two years after Covid than after other
respiratory infections. “The
picture is certainly not pretty,” says Ziyad Al-Aly, chief of research
and development at the VA St. Louis Health Care System and a clinical
epidemiologist at Washington University, whose own studies have led to
important early findings about long Covid. The fact that the increased risk persisted at two years “is rather worrisome,” he said. A doctor who read my report
emailed to tell me about his son, also a doctor, who displayed
neurological changes after a severe case in 2020. The younger man was
diagnosed in July with bipolar disorder and psychosis. While the father
acknowledged that the causes of such conditions are multifactorial, the
study confirmed his suspicions about his son. It’s a sad reminder of the impact these conditions have on individuals and their families — and
the importance of population-based registries to gather
real-world information on the diseases accumulating in the pandemic’s
wake. — Jason Gale |