Low risk for first-ever seizure in incidental CCM

Dr. Halley Alexander and Dr. Abel Sandmann discuss seizure rates and risk factors in patients with cerebral cavernous malformations (CCMs) during long-term follow-up without CCM intervention.

Show citation:

Sandmann ACA, Vandertop WP, White PM, Verbaan D, Coutinho JM, Al-Shahi Salman R. Seizures and Epilepsy in Patients With Untreated Cerebral Cavernous Malformations: A Prospective, Population-Based Cohort Study. Neurology. 2025;105(11):e214387. doi:10.1212/WNL.0000000000214387

Show transcript:

Dr. Halley Alexander:

Hi, this is Halley Alexander with today's Neurology Minute. I'm here with Abel Sandmann from Amsterdam University Medical Center, and we just finished recording a full-length podcast about some exciting findings related to cerebral cavernous malformations and the risk of seizures and epilepsy.

Abel, can you give our listeners a rundown of the most exciting findings and how it can change practice?

Dr. Abel Sandmann:

In our paper, we show that patients with a cerebral cavernous malformation who have a first unprovoked seizure should be diagnosed with epilepsy and considered for anti-seizure medication, as most of them achieve long-term seizure freedom with medical therapy alone.

These findings are based on a prospective population-based cohort study in which we analyze long-term follow-up and assess the rates and risk factors for: one, a first-ever epileptic seizure; two, seizure recurrence to evaluate the updated ILAE definition of epilepsy; and three, seizure freedom over two years and five years among patients with epilepsy.

We found that among patients who had never experienced a seizure before, the 10-year risk of a first-ever seizure was only 6%. This supports current recommendations against prophylactic anti-seizure medication in patients who are incidentally diagnosed with a cerebral cavernous malformation. However, following a first unprovoked seizure, the 10-year risk of recurrence was 80%, which exceeds the 60% threshold defined by the ILAE.

This justifies diagnosing epilepsy after the first and provoked seizure in this population. Given that the risk of recurrence was lower in patients treated with anti-seizure medication after the first seizure, this supports early initiation of therapy, although these treatment analyses were non-randomized and should be interpreted cautiously. Most patients who met the definition of epilepsy became two year and five years seizure-free with medical management alone.

But some patients with cerebral cavernous malformations develop medically intractable seizures and might benefit from surgical treatments.

Dr. Halley Alexander:

Excellent. Thank you so much, Abel. You can find the full-length podcast, which is available now on the Neurology Podcast, or you can also find the full article in Neurology at neurology.org, or in the December 2025 print issue.

As always, thanks for tuning in for today's Neurology Minute.