Obstructive sleep apnoea (OSA) is an under-recognised comorbidity in epilepsy. Repeated upper-airway obstruction during sleep causes intermittent oxygen reduction, repeated arousals and fragmented sleep.
Because sleep and epilepsy strongly influence one another, untreated OSA can be clinically important even when the person does not complain of classic daytime sleepiness.
What happens in obstructive sleep apnoea?
During sleep, the upper airway repeatedly narrows or closes while breathing effort continues.
Episodes can cause snoring, gasping, oxygen desaturation and brief arousals that the person may not remember.
Why OSA matters in epilepsy
Sleep deprivation and sleep fragmentation can lower seizure threshold in susceptible people.
Intermittent hypoxia, autonomic activation and cardiovascular stress may also contribute to a less favourable neurological environment.
The relationship may run both ways
People with epilepsy may have increased OSA risk because of weight change, sedating medicines, reduced activity, craniofacial factors and age-related risk.
Recent research also examines whether sleep apnoea contributes to seizure burden or to the development of late-onset epilepsy.
Symptoms
Possible clues include loud habitual snoring, witnessed pauses in breathing, choking or gasping in sleep, morning headache, dry mouth, unrefreshing sleep, nocturia, daytime sleepiness, poor concentration and irritability.
Not everyone has all of these symptoms.
Nocturnal seizures can look like sleep apnoea—and vice versa
Gasping, abrupt awakening, movement and confusion can occur in both sleep-disordered breathing and nocturnal seizures.
Video-EEG, polysomnography or combined studies may be required when the events are unclear.
Diagnosis
OSA is diagnosed using sleep testing that measures breathing disturbance during sleep.
Depending on the person and healthcare system, this may involve laboratory polysomnography or an appropriate home sleep-apnoea test.
Screening questionnaires
Tools such as STOP-BANG can identify higher-risk individuals but cannot diagnose OSA.
Epilepsy clinics increasingly recognise the value of routine sleep screening because symptoms are easily missed.
Does treating OSA improve seizures?
Observational studies suggest that effective treatment—particularly continuous positive airway pressure (CPAP)—may improve seizure control in some people.
A 2026 critical review concluded that OSA should be viewed as a potentially modifiable risk factor in epilepsy while also noting that stronger randomised evidence is still needed.
CPAP
CPAP keeps the airway open by delivering positive pressure through a mask during sleep.
Benefit depends strongly on consistent use, correct mask fit and adequate pressure settings.
Other treatments
Management may include weight reduction when appropriate, positional therapy, mandibular advancement devices, treatment of nasal obstruction or selected upper-airway surgery.
The appropriate approach depends on OSA severity and individual anatomy.
OSA and SUDEP
Researchers are studying whether sleep apnoea may contribute to physiological risk factors associated with sudden unexpected death in epilepsy.
The evidence does not establish OSA as a direct cause of SUDEP, but nocturnal hypoxia, autonomic disturbance and breathing abnormalities make the relationship clinically important to investigate.
Central sleep apnoea
Central sleep apnoea is different: breathing effort itself temporarily decreases or stops because of altered respiratory control.
It should not be confused with the much more common obstructive form.
Medication and sedation
Sedating medicines, alcohol and some other substances can worsen sleep-disordered breathing in susceptible people.
Medication review should therefore form part of a broader sleep assessment.
Children
Paediatric OSA may present through snoring, restless sleep, behavioural change, concentration problems or growth difficulties rather than obvious daytime sleepiness.
Enlarged tonsils and adenoids are important causes in children.
The central point
Sleep apnoea is treatable and may worsen several factors relevant to epilepsy, including sleep quality, cognition and possibly seizure control. Persistent snoring, witnessed apnoeas or unexplained daytime sleepiness deserve assessment rather than being assumed to be “just epilepsy”.
Related reading
Sleep & Epilepsy →
Sleep-Related Hypermotor Seizures →
SUDEP — Straight Facts →
Sources
Evidence checked: September 2026.