The Epilepsy Foundation said the tweets, which contained "flashing or strobing lights," were targeted at the foundation's account and hashtags as they promoted National Epilepsy Awareness Month.
A group fighting epilepsy in the United States has filed a criminal complaint after its Twitter account was barraged with images that could cause seizures in epileptics.
The Epilepsy Foundation said on Monday the tweets, which contained "flashing or strobing lights," were targeted at the foundation's account and hashtags as they promoted National Epilepsy Awareness Month, and could have induced seizures in the minority of epileptics vulnerable to such images.
"While the population of those with photosensitive epilepsy is small, the impact can be quite serious. Many are not even aware they have photosensitivity until they have a seizure," Jacqueline French, chief medical and innovation officer of the Epilepsy Foundation said in a statement.
Exposure to "flashing lights at certain intensities or certain visual patterns," can trigger seizures in about three percent of epileptics suffering from photosensitive epilepsy, the foundation said.
"These attacks are no different than a person carrying a strobe light into a convention of people with epilepsy and seizures, with the intention of inducing seizures and thereby causing significant harm to the participants," the foundation's director of legal advocacy Allison Nichol said.
In 2017, 29-year-old John R. Rivello was arrested on federal charges that he intentionally tweeted a blinding strobe light at journalist Kurt Eichenwald, who has openly discussed his epilepsy and is also a critic of President Donald Trump.
Eichenwald had a seizure, and was found on the floor of his office by his wife.
The New York Times reported Rivello would plead guilty to aggravated assault at a court hearing set for January.