Headache in Covid

Headaches in Covid

Introduction

Headache refers to the pain above the foramen magnum of the skull and frequently neck pain is associated. Globally, the prevalence of headache in the general population is 47%, and the lifetime prevalence is more than 66% & up to 80% in some studies. It is told that it is difficult to find an old person who never had any headaches in his life. Headache is a burden to society with reduced quality of life and disability.

Headache is a very common clinical symptom with a systemic infection like viral fever, and therefore the infection with the Covid it is an exception. Among many pain symptoms in Covid and post Covid period headache is one important pain symptom. During a recent retrospective case study, during which Guan et al analyzed data from 1590 patients with COVID-19 in China between 11 December 2019 and 31 January 2020, the incidence of headache was 15.4%. In another study, 205 patients were suffering from headaches in 1328 patients of covid. In a report in Australia, 36% reported headache amonsgt 6394 confirmed cases. Some patients had other neurological symptoms, like dizziness, nausea, and vomiting along with headache.

Why there is headache in Covid?

The mechanism of headache in Covid is not clear. There are many hypothesizes. Following may be some possible reasons:

• The cytokine levels within the serum of patients with Coronavirus infection were elevated. These are tumor necrosis factor, interleukin 2, and granulocyte macrophage-colony stimulating factor, etc. These cytokines may cause headaches.
• When Coronavirus invades tissues of the lung, it’s going to cause ventilation-perfusion mismatch –> alveolar gas exchange disorders –> resulting in hypoxia within the brain –> increasing the anaerobic metabolism of mitochondria in nerve cell –> accumulation of acid metabolites. This causes abnormalities of cerebral blood flow –> swelling of brain cells –> cerebrovascular dilatation –> headache due to ischemia and congestion.
• Coronavirus transmission normally invades through droplet infection through the mouth and nose. The virus can be transmitted to the brain through different neural networks in the nose and mouth and infect the brain.
• The presence of blood and lymphatic capillaries within the nasal mucosa provides a positive environment for the virus invasion and help to enter the bloodstream after interaction with ACE2 expressed on endothelial cells. When the virus spreads within the tract, it also can bind to ACE2 expressed on the epithelial cells and enter the bloodstream. Coronavirus can spread to the CNS through vascular pathways. Likewise, the virus within the GI tract also can enter the CNS through cranial nerves like Vagus, blood vessels, and lymphatic pathways.

Patient of Covid may present with headache without fever

Fever is the commonest symptom in patients with Covid, but sometimes headache or muscle pain can be the first symptom. It has been noticed in some patients that fever is not there at all. After headache other symptoms are anosmia, abdominal pain, and hypoxemia. So if a patient has been exposed to other covid patients and develops sudden and unusual headache covid must be suspected. 

What should be done if you have headaches in the covid era?

• Must not be too anxious, headache is common with any systemic infection and resolves spontaneously.
• Choose a dark room for rest, avoid sounds during headache attacks
• May take paracetamol.
• Avoid bright lights, watching TV, mobile or laptop for longer time
• If the headache is more than mild, persists, or increases, or associated with some neurological symptoms like numbness, weakness, convulsions, visual symptoms, unconsciousness the patient must consult a doctor.
• Headache & other types of pain management in Covid patients is challenging.

References:

1. Guan WJ, Liang WH, Zhao Y, et al. Comorbidity and its impact on 1590 patients with Covid-19 in China: a nationwide analysis. Eur Respir J. 2020;55:2000547
2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7273035/
3. Weng LM, Su X, Wang XQ. Pain Symptoms in Patients with Coronavirus Disease (COVID-19): A Literature Review. J Pain Res. 2021;14:147-159
4. Neurath MF. Covid-19 and immunomodulation in IBD. Gut. 2020;69:1335–1342