Primary steps for primary care: Sleep disorders in epilepsy and cerebral palsy
Sleep disorders are common among the general pediatric population, but children with neurologic conditions are more likely to develop certain sleep disorders. Two of the most common pediatric neurologic conditions—epilepsy and cerebral palsy—and their frequently associated sleep disorders are presented here. Recognizing the elements that contribute to sleep disturbances in these unique populations can guide initial evaluation and management. Restoring sleep may not only improve quality of life, but also may improve the outcomes of the neurologic condition.
What are the initial steps in evaluation?
Evaluation should start with a detailed history and physical exam. A dedicated sleep history should include information such as sleep environment, bedtime routine, sleep and wake times, nap patterns, and overnight behaviors such as snoring, abnormal movements, sleepwalking and awakenings. A thorough physical exam is warranted, as it may expose risk factors for sleep-disordered breathing such as craniofacial abnormalities, obesity, axial tone abnormalities and enlarged tonsils.
Inappropriate sleep associations (like falling asleep while watching TV, inconsistent bedtime routine, excessive caffeine intake, late afternoon naps and other signs of poor sleep hygiene) are pervasive among children and adolescents suffering from sleep problems, regardless of whether they have a chronic neurologic condition. It is always recommended to review good sleep hygiene with patients and families.
The impact of epilepsy on sleep is multi-factorial and likely related to a combination of the direct effects of the seizures, side effects from anti-seizure medications and psychosocial consequences. The relationship between epilepsy and sleep disorders is complex and bi-directional. Having epilepsy can cause sleep disturbance and poor sleep, while sleep deprivation can worsen seizure frequency.
Sleep studies in children with epilepsy show increased arousals and sleep fragmentation.1,2 This fragmented sleep can result in impaired daytime functioning with drowsiness, decreased attention, behavioral changes and mood disturbance. Sleep fragmentation is worse in children who have nocturnal seizures. Compliance with anti-seizure medications may decrease nocturnal seizure frequency and improve sleep fragmentation.1-3 Nevertheless, many anti-seizure medications also affect sleep and may induce drowsiness (e.g., valproic acid) and sometimes insomnia (e.g., lamotrigine).3 Concern for new or worsening nocturnal seizures or anti-seizure medication-induced sleep disturbance should be brought to the attention of the child's neurologist. Sleep deprivation is a common trigger for seizures; therefore, patients and families should be counseled to adhere to a bedtime that allows for age-appropriate adequate hours of sleep.
It is important not to overlook the unique challenges children with epilepsy may face as it relates to sleep. Resistance to bedtime and/or inability to fall asleep should trigger further inquiry. In some children, sleep-onset insomnia may be a manifestation of their fear of nocturnal seizures and/or fear of SUDEP (sudden unexpected death in epilepsy). In these instances, psychological counseling to address the sleep anxiety may be more helpful than sedating medications in the long term. Parents of children with epilepsy may choose to bed-share or room-share to monitor the child. There is evidence that the presence of another individual at least 10 years of age and of normal intelligence is associated with a decreased SUDEP risk.4 However, the abrupt change to the child's sleep environment may prevent the child from obtaining adequate or restful sleep. Common disruptions include parents that snore, parents who go to bed late, parents whose hypervigilant actions wake the child overnight, or the child's new sleep space is uncomfortable. Addressing the disruptive factors is key. Conversations about balancing seizure safety and optimizing the sleep environment should be revisited at different times. Perspectives and priorities can shift depending on the current level of seizure control and as more time since the diagnosis passes.
Compared to the general pediatric population, children and adolescents with epilepsy have higher rates of depression and anxiety, both of which contribute to insomnia. A University of California, Los Angeles study found a 33% incidence of affective and anxiety disorders and 20% incidence of suicidal ideation in the 171 pediatric epilepsy patients studied. 5 Only one-third of the children had received some form of mental health service.5 Early detection and treatment of comorbid mood disorders can improve sleep. Talk therapy is efficacious and Selective serotonin reuptake inhibitor (SSRIs) are the preferred first-line medications. Referral to a psychologist who specializes in cognitive behavioral therapy for insomnia (CBT-i) is useful in treating sleep anxiety and negative sleep associations.
The prevalence of obstructive sleep apnea (OSA) in children with epilepsy is higher than the general pediatric population, estimated between 30% and 60%.6 The risk is highest in medically refractory patients and the obstructive index increases with increasing number of anti-seizure medications.6,7 Therefore, children with uncontrolled seizures on multiple anti-seizure medications and complaints of sleep disturbance should be screened for OSA and referred for a sleep study if clinical suspicion is high.Treatment of OSA has been shown to improve seizure control.8,9
Cerebral palsy (CP) refers to disorders of posture, tone and movement due to injury to the brain prior to or shortly after birth. Children with cerebral palsy often have comorbid epilepsy, neurodevelopmental disorders, like autism and ADHD, and varying degrees of intellectual disability. Given such, these children display a wide range of sleep disturbances.
Structural brain lesions can disrupt sleep/wake cycle generating pathways causing profound circadian rhythm disturbances such as irregular sleep wake disorder (ISWD), which is characterized by short periods of sleep (2-3 hours) throughout the day and night without any discernable pattern. Bright light exposure along with physically and socially engaging activities during the day and avoidance of bright light and vigorous activity in the evening may help consolidate nighttime sleep.10 Children that have alterations in light perception may develop a non-24 sleep wake circadian rhythm disorder marked by normal sleep length with ever-shifting sleep onset time due to lack of day/night entrainment. Techniques similar to those used in ISWD can be attempted, but sleep rarely reaches normalcy in these patients.11 Pharmacologic treatments are limited for patients with circadian rhythm disorders and medication use should be directed by a sleep medicine physician.
Brain lesions increase the risk of central sleep apnea, while tone abnormalities affecting the airway contribute to obstructive sleep apnea. All children with cerebral palsy should undergo screening for sleep-disordered breathing. If clinical suspicion is high, the child should be referred for a sleep study.
Children with CP have varying degrees of spasticity, dystonia, scoliosis, contractures and other abnormalities that can be associated with physical pain and discomfort. Pain was shown to have the strongest negative impact on sleep in a Canadian study of children with physical disabilities.12 Treating severe spasticity with Botox® injections and baclofen via intrathecal pump has been shown to decrease nighttime awakenings.13,14 Strategic use of oral baclofen and PT/OT along with positioning pillows and overnight turning can often provide relief for mild-moderate pain that interferes with sleep. Severely affected children should be referred to a neurologist or physical medicine and rehabilitation physician who can evaluate and offer advanced treatments like Botox®.
Children with CP who have dysphagia, restrictive eating habits, or otherwise limited diets may be at risk for iron deficiency anemia. Iron deficiency has a clear link with restless leg syndrome (RLS) in children.15 Symptoms of RLS are often difficult to communicate for any child, but especially for children who may have associated intellectual disability. When spasticity or contractures are present, complaints of leg discomfort may mistakenly be attributed to musculoskeletal pain. A ferritin level below 50 ng/mL in a child with CP and leg complaints and/or restless sleep warrants a trial of iron supplementation (3-6 mg elemental iron/kg/day for 3 months).
When does the patient need to see a sleep medicine physician?
Any sleep disorder that fails to improve with initial intervention or is rapidly worsening should be referred to a sleep medicine physician. Referring patients for evaluation of sleep disorders that will require confirmatory diagnostic testing or ongoing monitoring and management, such as OSA, chronic insomnia, narcolepsy and circadian rhythm disorders, is appropriate. It is also recommended to refer patients that have a high risk for sleep-disordered breathing due to special conditions such as neuromuscular disease (e.g., Duchenne muscular dystrophy), trisomy 21 (Down syndrome) and achondroplasia.