About 2.4% of adults with a first-time seizure are diagnosed with neurological cancer within a year, a JAMA Neurology study suggests — a rate 76 times higher than the general population.

It suggests that unexpected seizures may be an early warning sign, especially for metastatic cancer, said the researchers from Denmark’s Aarhus University, based on their study of 50,000 adults with no preceding cancer who had a first‑time hospital diagnosis of seizure.

“Primary brain cancers and metastases can induce seizures through structural disruption of neural circuits, peritumoural inflammation, elevated intracranial pressure, and increased excitatory neurotransmission,” they said.

“These mechanisms are likely to explain the markedly elevated short-term risk of brain cancers observed in our study.”