After contracting Covid-19, 44-year-old Ms. Lien struggles with vocabulary, frequently having difficulty finding the right words or misnaming objects, such as confusing “scissors” with “knife.”
Not long after recovering from Covid-19, Ms. Lien often experiences headaches, insomnia, feelings of confusion, and memory loss as she struggles to remember the names and locations of everyday items. At times, she forgets things she has done and even the names of her family members. While reading, there are passages she doesn’t understand. Consequently, she has started to find communication challenging as she cannot express her thoughts clearly, and cooking has become more time-consuming as she cannot concentrate like she used to.
Her mood has also changed; she often feels frustrated, anxious, and experiences palpitations. She becomes easily irritated when her memory issues disrupt her daily life. “I feel like an old person,” she told her doctor.
Dr. Nguyen Huy Hoang (a specialist in treating autonomic nervous system disorders at the Vietnam-Russia High-Pressure Oxygen Center, Ministry of Defense), who directly consulted on this case, stated that the patient is experiencing “brain fog,” a common post-Covid-19 symptom. “Brain fog” refers to symptoms associated with cerebral hypoperfusion and autonomic nervous system disorders, affecting thinking and memory. Those affected may feel mentally unclear, have difficulty concentrating, take longer to remember someone’s name, or suddenly forget what they intended to do…
Dr. Hoang is also treating Mrs. Nhung, 67, who has a history of hypertension and is also experiencing “brain fog.” After recovering from Covid-19, she tries to do household chores but suffers from prolonged aches and fatigue. During many conversations, she often has to pause because she doesn’t know how to continue, repeating her words. Patients frequently place objects in unusual locations, misplacing items and unable to find them again.
On average, Dr. Hoang receives 50-60 calls related to Covid-19 daily, with 15-20% of them being patients suffering from “brain fog.” This phenomenon occurs in both the elderly and younger individuals, in both severe and mild cases, often appearing while infected with Covid-19 or a few days after recovery.
Doctors treating and caring for patients at the Covid-19 Resuscitation Center in Ho Chi Minh City Oncology Hospital (Thu Duc City), September 2021. (Photo: Quynh Tran)
“Brain fog” remains a mystery to the medical community due to the wide variety of symptoms. The condition of “brain fog” post-Covid seems to be more common among middle-aged patients with underlying conditions such as diabetes and hypertension.
Dr. Hoang noted that besides common symptoms like decreased concentration, reduced mental clarity during work, and memory impairment, the condition is associated with various systemic symptoms, not just one part of the body. For instance, patients may experience rapid heartbeat, palpitations, occasional shortness of breath, muscle spasms, and trembling hands and feet. Some symptoms of “brain fog” include headaches, dizziness, insomnia, psychological disorders, sensory disturbances, and motor disorders like finger tremors…
The causes of “brain fog” may relate to the invasion of the virus into nerve tissues and cells, along with widespread inflammation (including the nervous system) resulting from Covid. “Brain fog” is also believed to stem from anxiety and stress, leading to poor sleep and excessive rumination, affecting mood and behavior. Additionally, during the infection, blood vessels, especially small vessels, may be damaged post-Covid-19, reducing blood flow to the brain, which exacerbates the condition of “brain fog.”
In severe patients, oxygen deficiency can affect brain tissues, leaving behind the symptom of “brain fog.” Furthermore, other causes may include the side effects of sedatives and medications used in intensive care for severe patients.
Some studies worldwide suggest that after a Covid-19 infection, individuals’ immune responses remain persistently activated, which may cause inflammation in blood vessels or cells. Released inflammatory molecules can become toxic, particularly to the brain, leading to the phenomenon of “brain fog.” Another hypothesis is autoimmune conditions, where antibodies mistakenly attack nerve cells. Symptoms like numbness and tingling in the limbs may occur when nerves are damaged, sending incorrect signals to the brain. Some individuals with “brain fog” still experience heart and lung issues, worsening neurological symptoms.
The condition of “brain fog” will gradually improve over several months, but it may recur with triggering factors or excessive stress. Patients are advised to engage in light exercise to help clear their minds, play games like puzzles or listen to music to stimulate brain activity, and consume foods rich in Omega-3 and antioxidants to alleviate “brain fog.” Dr. Hoang recommends that those experiencing “brain fog” seek early medical consultation to rule out other conditions and address neurological issues. The most effective way to limit the impact of Covid-19 remains vaccination and adherence to preventive health guidelines.
* Names of individuals have been changed.
