April 17, 2024 -- Four years ago in the spring of 2020, doctors and patients coined the term “long COVID” to describe a form of the viral infection from which recovery seemed impossible.
What started as a pandemic that killed nearly 3 million people globally in 2020 alone would turn into a chronic disease causing a long list of symptoms — from extreme fatigue, to brain fog, tremors, nausea, headaches, rapid heartbeat, and more. Today of Americans report symptoms of long COVID, and many have never recovered.
But today, 4 years in, we’ve come a long way, even though there’s still a lot that we don’t understand about the condition. Doctors have a much greater understanding that long COVID exists and can cause serious long-term symptoms.
While physicians may not have a blanket diagnostic tool that works for all long COVID patients, they have refined existing tests for more accurate results, said Nisha Viswanathan, MD, director of the UCLA Long COVID program. A range of new treatments, now undergoing clinical trials, have emerged that have proved to be effective in managing long COVID symptoms.
Testing for of a class of compounds known as catecholamines, for example, is now commonly used to diagnose long COVID, particularly in those who have dysautonomia, a condition caused by dysfunction of the autonomic nervous system and marked by dizziness, low blood pressure, nausea, and brain fog. Examples of catecholamines are dopamine and adrenaline.
Very high levels of the neurotransmitter in patients, for example, were shown to indicate long COVID in a January 2021 study published in the journal Clinical Medicine.
Certain biomarkers have also been shown to be linked to the condition, including low serotonin levels. A groundbreaking study published this year in Cell found lower serotonin levels in long COVID patients driven by low levels of circulating SARS-CoV-2, the virus that causes the condition.
Still, Viswanathan said, long COVID is a disease diagnosed by figuring out what a patient does not have — by ruling out other causes — rather than what they do. “It’s still a moving target,” she said, meaning that the disease is always changing based on the variant of acute COVID.
Promising Treatments Have Emerged
Dysautonomia, and especially the associated brain fog, fatigue, and dizziness, are now common conditions. As a result, doctors have gotten better at treating them. The vagus nerve is the main nerve of the parasympathetic nervous system that controls everything from digestion to mental health. A February 2022 pilot study suggested a link between vagus nerve dysfunction and some long COVID symptoms.
One form of treatment involves using a device to stimulate the vagus nerve with electrical impulses. Viswanathan has been using the treatment in patients with fatigue, brain fog, anxiety, and depression — and results, she said, have been positive.
“This is something tangible that we can offer to patients," she said.
A cure for long COVID remain elusive, but doctors have many more tools for symptom management than before, said Ziyad Al-Aly, MD, a global expert on long COVID and chief of research and development at the Veterans Affairs St. Louis Health Care System.
For example, doctors are using beta blockers to treat postural tachycardia syndrome (POTS), a symptom of long COVID that happens when the heart rate increases rapidly after someone stands up or lies down. Beta blockers, normally used to lower blood pressure or control abnormal heart rhythm, like the off-label medication ivabradine, have been used clinically to control heart rate, according to a March 2022 study published in the journal HeartRhythm Case Reports.
“It’s not a cure, but beta blockers can help patients manage their symptoms,” said Al-Aly.
Additionally, some patients respond well to low-doses of the anti-addiction medication naltrexone for the treatment of extreme fatigue associated with long COVID. A January 2024 article in the journal Clinical Therapeutics, found that fatigue symptoms improved in patients taking the drug.
Al-Aly said doctors treating patients with long COVID are getting better at pinpointing the phenotype or manifestation of the condition and diagnosing a treatment accordingly. Treating long COVID fatigue is not the same as treating POTS or symptoms of headache and joint pain.
It’s still all about the management of symptoms and doctors lack any FDA-approved medications specifically for the condition.
