Epilepsy and sleep apnea have a bidirectional relationship. Studies have shown that the prevalence of obstructive sleep apnea (OSA) is significantly higher in patients with epilepsy than in the general population. Untreated OSA may increase the risk of epileptic seizures through mechanisms such as hypoxia and sleep fragmentation.
Conversely, epileptic seizures themselves can affect sleep structure and exacerbate respiratory disturbances. This interaction creates a vicious cycle that requires comprehensive intervention.
Sleep apnea may be associated with the risk of epileptic seizures, but a direct causal relationship has not yet been confirmed. Studies have found that factors such as long-term hypoxia and sleep disorders may aggravate brain dysfunction and become a potential cause of epilepsy, especially in people who already have epilepsy or brain damage.
Can Sleep Apnea Cause Epilepsy ?
The prevalence of sleep apnea in the general population ranges from 2% to 4%. One study suggests that epileptic discharges may be the cause of sleep apnea in patients with epilepsy. There were no significant differences in weight or body mass index between patients with epilepsy and those without sleep apnea, ruling out obesity as a possible cause of sleep apnea.
The results of the study showed that there were no significant differences in sleep structure between patients with epilepsy and sleep apnea and those without sleep apnea, indicating that changes in sleep structure are not the primary cause of exacerbated seizures in patients with epilepsy and sleep apnea.
The results showed that patients with epilepsy and sleep apnea had low SaO2, indicating that apnea causes a decrease in SaO2. It is speculated that this pathophysiological change may be the primary cause of frequent seizures in patients with epilepsy and sleep apnea, and is likely one of the causes of “refractory epilepsy.”
Therefore, when conventional anti-epileptic treatment is ineffective, attention should be paid to whether the patient also suffers from sleep apnea.
Patients with epilepsy and sleep apnea who receive CPAP treatment while taking antiepileptic drugs have a significantly reduced frequency of epileptic seizures, indicating that sleep apnea treatment can improve sleep structure and hypoxemia, thereby reducing the frequency of epileptic seizures.
The Relationship Between Sleep Apnea And Epilepsy
Some studies have shown that the prevalence of sleep apnea in patients with epilepsy is higher than that in the general population, and these patients are more likely to develop refractory epilepsy (poor drug control).
The journal 《Sleep Medicine》 previously reported that treating sleep apnea (such as using a continuous positive airway pressure (CPAP) device) may reduce the frequency of epileptic seizures in some patients.
1. OSA is more common in patients with epilepsy
Approximately 30% of patients with epilepsy experience OSA (compared to approximately 3%-7% of the general population), particularly those with refractory epilepsy and nocturnal seizures. The prevalence of OSA in children with epilepsy can reach 20%, potentially related to craniofacial structural abnormalities or decreased muscle tone caused by antiepileptic medications.
2. OSA increases the risk of epileptic seizures
Repeated nocturnal hypoxia causes oxidative stress in brain tissue, lowering the seizure threshold. Reduced deep sleep also makes abnormal synchronization of brain electrical activity more likely. Studies have shown that the frequency of seizures in patients with moderate to severe OSA is 2-3 times higher than in those without OSA.
3. Possibility of bidirectional association
Certain types of epilepsy (such as nocturnal frontal lobe epilepsy) may cause airway obstruction due to muscle relaxation during an attack, thereby worsening snoring or apnea, forming a vicious cycle.
How Does Sleep Apnea Affect Epilepsy Symptoms ?
Respiratory arrest or abnormality during sleep may induce epilepsy, which is mainly related to abnormal discharge of brain cells caused by a lack of oxygen. It is common in patients with obstructive sleep apnea (OSA) and epilepsy.
1. Hypoxia triggers abnormal brain activity
Repeated apnea during sleep can lead to a decrease in blood oxygen saturation, and brain cells will suffer metabolic disorders due to a lack of oxygen, which may induce abnormal discharge of neurons and trigger epileptic seizures.
Studies have shown that approximately 10%-20% of patients with sleep apnea may have nocturnal epileptic seizures, especially those with refractory epilepsy who are at higher risk.
2. The superimposed impact of sleep structure disorders
Apnea interrupts sleep cycles, leading to reduced deep sleep and frequent arousals. Reduced sleep quality may lower the threshold for epileptic seizures and increase the risk of poor control of existing epilepsy.
How Do Seizures Affect Sleep Apnea ?
Epilepsy may trigger or worsen sleep apnea. This may be due to factors such as the epileptic seizure itself, the side effects of anti-epileptic medications, psychological factors, sleep-disordered breathing, and disruption of the body’s biological clock.
1. The seizure itself
During an epileptic seizure, abnormal neuronal discharges in the brain can cause symptoms such as convulsions and loss of consciousness. These symptoms can affect sleep quality and cause fatigue and drowsiness after the seizure.
Frequent epileptic seizures can also cause unusual behaviors such as awakenings and sleepwalking, further disrupting sleep. Some people with epilepsy may also suffer from obstructive sleep apnea, which causes symptoms such as breathing pauses and hypoxemia during sleep. These symptoms can affect sleep quality, causing frequent awakenings and leading to daytime drowsiness and fatigue.
2. Side effects of anti-epileptic drugs
Antiepileptic drugs are one of the mainstays of epilepsy treatment, but they can cause side effects such as drowsiness, dizziness, and fatigue. These side effects can affect sleep quality, leading to daytime sleepiness and difficulty falling asleep at night.
Some antiepileptic drugs can also affect sleep structure, causing shallow and unstable sleep. The negative impact of sleep apnea is often greater when patients take multiple antiepileptic drugs simultaneously.
3. Psychological factors
Epilepsy is a chronic disease. Patients need to face the troubles of the disease and the pressure of treatment for a long time. These factors may cause patients to have psychological problems such as anxiety and depression. These psychological problems will affect the patient’s sleep quality, making it difficult for patients to fall asleep at night or have symptoms such as dreaming and waking up easily during sleep.
Prevention And Intervention
1. Screening and diagnosis
Polysomnography (PSG) is recommended for all patients with epilepsy (especially those poorly controlled by medication); epilepsy should be excluded if patients with OSA have unexplained disturbances of consciousness.
2. Targeted intervention
Continuous positive airway pressure (CPAP)Â can reduce the frequency of epileptic seizures by 50%-60% and reduce the risk of accidental injuries caused by daytime sleepiness.
Medication adjustment: Benzodiazepines may aggravate OSA, and the anti-epileptic efficacy needs to be weighed against the risk of respiratory depression; drugs with less impact on breathing, such as lamotrigine, are preferred.
Positional therapy and weight loss: For patients with mild OSA and epilepsy, side sleeping and weight loss can provide dual benefits.
3. Multidisciplinary collaboration
The neurology and sleep medicine teams jointly developed a plan to regularly evaluate EEG and respiratory function, and to be vigilant about the effects of antiepileptic drugs on upper airway muscle tone.
