Rare Seizures During Sleep Identified for 1st Time in Child With PWS
Researchers have documented the first case of a rare condition characterized by neurocognitive regression and epileptic seizures during sleep in a child with Prader-Willi syndrome (PWS).
Their case report, “Electrical status epilepticus during sleep in a child with Prader-Willi syndrome: a case report,” was published in the journal AME Case Reports.
Sleep disorders are common in PWS, and sleep studies are routinely performed to monitor for sleep apnea — when breathing repeatedly stops and starts during sleep — before the start of growth hormone therapy, a standard treatment for PWS.
People with PWS also have an increased risk of several types of seizure disorders, which are usually treated successfully with anticonvulsant medications.
Electrical status epilepticus in sleep (ESES) is a rare sleep-related seizure disorder with symptoms including multiple seizure types during sleep, behavioral problems, and motor impairments. Seizures usually emerge between the age of 3 and 5, and remit spontaneously around puberty.
ESES can be diagnosed with an electroencephalogram (EEG) recording, which looks at the brain’s electrical activity.
In this case report, a girl had been diagnosed with PWS at 8 weeks old and started growth hormone therapy at 3 months. During an appointment at Western Michigan University to restart the therapy at age 5 (after her parents had decided to stop the treatment), a physical exam revealed that she was thin and anxious, but otherwise developmentally normal. Her mother reported that she was often restless during the day, but with no symptoms suggestive of sleep disordered breathing.
In a sleep study, an EEG revealed that the girl took longer than normal to fall asleep — 74 minutes — but had otherwise normal sleep for her age. She experienced a few respiratory events, including apnea, but had overall normal oxygen levels.
However, during the recording, the EEG began to show abnormal electrical spikes, indicating she was having a seizure, although no abnormal body movements were apparent.
This abnormal EEG activity was only seen while the child was asleep — her waking EEG was normal. A neurologist determined that the specific pattern of electrical activity occurring in certain phases of her sleep cycle was consistent with an ESES diagnosis.
The patient did not return for follow-up, and no treatment for ESES was initiated.
The child had shown no signs of cognitive problems, the researchers noted. “It is possible, however, that mild seizure episodes such as staring or abnormal movements may have been missed by the family,” they wrote.
ESES is associated with variable outcomes, and the early start of treatment can help to prevent more seizures and cognitive problems later on.
“Since timely diagnosis and early treatment of ESES is very important to prevent neurocognitive decline, we are hoping that our case may raise awareness of this condition,” the researchers concluded.