Though primarily a respiratory disease, the coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), can lead to a variety of symptoms.
The hallmark symptoms of the illness include cough, fever, and difficulty of breathing. However, some people develop other symptoms such as headaches, body pain, diarrhea, loss of smell, and taste, among others.
Researchers at the Hospital Universitario de La Princes in Madrid, Spain, found that patients with COVID-19 who developed headaches as an early symptom of infection had a milder illness and less risk of death.
Headache and COVID-19
Headache is a common symptom in people infected with SARS-CoV-2, with a prevalence ranging between 13 percent and 74.6 percent. Past studies have also noted that headache usually happens early throughout the illness, and has been tied to a loss of smell and taste.
Further, it has been revealed that SARS-CoV-2 has a neuroinvasive potential. In a few patients, SARS-CoV-2 has been detected in the cerebrospinal fluid, a clear, colorless body fluid found in the brain and spinal cord.
SARS-CoV-2 can also trigger a cytokine storm, a phenomenon where the body’s own immune response starts to attack its own cells and tissues. When this happens, cytokines can invade the brain and be involved in the systemic response after being subjected to hypoxemia.
Despite these, SARS-CoV-2’s neuroinvasive potential remains unclear. It also remains unknown the real link between COVID-19 and the development of headache.
Hence, the researchers aimed to “identify factors associated with headache in COVID‐19 and headache characteristics.”
The study, published in the European Journal of Neurology, involved hospitalized COVID-19 patients with pneumonia in March 2020. The case-control study involved two groups, those with COVID-19 with headache and controls that comprise COVID-19 patients without headache.
The researchers obtained a complete medical history from each patient, noting demographic and clinical data, including age, sex, date of symptom onset, clinical manifestations, and Charlson comorbidity index.
They also recorded and evaluated laboratory results such as leukocyte count, lymphocyte count, C-reactive protein, creatinine, lactate dehydrogenase, and urea. Radiologic features were also included.
The researchers also included the characterization of headaches during the course of the infection. Neurologists interviewed the hospitalized patients with headache using a semi-structured questionnaire that included prior history of headache, sociodemographic variables, onset, duration, frequency, and intensity of attacks according to the International Headache Society (HIS) system. Other factors like pain localization and type, and the presence of other related symptoms such as vomiting, nausea, and photophobia were also noted.
Of the 379 COVID-19 patients, 13 percent developed a headache. Of these, 62 percent were men, and the average age was 57. The team has found that younger people and those with fewer comorbidities were more likely to develop a headache.
Further, headache has been associated with reduced mortality or death, low levels of C-reactive protein, which is a sign of inflammation in the body, mild acute respiratory distress syndrome (ARDS), a complication of COVID-19, and oropharyngeal symptoms.
Among the symptoms of SARS-CoV-2 infection, pharyngitis or sore throat, loss of taste, joint pain, nausea, and vomiting were more common in patients with headache.
According to our results, migraine and tension-type headache were the most prevalent primary headaches in COVID-19 patients,” the researchers noted in the paper.
The results showed that headaches are an important symptom of COVID-19, affecting 13 percent of patients. Hospitalized COVID-19 patients who are younger and have no comorbidities, including hypertension, are more likely to develop a headache during the infection. This indicates that headache may manifest in patients with healthier backgrounds, suggesting that a healthy immune system may have a role in the development of headache during COVID-19 illness.
Our results show that mild inflammation and mild respiratory failure could play a role in the development of headache during COVID-19,”
The researchers added that recognizing COVID-19-linked headache may help healthcare providers improve clinical management and treatment of COVID-19 patients.