A seizure may be a major medical emergency where a patient loses consciousness, stares blankly or suffers dramatic convulsions.
Experienced by about one in 10 Americans at least once in their lifetimes, doctors often say the medical episode can be a stroke, brain infection or even high fever.
But now, Danish researchers are warning that they could be a sign of something much more sinister: Cancer and, in particular, brain cancer.
In a study on 49,900 Danish adults who had a first-time seizure, researchers revealed there were 5,600 cancer diagnoses.
Among these diagnoses, there were 966 detections of brain cancer — which was the most common cancer detected.
Analysis showed patients were four times more likely to be diagnosed with any cancer within a year of their first seizure compared to the general population.
For brain cancer, researchers said they were 76 times more likely to be diagnosed with the condition over the same period.
Sports teacher Glenn Colmer, 51, from the UK, was diagnosed with a brain tumor after he suffered a seizure at home. He died 10 days after the diagnosis. Beforehand, Colmer had suffered from aches and pains for a year that he thought were just due to aging
Overall, the vast majority of seizures analyzed in the paper did not lead to a diagnosis with cancer.
But the researchers still warned that, based on their results, a seizure should be treated as a potential warning sign of the condition.
Researchers warned that, in brain cancer, tumors can disrupt vital circuits and trigger a seizure.
For other cancers they found in participants in the study, including lung and colon, they said the disease could spread to the brain and cause a tumor to grow there, which could then also cause a seizure.
In the paper, published in JAMA Neurology, patients were 51.5 years old on average, and ranged in age at the time of their first seizure from 35 to 68 years.
Their seizures were recorded between 1996 and 2022.
Of the patients diagnosed with cancer after a seizure, brain cancer was the most common diagnosis.
Lung cancer was the second most common, with 843 diagnoses recorded in the study, followed by prostate cancer, 437 diagnoses, and colon cancer, 412 diagnoses.
A rising singer with a growing fanbase, Amber Woods, was diagnosed with pancreatic cancer at 25 years old about a year after she started to suffer from seizures
Other cancers also detected were breast cancer, urinary bladder cancer, melanoma, non-Hodgkin lymphoma, pancreatic cancer and kidney cancer.
The scientists, from Aarhus University, wrote in the paper: ‘First-time seizures were associated with a clearly elevated short-term relative risk and a slightly elevated long-term risk of neurological and non-neurological cancers.
‘These findings indicate that first-time seizures may serve as an early clinical sign of both neurological and non-neurological cancers.’
The researchers also found that from one to five years after their first seizure, participants had an 18 percent higher risk of being diagnosed with any cancer compared to the general population.
From five to 20 years, they had a 34 percent higher risk of a cancer diagnosis.
A seizure is abnormal electrical activity in the brain that triggers a change in awareness or muscle control.
There are two main types. One is generalized seizures, where both sides of the brain have a disruption, which triggers symptoms such as body shaking or staring.
The other type is a focal seizure, where a disruption in electrical activity occurs in just one side of the brain and causes symptoms that affect only one side of the body.
Researchers said a tumor in the brain could disrupt neural circuits, potentially causing a seizure (stock image)
Warning signs of a seizure include loss of consciousness, uncontrollable movements, staring, sudden emotional changes, drooling, abnormal eye movements or loss of bladder control.
It can occur at any age, but doctors say seizures are more likely to affect very young children and adults over 60 years old.
People particularly at risk from a seizure include those who have epilepsy, a condition affecting nearly three million people that triggers sudden abnormal activity in the brain.
Seizures are treated as a medical emergency the first time someone experiences them. Afterward, they may be considered an emergency if they cause someone to harm themselves and last for longer than five minutes.
Doctors may treat the condition by finding and treating the underlying cause. Patients may also be prescribed antiseizure medications or surgery to have a device implanted into their brain to help manage electrical activity.
