With several studies reporting that over 1/3rd of patients of COVID-19 show neurological symptoms, Dr Shradha Maheshwari, Head, Department of Neurosurgery, Dr RN Cooper Hospital reviews the neurological consequences of COVID-19 infections
Every pandemic brings along with it changes in every field. The COVID-19 pandemic has brought in similar changes in all fraternities of medicine. We all know that coronavirus manifests primarily in the lungs causing pneumonia however there is growing evidence that the virus invades other organs of the body like the eyes, heart, skin, kidneys and the nervous system. While we are still understanding this virus and trying to find a cure for this deadly disease, there now also seems to be a focus on how this virus is affecting other organs in the body. Several studies have now reported that over 1/3rd of patients of COVID-19 show neurological symptoms. Broadly the neurological and neurosurgical problems associated with coronavirus can be categorised into three main categories which are:
- Neurological affect due to coronavirus
The effect of coronavirus on the nervous system can be categorised into primary and secondary.
The coronavirus causes neurological disorders by directly infecting the brain or as a result of activation of the immune system. It has been suggested that as the infection enters through the nose, infection of the olfactory neurons may enable the spread of virus into the brain. The virus may sometimes enter from the respiratory tract to blood and then cross the blood brain barrier to enter into the brain to incite neurological symptoms. Some studies have also suggested that this virus causes intravascular coagulation which can then give rise to ischemic response in multiple organs including the brain.
The primary neurological manifestations occur due to direct infection of the central nervous system with the coronavirus. Whereas secondary manifestations can result from affection of other organs which indirectly affect the central nervous system.
The primary neurological manifestations can cause meningitis, encephalitis and seizures. Whereas dizziness, confusion, headache and stroke due to ischemia, hemorrhage or venous sinus thrombosis are secondary manifestations of coronavirus. Secondary manifestations are more commonly seen in patients with COVID-19, whereas primary manifestations occur in cases which are more severely infected.
Headache and loss of taste and smell are the most common symptoms seen in early stages of coronavirus infection. In advanced stages stroke, central venous thrombosis, hemorrhage and seizures are most commonly seen. In patients with severe hemorrhage and stroke causing pressure effect over the brain may need emergency neurosurgical procedures, to remove the clots or to relieve the brain of the swelling. This further subjects these patients to added stress of the surgery.
2. Effect of coronavirus on pre-existing neurological diseases
This pandemic not only bought physical illness along with it but it also led to a lot of mental stress and strain. This definitely had some effects on the pre-existing neurological diseases like migraine. Many people faced increased incidents of migraine even while sitting at home. People with neuromuscular disorders showed higher risk of pneumonia and required increased breathing assistance if infected. Patients with epilepsy showed an increase in frequency of convulsion. Some also had difficulty in mobility and cognition. Overall patients with neurological disorders were not only at high risk of getting infected with the virus but also showed more serious forms of infection once affected. Besides COVID-19 itself a lot of patients with neurological ailments could not seek appropriate medical follow ups and sometimes could not procure timely medicines subjecting them to increased attacks of their primary neurological disease itself.
3. Long term neurological effects of coronavirus
With improvement and recovery of patients from coronavirus it is now possible to study the long term neurological effect of coronavirus. A number of studies have shown residual changes in the brain on imaging as after effects of COVID-19. COVID-19 has been found to trigger Guillian Barre syndrome in which the patient may develop symptoms such as tingling, progressive leg weakness and facial weakness. Some patients have also shown increased incidence of stroke following COVID-19. Hypoxia during this infection affects multiple organs and in some cases permanent damage in the brain may leave the patient morbid with neurocognitive changes and seizures which may remain for lifetime.
While this infection has tormented people world over, those with added neurological problems either pre-existing or caused due to the infection, faced more severe consequences not only individually but also to their families. Some patients who needed neurosurgical intervention had to wait to get timely treatment due to the fear of this virus. With tele-consultation coming into the picture a lot of patients could seek some help however many still suffered and succumbed to the consequences. While this virus has already left its footprints in our minds, only time will tell how much and how long we will have to suffer its neurological consequences.