New research suggests that a headache could be one of the key symptoms of COVID-19 infection, which could further predict the clinical evolution of the disease in patients.

A study, conducted on more than 100 patients, found that headache could occur during the asymptomatic or early symptomatic phase of COVID-19, which could resemble migraine headache or tension-type headache.

Previous studies have revealed that COVID-19 could affect the entire nervous system, causing symptoms such as headaches, dizziness, anosmia (loss of sense of smell), and ageusia (loss of taste), which were associated with a shorter hospitalization period.

Researchers found that some patients experienced headaches even after the other symptoms of coronavirus resolved.

The researchers noted that understanding the pathophysiology of this particular symptom could help in understanding migraine and other types of headaches.

Lead author Dr. Patricia Pozo-Rosich of Vall d’Hebron University Hospital, Barcelona, Spain, told Medscape Medical News, “It seems that those patients who start early on, during the asymptomatic or early symptomatic period of COVID-19, with headache have a more localized inflammatory response that may reflect the ability of the body to better control and respond to the infection by SARS-CoV-2.”

Experts have explained that the virus penetrates the cells through angiotensin-converting enzyme 2 (ACE2), which is found in several cells and tissues.

Dr. Pozo-Rosich said, “SARS-CoV-2 enters the body through the nasal cavity and it probably penetrates the nervous system in the periphery through afferent branches of the olfactory and trigeminal nerve.”

The virus travels to the lungs and later enters the bloodstream, crossing the blood-brain barrier to affect the nervous system. During this process, there is an intense immune response, generating systemic inflammation and causing a cytokine storm.

The researchers looked at 130 patients with COVID-19 who were seen by neurologists at Vall d’Hebron, of which, nearly 75 percent had a headache, and about 38 percent of these patients had a persistent headache after six weeks, suggesting that some patients may develop a new type of headache.

The author also noted that most treatments, including ibuprofen, candesartan, and anti-CGRP monoclonal antibodies, are safe for managing headaches in COVID-19.

Dr. Pozo-Rosich said, “We should just try to initially avoid steroids to avoid interference with the body’s reaction to SARS-CoV-2.” The article originally appeared on Medscape Medical News.