Stroke, Confusion, Loss of Smell & Taste: Other COVID-19 Symptoms

Experts are unclear if the virus can directly impact the brain or brain impairments are the results of blood clots.

Updated28 Apr 2020, 05:46 AM IST
Coronavirus
6 min read

"I felt confused and dizzy."

"I couldn't smell or taste anything."

Recovered COVID-19 patients from various parts of the world have shared their experience dealing with the virus and have spoken about such non-respiratory and early neurological symptoms. What's more worrying is one small subset of people who experienced strokes or anosmia and ageusia (loss of smell and taste respectively), and did not show any other respiratory symptoms.

Some studies and reports have also pointed out life-threatening brain complications due to coronaviruses such as encephalopathy, confusion, dizziness and seizures, and a few common but less damaging ones such as viral inflammation in the brain - encephalitis and meningitis - which have been reported in many other kinds of flu too.

Most people have registered shortness of breath, cough and fever as primary symptoms of COVID-19 but with new studies emerging about the neurological impact of the coronavirus in a small section of people, questions about what it means, whether or not loss of smell or taste are enough to self-isolate and how worrying it is, have risen.

Experts are unclear if the virus can directly impact the brain or brain impairments are the results of blood clots and body's immune system responding to the virus and then eventually harming itself in the brain. They also maintain that more number of peer-reviewed studies are needed to come to a conclusion on this subject.

Serious Manifestations on the Brain

A report from The Washington Post says that a lot of young patients with no history of any chronic condition and almost asymptomatic COVID-19 are getting strokes. A lot of them were at home when they got the stroke, unaware of their COVID-19 status.

The fact that the virus is impacting much more than just lungs, is making its mechanism a little difficult and ever-evolving. The number of cases with impact on the brain may not be very high right now, besides there is not enough definitive studies to invoke universal urgency - but some experts and reports in the US have started raising alarm.

Some experts suggest these strokes can be the result of blood clotting in the body which has been unusually widespread in coronavirus patients. The report also suggests that many patients suffered massive strokes, as opposed to mini-strokes.

The report further quotes Robert Stevens, a critical care doctor at Johns Hopkins Hospital who says, “We’ve also taken care of patients in their 30s with stroke and COVID-19, and this was extremely surprising,”

Another report from CNN quotes Dr. Thomas Oxley, Neurosurgeon, Mount Sinai Health System in New York saying, "The virus seems to be causing increased clotting in the large arteries, leading to severe stroke."

Apart from blood clotting, there is also some hypothesis about the virus attacking the central nervous system (CNS) directly.

One report by IIT experts explains the reasons for serious complications such as brain dysfunction and seizures. It says the receptor known as hACE2 (human angiotensin-converting enzyme-2) can be affected by the virus through the olfactory bulbs and also through other peripheral nerve terminals or simply blood circulation and may breach the blood-brain barrier to innervate and attack CNS causing encephalopathy called ANE.

Alarmingly, the scientists say this process may also completely destroy the medulla oblongata of the hindbrain, which regulates breathing, heart, and blood vessel function.

Patients of encephalopathy can look dazed, confused and lethargic according to experts.

An early report on Jama Network explores the complicated manifestations of coronavirus on the brain. This study involving 214 patients noted that 78 patients (36.4%) showed some kind of neurologic impact. It divides these manifestations in three broad categories namely, Central nervous system (CNS) involving strokes, dizziness, etc, peripheral nervous system (PNS) manifestations involving taste impairment, smell impairment, etc and skeletal muscular injury manifestations.

According to this study also, most neurologic manifestations occurred early in the illness and some patients without typical symptoms of COVID-19 came to the hospital with only neurologic manifestation as their presenting symptoms.

It further concluded,

"When seeing patients with neurologic manifestations, clinicians should suspect severe acute respiratory syndrome coronavirus 2 infections as a differential diagnosis to avoid delayed diagnosis or misdiagnosis and lose the chance to treat and prevent further transmission."

'COVID-19 May Affect the Central Nervous System'

Experts are divided on why lack of taste or smell is being observed in a lot of COVID-19 patients. Some suggest this could be because of virus' direct involvement with the nervous system and others maintain caution by waiting for more conclusive studies.

A research report published on Jama Network involving 202 COVID-19 patients concluded that 130 patients reported an altered sense of smell or taste. This amounts to nearly 64% of such cases. 27 of these patients reported severely affected sense of smell and taste and, 48 reported "As bad as it can be".

The report further says, "Alterations in smell or taste were frequently reported by mildly symptomatic patients with SARS-CoV-2 infection and often were the first apparent symptom."

With rising number of cases showcasing symptoms such as loss of smell and taste, it is imperative to understand how these appear and if these symptoms are enough to begin self-isolation.

Another recent study done by the scientists of the Indian Institute of Technology (IIT), Jodhpur has hinted that loss of smell and taste could be because of disturbance in CNS.

The paper written by Dr. Surajit Ghosh and his team which has been accepted in ACS Chemical Neuroscience and supported by Science & Engineering Research Board (SERB), a Statutory Body of the Department of Science & Technology (DST) says,

"Nose and mouth both are very important entry points of the virus, which then may be slowly making its way to the olfactory bulb using the neurons of the olfactory mucosa. The olfactory bulb located in the forebrain is the structure that is chiefly responsible for the sense of smell."

The New York Times quoted Claire Hopkins, Professor of Rhinology at King's College, London saying anyone who develops loss of smell and taste should self-isolate.

"Experts in rhinology have suggested that the onset of such symptoms could either act as a trigger for testing for the disease where possible, or could be a new criterion to self-isolate", says a report co-published by Prof Hopkins.

However, Dr Anshu Rohatgi, Senior Consultant, Neurology Department at Sir Ganga Ram Hospital, Delhi doesn't agree. He tells FIT, "Just the loss of taste and smell is not good enough reason to self-isolate. These symptoms are commonly seen in other influenza and flu for various reasons."

He, however, maintains that anosmia and ageusia are due to neurological involvement. He says,

"COVID-19 virus doesn't cross the Central Nervous System so even though both loss of taste and smell are neurological implications, we don't yet know the exact reason for this. it's not direct implication."
Stroke, Confusion, Loss of Smell & Taste: Other COVID-19 Symptoms

'Virus May Not Attack Brain Directly'

FIT reached out to Dr Manjari Tripathi, Professor of Neurology at AIIMS to understand why these brain implications are being seen. She told us, "There are two ways in which COVID-19 can impact the brain - Direct involvement of the virus with the brain or vessels and immunological implications but a lot of work still needs to be done on this. Both of these mechanisms are, however, possible."

She also adds, "Loss of smell is a very prominent feature of COVID-19 infection. This can actually be the beginning manifestation of COVID-19, it has been well documented."

Dr Anshu Rohatgi tells FIT,

"Encephalopathy is another common neurological implication of COVID-19. It can occur because of inflammatory changes in the body. A report from New York says that patients of less than 50-year-old age have large incidents of vessel involvement leading to strokes."

Only a little is known about such complications so far, thus, to draw conclusions would be premature. However, experts do believe it's a matter of concern, thus needs more research. The way people are conscious and aware of their breathing and coughing, they can also show same emergency for mental symptoms to avoid any potential danger.

Dr Sumit Ray, Critical Care Expert told FIT, "All serious viral respiratory illnesses can have a neurological complication in terms of encephalopathy and due to blood clotting in the blood vessels. So there is a potential risk of strokes. There is also a chance of long term cognitive dysfunction for extremely serious cases."

He further added,

"The brain directly doesn't get affected by the virus in this case. It is not known how exactly the brain is impacted at certain centers by the virus but there is a possible hypothesis."

He explains how our immune response to any virus is complex. So when the virus enters our body, gets attached to cells and create proteins - in the process they enter lots of cells. Among the many effects, blood vessels is very common leading to stroke, lack of oxygen, etc.

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Published: 27 Apr 2020, 08:28 AM IST

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