Severe seizure events found to be common in Angelman patients

Researchers highlight need to correctly ID and treat symptoms

Marisa Wexler, MS avatar

by Marisa Wexler, MS |

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A doctor uses a stethoscope to examine a child being held by an adult.

Severe seizure events known as status epilepticus are common in people with Angelman syndrome, especially during childhood, a new review study found.

Researchers noted that status epilepticus often causes subtle symptoms that may be overlooked by caregivers and clinicians, highlighting the importance of correctly identifying and promptly treating these severe seizure events.

“Further studies are needed to precisely characterize the clinical features, treatment options, and outcomes of [status epilepticus] in these patients,” the team wrote.

The study, “Status Epilepticus in Chromosomal Disorders Associated with Epilepsy: A Systematic Review,” was published in the journal Genes.

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Severe seizure events most common in childhood

Status epilepticus, or SE, refers to seizures that last more than five minutes, or having more than one seizure within five minutes without the person regaining conscious. SE is a medical emergency that is often life-threatening. However, there are no specific treatments available for patients with Angelman or other genetic diseases who experience these seizures.

Now, a team of scientists in Italy sought to learn more about what is known regarding SE in Angelman and other genetic disorders that are characterized by seizures. To that end, they conducted a review of the published scientific literature on the subject.

The review included 20 studies that focused on Angelman, reporting data on 149 patients who experienced SE. Half of the reports described Angelman patients who experienced multiple recurring episodes of status epilepticus. 

Reported cases of SE appeared to be most common during infancy and childhood for individuals with Angelman, with some studies suggesting that these severe seizure events become less common as patients get older, particularly after puberty.

“This is consistent with the typical modifications in the epilepsy pattern these patients go through over time, leading to an increase in the proportion of patients that reach seizure freedom after puberty,” the researchers wrote.

Most SE events were classified as nonconvulsive status epilepticus (NCSE), meaning that the seizure manifested with symptoms of altered mental state, but not body convulsions. Treatment for SE generally followed international guidelines, with first-line therapy using benzodiazepines and second-line therapy using anti-seizure medications.

Understanding the clinical features of [seizures with altered mental state] and providing adequate treatment are crucial steps in the care of patients with [Angelman].

Because most of the studies were case reports or series — detailed descriptions of outcomes for one patient or a group of patients — the team was unable to draw meaningful conclusions about exactly how common SE is for people with Angelman. They also noted that, especially for NCSE, symptoms might be subtle and may not always be detected by caregivers and clinicians.

“Most patients with [Angelman syndrome] experienced singular or recurrent NCSE episodes, which often represent a diagnostic challenge due to their subtle or absent clinical features,” the researchers wrote.

The team noted that people with Angelman typically exhibit a happy demeanor marked by prominent smiling, laughing, “general exuberance” and hyperactive behaviors.

“The interruption of this typical pattern, with the appearance of motor clumsiness, drooling of saliva, dulling of responsiveness and [drowsiness] … may suggest the occurrence of NCSE,” they wrote.

Stressing that untreated SE events can cause neurological damage with long-term consequences, the researchers said that “understanding the clinical features of NCSE and providing adequate treatment are crucial steps in the care of patients with [Angelman].”