COVID-19 complications, rare vaccine side effects, brain parasites: Inside 2022's most-read medical case reports

People are shown outside a COVID-19 testing site in Montreal, Saturday, January 15, 2022, as the pandemic continues in Canada. THE CANADIAN PRESS/Graham Hughes

Even three years into the pandemic, COVID-19 is still top of mind, dominating the most-read medical case reports for 2022, ranging from unusual side effects caused by the disease itself to rare adverse reactions to vaccines.

BMJ Case Reports, a scientific journal that focuses on publishing case reports, provided CTVNews.ca with a list of the top 10 most-read case reports as of Dec. 1, giving an insight into which medical curiosities and questions were most of interest to readers and scientists this year.

As opposed to studies, which have a wider pool of participants, medical case reports provide an in-depth description of one patient’s illness or disorder, usually one that is rare or challenges our existing understanding of a certain medical issue.

Along with COVID-19 complications and vaccine side effects, brain parasites and cycling made an appearance in the top 10.

Here's a roundup of the most-read case studies from the BMJ Case Reports in 2022:

COVID-19 CAUSING PERICARDITIS

The number one most-read case report, published in January, revolved around COVID-19 presenting in a patient purely through cardiovascular symptoms, with none of the regular flu-like symptoms.

It started when a 56-year-old reported feeling sudden chest pain, which was mild for around a day before gradually increasing in severity. Along with the pain was an “uneasy sensation” — according to the case report, he described the left side of his chest over his heart feeling strange, a sensation which increased with exertion, lying flat and breathing deeply. However, he had no cough or fever, and no other family members were experiencing similar issues.

Something that made diagnosis even harder was that he had normal cardiac biomarkers. Based on the chest pain, he was diagnosed with pericarditis, which is a swelling of the thin tissue that surrounds the heart. While conducting numerous other tests, which failed to find a cause, doctors had the patient take a PCR test, which came back positive for COVID-19.

The patient improved rapidly with treatment through aspirin and was discharged in stable condition after five days with instructions to isolate for two weeks. The case report concluded that COVID-19 had to be the source of the pericarditis, since all other causes had been ruled out. The authors noted that although COVID-19 is known to affect the cardiovascular system, it’s still very rare to have the disease manifest purely through chest pain with no issues with the heart’s rhythm or the lungs.

CHILD STRUCK WITH GBS AFTER COVID-19 INFECTION

A case in which a child presented with the rare Guillain-Barre syndrome (GBS) in connection with a case of COVID-19, and then slowly recovered without pharmaceutical treatment, made up the second most-read report, which was published in March.

GBS is a rare, debilitating illness in which the immune system causes damage to the nerves, causing muscle weakness and even paralysis. It’s usually associated with a previous infection, usually a respiratory or gastrointestinal infection. Adult patients have developed GBS after a COVID-19 infection, according to the case report, but there have been few documented cases among children.

In this instance, a nine-year-old was presenting with difficulty walking, back pain and weakness in his lower limbs. Doctors monitored him during a hospital stay, but focused on physiotherapy instead of medical treatments that might be given to those with more severe cases of GBS. He is still recovering, and is set to be followed up for the next year to see if all of his mobility returns.

STABLE GOITER FOR YEARS THEN GRAVES DISEASE

COVID-19 remained the dominating theme in the third most-read case report as well, with this one focusing on the rare case of a severe adverse reaction after receiving the second dose of a COVID-19 vaccine.

This case report, which was actually published in December 2021, followed a 71-year-old woman with a history of Stage 4 breast cancer who presented with Graves’ disease following her second dose of the Pfizer-BioNTech vaccine.

Graves’ disease is another disorder related to the immune system — this one results in the overproduction of thyroid hormones, which can cause a range of symptoms including bulging eyes, swelling around the thyroid gland in the throat, weight loss, fatigue and anxiety, among others.

This particular patient had previously undergone biopsies related to hyperthyroidism due to a goiter she had, something which usually signals thyroid issues. Those previous investigations had concluded the goiter wasn’t malignant.

According to the case report, she is now stable, and is the fifth known case of this COVID-19 vaccine being associated with the onset of Graves' disease.

The authors noted that adverse events are inevitable with a vaccine rollout of this magnitude, but that these reactions are rare.

More than 95 million doses of COVID-19 vaccines have been administered in Canada alone since December of 2020, according to the Public Health Agency of Canada.

PARASITES IN THE BRAIN

Seizures in adults can be caused by conditions such as epilepsy, or certain diseases such as meningitis, but a lesser known cause is parasites, which reared their heads in the fourth most-read case report of 2022, published in March.

In the most-read case that didn’t involve COVID-19, a woman in her 30s sought medical help for a series of seizures, protruding eyes and swellings in her face and tongue which had persisted over a period of three years.

The cause? The larvae of a tapeworm known as Taenia solium, which had infected the brain and other muscles in the soft tissue of the face, including the tongue, an affliction known as cysticercosis.

RARE VACCINE REACTIONS AND MORE

Rounding out the top five of the most-read case reports in 2022 was another rare case of an adverse reaction associated with a COVID-19 vaccine, with an 82-year-old woman presenting with abdominal pain within 21 days of receiving the AstraZeneca vaccine. This case report, like the third most-read one, was published in December of 2021.

The source was discovered to be blood clots blocking a key blood vessel to the spleen, resulting in the tissue slowly dying. Called a splenic infarct, it’s a very rare medical issue, according to the case report, with one estimate finding that its prevalence is as low as one case out of 125,000 people per year. The report stated that the woman’s reaction was classified as a life-threatening adverse event, and was reported to health authorities.

The woman is currently making a “very good recovery,” the report stated, and chose to receive the second dose of AstraZeneca with no negative reactions.

Number six on the list, published in January, also told the story of a woman who experienced a type of blood clots called vaccine-induced immune thrombotic thrombocytopenia (VITT) after receiving Dose 1 of the AstraZeneca vaccine.

AstraZeneca is approved in Canada, but the risk of blood clots caused Canada to shift away from recommending it in 2021.

Clarkson’s disease, a potentially fatal disorder also called systemic capillary leak syndrome, showed up in the seventh most-read case report, published in March. This exceedingly rare condition is characterized by fluid and proteins leaking out of tiny blood vessels into the surrounding tissues.

In the case report, a woman in her 40s presented with Clarkson’s disease four days after the second dose of the Pfizer-BioNTech vaccine, which would make her only the second person in the world thus far to experience Clarkson’s disease as an adverse reaction to the Pfizer vaccine, authors noted.

The last three case reports on the list described a case of a man in his 80s developing haemophilia after receiving the Pfizer-BioNTech vaccine, a middle-aged woman sustaining a seizure for a full hour due to COVID-19 attacking the tissues of her brain, and a 75-year-old male cyclist experiencing cardiovascular issues that were interfering with his quality of life.