Four new long-COVID studies reveal that 10% of French patients infected early in the pandemic still had symptoms 1 year later, SARS-CoV-2 can profoundly damage the brain for months, and very stressful events exacerbate persistent symptoms.
For some, a long road to recovery
French researchers published a new study in JAMA Network Open on 1-year rates of long COVID among 53,047 adults in three population-based groups who took a nationwide survey from Apr 1 to Jun 30, 2020. The researchers obtained blood samples for serologic confirmation of infection from May 1 to Nov 30, 2020, and fielded an online follow-up questionnaire from Jun 1 to Sep 30, 2021. Average participant age was 50.9 years, and 63.7% were women.
In total, 3,972 people had tested positive for SARS-CoV-2, with 2,647 (66.6%) of them reporting at least one symptom during their infections. Of the 2,647 participants, 32.5% said they had at least one COVID-19 symptom for 2 months or longer.
The estimated proportion of participants who had at least one lingering symptom was 18.4% at 6 months, 10.1% at 12 months, and 7.8% after 18 months. Among participants who had symptomatic infections, an estimated 33.6% had more than five symptoms 1 week after infection, falling to 2.8% at 2 months.
An estimated 97.5% of participants with weakness, 94.2% of those with impaired attention or concentration, and 77.5% of those with memory loss reported symptom resolution at 1 year.
The most common long-COVID symptoms were shortness of breath (26.5%), joint pain (26.9%), loss of smell or taste (27.0%), weakness (20.6%), impaired attention or concentration (22.3%), memory loss (40.0%), and sleep disorders (36.6%).
Risk factors for lingering symptoms were age older than 60 years (hazard ratio [HR], 0.78), female sex (HR, 0.64), a history of cancer (HR, 0.61) or tobacco use (HR, 0.80), obesity (HR, 0.75), and more than four symptoms during infection (HR, 0.43).
In general, women were slower to recover their sense of taste or smell. Older people, women, and those with a history of anxiety or depression, cancer, diabetes, tobacco use, obesity, or a higher number of acute symptoms were slower to recover from weakness. Slow resolution of impaired attention or concentration was tied only to older age.
"Given the high level of cumulative incidence of COVID-19, the absolute prevalent number of people with persistent symptoms is a public health concern," the authors wrote. "These findings suggest the need to optimally manage comorbid conditions in individuals with long COVID to help reduce the duration of their symptoms."
Cognitive deficits after even mild COVID
Two studies presented this week at the Society for Neuroscience annual meeting in San Diego describe profound brain damage that lingers for months after COVID-19 infection.
In one study, Mexican researchers used functional magnetic resonance imaging (fMRI) to assess the sensorimotor brain regions of 240 children 10 to 13 years old infected with SARS-CoV-2 in the previous 4 to 15 months. Relative to controls, COVID-19 patients still required more resources in three areas of the brain.
In the other study, Brazilian scientists using MRI and positron emission tomography (PET) imaging found that about a quarter of adults who had mild COVID-19 had impaired ability to coordinate their fine-motor skills and spatial abilities 4 months after infection. The findings were associated with molecular and clinical changes in the brain.
"This is preliminary evidence that cognitive deficit from neuroinflammation may result from even mild COVID-19 symptoms," the researchers said in a Society for Neuroscience news release.
The researchers said that while SARS-CoV-2 doesn't directly enter the brain, it can still cause long-term brain-function changes through inflammation.
Robyn Klein, MD, PhD, of Washington University and a panel moderator, said it isn't the first time that a flulike viral disease has been tied to an increased risk of dementia. "But one of the most important aspects of this work is the magnitude of people potentially affected by this—millions upon millions," she said.
"We need to move on to alternative hypotheses for these neurologic diseases; we also need to inform the public and physicians that this is a real illness and that they should be proactive in addressing it," she added.
Major life stressors tied to higher risk
In a study published last week in the Journal of Neurological Sciences, the NYU Neurology COVID-19 Study Team assessed hospitalized COVID-19 patients 6 and 12 months after diagnosis using the modified Rankin Scale (mRS), the Barthel Index, the telephone Montreal Cognitive Assessment (t-MoCA), and Neuro-QoL (quality-of-life) tests for anxiety, depression, fatigue, sleep, and long-COVID symptoms from Mar 10 to May 20, 2020.
Of 790 COVID-19 survivors, 57% completed a 6- or 12-month assessment, and 77 of 451 (17%) died between hospital release and 12-month follow-up.
At 12 months, 121 (51%) of 239 participants reported significant life stressors. Financial or food insecurity, death of a close contact, and new disability were the strongest predictors of worse mRS, Barthel Index, depression, fatigue, and sleep scores and persistent symptoms (adjusted odds ratios, 2.5 to 20.8).
Other predictors of poor outcome were older age (tied to worse mRS, Barthel, t-MoCA, and depression scores), baseline disability (linked to worse mRS, fatigue, and Barthel scores), female sex (associated with worse Barthel and anxiety scores), and severe COVID-19 (linked to worse Barthel index scores and lingering symptoms).
The researchers said that pandemic-related stress may have unmasked previously undiagnosed mood disorders.
"Therapies that lessen the trauma of the most stress-inducing life events need to be a central part of treatment for long COVID, with more research needed to validate the best approaches," lead author Jennifer Frontera, MD, said in an NYU Langone Health news release.