Sleep Characteristics of Children and Youth with Cerebral Palsy

Abstract

Background: Children with cerebral palsy are considered to be a population at risk for the occurrence of sleep difficulties. However, existing literature has been limited by subjective measures of sleep and has failed to examine contributing factors. Methods: Forty-five youth with cerebral palsy participated. Both youth and caregivers completed sleep-related questionnaires, while youth completed daily actigraphy for objective sleep assessments. Results: Sleep patterns, including sleep duration, wake after sleep onset, and sleep efficiency, are generally aligned with existing sleep recommendations. However, the number of awakenings was significantly higher in youth with cerebral palsy compared to these recommendations. Most youth experienced poor sleep quality, and approximately a quarter experienced insomnia. Being a boy and having a preexisting mental health diagnosis was associated with poor sleep quality and greater insomnia symptoms. Conclusions: Most youth with cerebral palsy experience a range of sleep difficulties. This study provides new information on sleep patterns in youth with cerebral palsy, highlighting the importance of addressing sleep issues in this population to improve their well-being and ultimately limit the negative impacts on overall health and quality of life.

Cerebral palsy is one of the most frequent causes of physical disability in children, affecting 1 to 3 per 1000. ¹ The primary difficulties associated with cerebral palsy include movement, muscle tone, and posture. ² Approximately 45% of youth with cerebral palsy report sleep problems compared to 25% of neurotypical youth.^3,4 Despite this prevalence, a need remains to comprehensively examine and characterize sleep patterns using a multitude of methods as well as to determine factors that may influence sleep outcomes in youth with cerebral palsy. Although sleep problems are considered an everyday experience in neurodevelopmental disabilities, they may be underreported and can go unrecognized. ³ Thus, the prevalence is likely underestimated, leading to inadequate management of sleep-related difficulties.^4,5 Individuals with cerebral palsy grapple with a unique set of sleep problems that can impact their well-being. The most commonly reported sleep disturbance is insomnia or persistent difficulties initiating or maintaining sleep. ⁴ People with cerebral palsy also experience excessive daytime sleepiness, which affects their ability to stay awake and, in turn, significantly impacts their daily functioning. ⁶ Furthermore, youth with cerebral palsy may experience more frequent wake bouts, overall poorer sleep efficiency (ie, time spent asleep compared with the time spent in bed), and greater sleep onset latency than neurotypical youth.^7,8

Inadequate sleep is concerning, considering the growing evidence that it can worsen daytime behavior, mood, and physical functioning in youth with and without cerebral palsy.^4,6 Soltani and colleagues ⁹ observed that insomnia is a significant risk factor for the first lifetime onset of anxiety, depression, and suicidality in neurotypical youth. Additionally, emerging evidence in youth with cerebral palsy demonstrates that sleep difficulties are associated with the onset of mental health issues, which may be the case in youth without cerebral palsy as well.

Contributors to Sleep Problems

The wide range of sleep problems experienced by youth with cerebral palsy stems from a combination of different factors. High rates of sleep problems in cerebral palsy may be due to physical discomfort and pain, ¹⁰ other medical/neurologic factors (ie, epilepsy, respiratory problems), and mental conditions.^5,10 Sleep problems can also present in various ways depending on the cerebral palsy subtype and the brain lesion's location.^5,10 For instance, youth with dyskinetic cerebral palsy, marked by involuntary movements, may have sleep disturbances because of these uncontrollable movements during the night.^5,10 Several demographic factors can also influence sleep in individuals with cerebral palsy, including age, gender, gross motor functioning, and cerebral palsy subtype.^4,11 For instance, frequent awakenings and early morning awakenings are common among children with more severe gross motor difficulties (Gross Motor Function Classification System) levels IV and V. ¹¹ Age also plays a significant role, with younger children generally having shorter sleep durations and poorer sleep quality.^4,12 In contrast, caregivers of older children with cerebral palsy report higher satisfaction with their child's sleep and indicate that their child wakes less frequently during the night than caregivers of younger children. ⁴ While sleep is vital for youth's well-being, existing sleep studies have only focused on one aspect of sleep (eg, sleep duration), primarily using caregiver-reported subjective measures to measure youth sleep and typically conceptualized sleep as an outcome rather than a predictor of health and well-being. ¹³ However, to ensure an adequate understanding of the complexities of sleep in youth, it is essential to consider multiple facets of sleep, such as duration, quality, and the associated factors. ¹⁴ To fill this gap, this study used a multimethod and informant approach to comprehensively characterize the sleep patterns of youth with cerebral palsy. This study has 3 aims: (1) describe multiple dimensions of sleep in a cohort of youth with cerebral palsy, (2) provide a detailed description of the biological (gender, age) and clinical (comorbidities, medication use) factors that are related to the sleep patterns, and (3) examine whether the presence of a mental health diagnosis is associated with insomnia severity.

Methods

Secondary Data Sources

This cross-sectional study involved secondary data analysis from a larger study examining associations between physiological factors and mental health in children and youth with cerebral palsy.

Participants and Procedure

Youth with cerebral palsy aged 8-17 years with any level of functional ability (as indicated by caregiver-reported Gross Motor Function Classification System level) were recruited with caregiver consent and/or child/youth assent by convenience sampling from a variety of local community agencies and relevant health care organizations. Consent was obtained from youth older than 14 years who were cognitively and socially or emotionally capable of consenting to participation. Capacity for consent was determined by considering the youth's intelligence and stage in development, their ability to reason about the risks and benefits regarding participation, as well as the consequences of not participating. Caregivers provided further insight into their child's functioning ability level, and previous psychological reports were also reviewed to determine capacity for consent. Youth and caregivers completed questionnaires administered online through Research Electronic Data Capture (REDCap), a secure online server. To participate, youth were required to have a diagnosis of cerebral palsy and read and write in English at least at a grade 2 level, as indicated by their previous psychological reports. Youth with other preexisting neurologic conditions, such as epilepsy not controlled by medication, traumatic brain injury or autoimmune disorders, were not eligible. After completing the questionnaires, youth were asked to wear an Actigraph for 1 week to capture objective sleep data. Participants received gift cards for their participation.

Measures

Demographics

Caregivers were asked to provide their child's age, motor functioning, race, family makeup, current medication usage, and annual household income. Additionally, they were asked to indicate if their child had any diagnoses related to mental health or neurodevelopmental conditions.

Actigraphy-Determined Sleep

Actigraphy (GT9X Link ActiGraph) was used to objectively assess sleep in the current study. Participants wore the actigraph on the nondominant wrist for 7 consecutive days. Wake periods in 60-second epochs were coded by the software (ActiLife). The Cole-Kripke sleep algorithm was applied to analyze the data with the Tudor-Locke “default” for sleep period detection, as these algorithms are valid and reliable in youth with cerebral palsy.^15,16 Four main sleep variables were measured: sleep duration (ie, total sleep time), wake after sleep onset (ie, wake time after initial sleep onset and before final morning awakening), number of awakenings (ie, the number of times an individual wakes up during the night), and sleep efficiency (ie, the proportion of time spent asleep over the total time spent in bed).

Sleep diary

Youth were asked to maintain sleep diaries daily for 7 consecutive days. Every evening (approximately 5:00 pm), caregivers and youth received secure links to REDCap. The daily diaries consisted of questions about their sleep the night before, including bedtime, wake time, and sleep quality (ie, “How would you rate your sleep last night?”).

Subjective sleep quality

Subjective sleep quality was assessed using the Sleep-Wake Scale. Youth between the ages of 13 and 18 years completed the Adolescent's Sleep-Wake Scale, ¹⁷ whereas caregivers of youth aged 8-12 years completed the Children's Sleep-Wake Scale. ¹⁷ Both scales include 5 sleep behavior subscales: Going to Bed, Falling Asleep, Maintaining Sleep, Reinitiating Sleep, and Return to Wakefulness. Each item is rated on a scale from 1 to 6 (eg, 1 = always to 6 = never), with higher scores indicating better sleep quality. The Sleep-Wake Scale provides a total sleep quality score, a composite measure considering all 5 sleep behaviors. Scores below 4 on the Adolescent's Sleep-Wake Scale or Children's Sleep-Wake Scale are associated with clinically significant sleep problems.^18,19 The Sleep-Wake Scale has demonstrated good validity and reliability in both neurotypical and neurodiverse youth.^17,18 Although not validated in individuals with cerebral palsy, the Sleep-Wake Scales have been successfully used in individuals with autism spectrum disorder. The current study found strong internal consistency for the Children's Sleep-Wake Scale and the Adolescent's Sleep-Wake Scale, with Cronbach's α values of .93 and .94, respectively.

Insomnia Severity Index

The Insomnia Severity Index ²⁰ consists of 7 items assessing the severity of sleep-onset and sleep maintenance difficulties, satisfaction with current sleep, daytime impairments, and degree of concern caused by sleeping problems (ie, How satisfied are you with your current sleep pattern?). Each item is rated on a scale from 0 (none) to 4 (very severe), with a maximum total score of 28. Scores of 15 or higher indicate clinically significant insomnia, whereas scores of 8 to 14 indicate subthreshold insomnia. For this study, a cut-off of 10 was used to detect insomnia symptoms, as recommended by Morin and colleagues. ²⁰ Although not validated in youth with cerebral palsy, the Insomnia Severity Index has been previously used to evaluate insomnia symptoms in youth with cerebral palsy. ¹¹ The ISI has been shown to have good internal consistency with a Cronbach's α of .82^20,21; in our study, the Insomnia Severity Index Cronbach's α was .91.

Data Analyses

Analyses were conducted using SPSS 26. Sleep patterns were compared to the sleep guidelines for neurotypical youth outlined by the National Sleep Foundation,^22,23 created and published by experts in the field. Table 1 displays the National Sleep Foundation's sleep parameter criteria used for comparison in the present study. For aim 1, sleep characteristics were averaged across the 7 days, except for the Insomnia Severity Index, which was collected only once before the weeklong data collection. Descriptive statistics were used to summarize each self-report and objective (ie, actigraphy and daily diaries) sleep-related variables. A series of bivariate correlations and independent t tests were used for normally distributed variables. There was minimal missing data, with less than 10% missing for all sleep variables apart from wake after sleep onset duration, number of awakenings, and sleep efficiency, which was missing for 9 participants. Sleep diary data was missing from 1 to 4 days, with the highest missing days on 1 and 7. Little's missing completely at random test resulted in a nonsignificant P value (χ²= 107.906, df = 115, P = .66), which demonstrated that data were missing in a random fashion. ²⁴

Table 1.

Sleep Parameters Recommended by the National Sleep Foundation (NSF). ^a

Sleep indicators	Definition	Norms for school-aged children	Norms for teens
Sleep duration b	Number of hours of sleep while in bed	9-11 h recommended; not recommended, <7 or >12 h	8-10 h recommended; not recommended, <7 or >11 h
Sleep efficiency	Ratio of total sleep time to time in bed	Sleep efficiency ≤74% does not indicate good sleep quality.
Number of awakenings	Number of episodes, per night, in which an individual is awake for greater than 5 min	Four or more awakenings per night are not an appropriate indicator for good sleep quality
Wake after sleep onset	Amount of time, in minutes, spent awake after sleep has been initiated and before final awakening	A WASO duration of ≥41 min does not indicate good sleep quality	A WASO duration of ≥51 min does not indicate good sleep quality.

Abbreviation: WASO, wake after sleep onset duration.

^a Definitions adapted from Ohayon and colleagues ²³

^b Sleep duration definitions adapted from Hirshkowitz and colleagues ²²

For aim 2, a 2-step hierarchical linear regression was conducted to investigate the association between a mental health diagnosis and insomnia severity symptoms. We defined the presence of a mental health diagnosis as a dichotomous variable, present or absent. Gender was also reported as a dichotomous variable. We first examined correlations in unadjusted models, followed by the regression model in which we adjusted for demographic covariates (age, gender, Gross Motor Function Classification System level).

Results

Sample Characteristics

Participants were 45 youth with an average age of 11 years (SD = 2.67; range, 8-17 years). Youth's caregivers reported Gross Motor Function Classification System levels ranged from 1 to 5, with 43% of youth having level 1 motor impairment, 38% level 2, 9% level 3, 7% level 4, and 2% level 5. Gross Motor Function Classification System level data were not obtained or available from 3 participants (sociodemographic data are presented in Table 2). Eighty-seven percent (n = 39) of youth were in a typical classroom placement with no additional support, 11.1% (n = 5) were in a special education classroom with additional support/or other accommodations, and 1 participant was homeschooled. More than half of the sample were boys (n = 26, 58%) and identified as White (n = 31). Approximately 24.4% (n = 11) of the youth had received a mental health diagnosis from a registered health professional prior to participation, that is, 3 youth had an anxiety disorder, 3 had attention-deficit hyperactivity disorder (ADHD), and 1 had depression. Five participants had multiple co-occurring diagnoses, with specific learning disorders, anxiety, and depression being the most common. Additionally, 35.6% (n = 16) of our sample reported taking medication; 9 participants were on psychotropic medication, 4 were on nonpsychotropic medication (eg, baclofen to treat muscle spasticity), and 3 did not provide any information regarding medication type.

Table 2.

Demographic Characteristics of Youth and their Caregivers (N = 45).

	Mean ± SD or n (%)
Youth
Age	11.5 ± 2.68
Gender
Girls	18 (40)
Boys	26 (57.8)
Other	1 (2.2)
GMFCS a
Level I	18 (42.9)
Level II	16 (38.1)
Level III	4 (8.9)
Level IV	3 (6.7)
Level V	1 (2.2)
Mental health diagnosis
Yes	11 (24.4)
No	34 (75.5)
Age	43.8 ± 6.80
Relationship with child
Biological parent	39 (86.7)
Adoptive parent	4 (8.9)
Other	2 (4)
Education
Some high school/high school graduate	2 (4.4)
Some college/or technical school	18 (40)
College degree/graduate degree	25 (55.6)
Annual household income, CanD
<40 000	1 (2.2)
40 000-79 999	13 (28.9)
≥80 000	22 (48.9)
Prefer not to say	9 (20)

Abbreviation: CanD, Canadian dollars; GMFCS, Gross Motor Function Classification System.

^a GMFCS level was missing or not available for 3 participants.

Objective Sleep Characteristics

The sleep characteristics of youth were determined using actigraphy. See Table 3 for a description of youth's sleep characteristics.

Table 3.

Distribution of Youth Sleep Patterns based on Gender Differences. ^a

	Full sample, Mean ± SD (n = 42)	Females, Mean ± SD (n = 13)	Males, Mean ± SD (n = 28)
Sleep data b
Sleep duration (h)	10:01 ± 0:59	9:49 ± 1:17	10:09 ± 0:44
Bedtime (h)	21:35 ± 1:18	21:54 ± 1:30	21:22 ± 1:10
Wake-up time (h)	7:21 ± 1:04	7:35 ± 1:13	7:13 ± 0:59
Wake after sleep onset (min)	36.0 ± 15.1	32 ± 12.5	35 ± 14.0
Number of awakenings	14.0 ± 5.3	12.5 ± 5.0	14.0 ± 4.3
Sleep efficiency (%)	90.0 ± 4.8	90.0 ± 5.0	90.0 ± 4.8

^aThe discrepancy in sample size reported in the table is due to missing or incomplete data.

^b Derived from actigraphy.

Bedtime and Wake-Up Time

On average, youth reported a bedtime of 9:35 pm (SD = 1:18) and a wake-up time of 7:21 am (SD = 1:04). Youth's bedtime ranged from 6:42 pm to 1:44 am, whereas wake up time ranged from 5:00 am to 10:30 am. Although most youth had early bedtimes, 5 youth in our sample had average bedtimes past 10:30 pm. Significant differences were not observed in bedtime and wake-up time patterns based on gender, age, mental health diagnosis, caregiver education, household income, and medication status; all P values > .05. However, we found significant differences among youth with different levels of gross motor functioning (I-II versus III-V). Youth with gross motor functioning levels I-II had significantly later bedtimes (mean = 9:48 pm, SD = 1:18) and wake-up times (mean = 7:35 am, SD = 1:00) compared to youth with levels III-V (mean = 8:27 pm, SD = 0:58, and mean = 6:34 am, SD = 0:47, respectively) (t₍₃₆₎= 2.56, P = .015, Cohen d = 1.07, and t₍₃₆₎= 2.50, P = .017, Cohen d = 1.04, respectively).

Sleep Duration

The average sleep duration of youth was 10:01 hours per night (SD = 0:59), ranging from 7.5 to 12.85 hours. Only 2 youth slept more than the recommended amount for their age based on the National Sleep Foundation recommendations. No other differences were observed based on gender, mental health diagnosis, caregiver education, household income, or medication status (all p's > .05).

Number of Awakenings

Youth experienced a mean NAO of 14 awakenings per night (SD = 5.3), with the number of awakenings ranging from 1 to 29 awakenings. According to the National Sleep Foundation, nighttime awakenings exceeded the 4 awakenings typical for youth to indicate good sleep quality. There were no differences in number of awakenings by age, gender, mental health diagnosis, Gross Motor Function Classification System level, caregiver education, household income, or medication status (all P's > .05).

Wake After Sleep Onset

The average duration of time that youth were awake after initially falling asleep (ie, wake after sleep onset) was quite variable. The mean wake after sleep onset duration was 36 minutes (SD = 15 minutes), ranging from 8 to 76 minutes. Eight youth experienced wake after sleep onset durations that exceeded the recommended amount for their age groups by the National Sleep Foundation. ²² Among school-aged children (6-13 years), 6 participants had wake after sleep onset duration greater than 41 minutes (mean = 52.17, range 46.89-65.44), and 2 adolescents (14-17 years of age) had wake after sleep onset durations exceeding 51 minutes (M = 68.59 minutes, range 60.50-76.67), indicating a potential concern for disrupted sleep. Youth who were taking medication had significantly lower wake after sleep onset (mean = 28.7 minutes, SD = 8.93) compared with youth not taking medication (mean = 40.5, SD = 16.12; t₍₃₂₎= −2.73, P = .019, Cohen d = 0.86). There were no differences in wake after sleep onset by age, gender, mental health diagnosis, Gross Motor Function Classification System level, caregiver education, or household income (all P's > .05).

Sleep Efficiency

On average, sleep efficiency was within the guidelines of the National Sleep Foundation, which recommends sleep efficiency above 85%. The mean sleep efficiency was 89.9% (SD = 4.7%), ranging from 79.9% to 97.3%, indicating that most youth participants did not have poor objective sleep quality. However, 6 youth's sleep efficiency (13.3%) fell below the range for “good sleep quality” (<85%) but remained above the range for “poor sleep quality” (>74%), ranging from 79.9% to 82%. There were no differences in sleep efficiency by age, gender, mental health diagnosis, Gross Motor Function Classification System level, medication status, caregiver education, or household income (all P's > .05).

Subjective Ratings of Sleep Quality

Given the range of ages of youth and consistent with existing literature, total scores from the Children's Sleep-Wake Scale and Adolescent's Sleep-Wake Scale were analyzed together as an overall representation of sleep quality in the current sample. The mean score for Children's Sleep-Wake Scale was 4.03 (SD = 1.07, range = 1.72-5.80), and for the Adolescent's Sleep-Wake Scale, it was 3.12 (SD = 1.31, range = 1.04-5.20). The overall total sleep quality score for all youth was 3.68 (SD = 1.2, range = 1.04-5.80), indicating that most youth experienced low sleep quality.^18,19 Lastly, we found significant differences between boys and girls in terms of sleep quality (see Table 4). Girls had a better overall sleep quality compared to boys, t₍₄₀₎= −2.11, P = .041, Cohen d = 0.66. No other differences in subjective sleep quality by age, mental health diagnosis, Gross Motor Function Classification System level, medication status, caregiver education, or household income were observed (all P's > .05).

Table 4.

Distribution of Youth Subjective Sleep Quality Based on Gender Differences.

	Full sample, Mean ± SD (n = 42)	Females, Mean ± SD (n = 18)	Males, Mean ± SD (n = 24)	t
Total sleep quality score a	3.68 (1.24)	4.15 (1.09)	3.37 (1.26)	−2.11*
Going to bed a	3.19 (1.33)	3.27 (1.37)	3.13 (1.36)	−0.358
Falling asleep a	3.93 (1.35	4.28 (1.08)	3.75 (1.48)	−1.28
Maintaining sleep a	3.48 (1.48)	3.74 (1.48)	3.40 (1.44)	−0.737
Reinitiating sleep a	3.44 (1.60)	3.48 (1.60)	3.47 (1.60)	−0.005
Returning to wakefulness a	3.69 (1.55)	3.86 (1.30)	3.58 (1.30)	−0.571

^a Ratings are calculated as a mean score for each subscale, ranging from 1 to 6, with higher scores indicating better sleep quality. Measures include both the Children's Sleep-Wake Scale (CSWS) and the Adolescent's Sleep-Wake Scale (ASWS).

The discrepancy in numbers reported in the table is due to missing or incomplete data.

*Significant group difference (P < .05)

Sleep Problems: Insomnia

The Insomnia Severity Index score among all youth participants was 6.76 (SD = 6.59, range = 1-27), indicating that most youth were not presenting with clinical insomnia; however, approximately 11% had moderate-to-severe insomnia symptoms (n = 5, 10.9%). Nine youth reported subthreshold insomnia (Insomnia Severity Index total score 8-14), 2 had scores indicating clinically moderate severity insomnia (Insomnia Severity Index total score range = 15-21), and 3 had scores indicating clinically severe insomnia (Insomnia Severity Index total score range = 22-28). Furthermore, primary sleep complaints among youth included difficulties with sleep initiation (38.1%), early morning awakenings (30.9%), sleep maintenance (28.6%), and daytime impairment (28.6%). There were no significant differences in Insomnia Severity Index total scores by age, gender, mental health diagnosis, Gross Motor Function Classification System level, medication, caregiver education, or household income (all P > .05).

Hierarchical Regression Analyses

The results of the regression analyses are presented in Table 5. After adjusting for covariates (ie, gender, Gross Motor Function Classification System level, and age), mental health diagnosis was significantly positively associated with insomnia severity (Insomnia Severity Index total score), indicating that mental health diagnosis had a significant incremental effect on insomnia severity over and above control variables. Block 1 (demographic variables only) explained 9.7% of the variance in the model (P = .305). Block 2 of the hierarchical linear regression, which included mental health diagnosis while controlling for participant covariates, accounted for a significant amount of unique variance in insomnia severity, R²= .26, ΔR²_{(1, 34)}= .16, P = .010.

Table 5.

Regression Predicting Insomnia Severity From Mental health Diagnosis.^a

						95% CI for B
Regression step	B	SE	β b	t	P	Lower	Upper
Block 1
Age	−0.52	2.24	−0.20	−1.21	.29	−1.39	0.35
Gender	−2.36	0.43	−0.77	−1.07	.23	−6.93	2.16
GMFCS level	1.24	0.25	0.17	0.998	.33	−1.23	3.78
Block 2
Age	−1.25*	0.10	−0.50	−0.53	.01	−2.23	−0.90
Gender	−1.21	0.48	−0.09	−0.50	.55	−5.50	3.02
GMFCS level	0.84	1.22	0.01	0.07	.95	−2.40	2.56
MH diagnosis	8.41*	3.10	0.54	2.72	.01	2.10	14.70

Abbreviations: GMFCS, Gross Motor Function Classification System; SE, sleep efficiency.

^a For gender, 1 = boys, 2 = girls. For mental health diagnosis, 1 = yes diagnosis, 0 = no diagnosis.

^b Standardized β.

*P < 0.05.

Discussion

This study provides objective, self-reported, and multidimensional evidence of sleep difficulties in youth with cerebral palsy. By exploring the influence of youth demographics on sleep, this study sheds light on the intricate interplay between these factors and sleep outcomes. Importantly, these findings may serve as a foundation for targeted interventions and personalized approaches to supporting youth with sleep difficulties.

Youth in our study had significantly greater sleep disruptions than previously reported, as determined by actigraphy. ⁶ Specifically, youth showed varying levels of wake after sleep onset duration, with approximately a quarter experiencing wake after sleep onset durations exceeding the recommended amount. This demonstrates that wake after sleep onset durations could be a distinct characteristic of sleep in this group, perhaps because of pain-induced disruptions. ⁶ Although the majority of our sample had wake after sleep onset durations within National Sleep Foundation age-appropriate guidelines, they did experience a significantly higher number of awakenings per night (ie, an average of 14 awakenings), surpassing the National Sleep Foundation's age-appropriate guidelines of fewer than 4 awakenings per night.

Although sleep efficiency was within the recommended amount, as assessed through actigraphy, most participants reported poor subjective sleep quality. Additionally, girls had better overall sleep quality compared with boys. Although sleep difficulties are common and prevalent in youth with cerebral palsy, no specific association with gender or sex has been reported in the literature. ³ Thus, our findings suggest a potential gender difference in subjective sleep quality that warrants further investigation. Other actigraphic sleep parameters, including sleep duration, bedtime, and wake-up time, were consistent with what we would expect of same-age peers.^22,25 It is important to highlight that most of our sample did not meet the cut-off for clinical insomnia; however, a small subset of youth had moderate-to-severe insomnia symptoms.^20,21 Future research should examine factors that may contribute to clinically significant insomnia symptoms in youth with cerebral palsy.

The mean sleep duration in our study aligns with the National Sleep Foundation's age-appropriate guidelines and is in line with previous research. ⁴ In contrast, using actigraphy, Hulst et al ⁶ found that only 35.5% of their sample of youth with cerebral palsy met age-appropriate recommendations. Inconsistencies between the present findings and previous literature could be due to the potential impact of the COVID-19 pandemic, as most of the present data were collected during the early phases of the pandemic. Indeed, the pandemic led to significant lifestyle changes in youth without cerebral palsy, impacting sleep timing behaviors,^26–28 and could have resulted in individuals either sleeping less or exceeding the National Sleep Foundation's guidelines for sleep duration. ²⁸ Given that no study has examined the impact of the pandemic on the sleep patterns of youth with cerebral palsy, it is unclear if the current findings represent our sample's “normal” sleep durations or if the pandemic might have impacted the sleep in our study sample.

Our findings did not reveal significant differences in sleep habits and sleep/wake parameters based on youth demographics. Although most youth in our sample had early bedtimes, 5 had average bedtimes past 10:30 pm. Although bedtime guidelines for youth with cerebral palsy do not exist, the limited existing literature suggests that bedtimes beyond 10:30 pm may be associated with higher odds of experiencing mental health outcomes, such as greater anxiety and increased negative thoughts.^25,29 More research is needed to determine if a later circadian profile is the norm for this population as it is in individuals with other NDDs, such as ADHD. ³⁰

Here, we found that almost all but 1 participant had 4 or more awakenings per night, which indicates poor sleep quality. ²³ These awakenings could be linked to secondary problems youth experience, such as pain, spasticity, and muscle tension.^4,31,32 Further research is needed to determine what underlying mechanisms may contribute to these increased awakenings.

Regarding objective sleep quality, most youth displayed average sleep efficiency based on actigraphy, ²³ consistent with Hulst et al ³³ reporting an sleep efficiency of 82.4%, confirming normal sleep patterns. These authors found that approximately half of the children had an average sleep efficiency above 85%, like most youth in our sample (64.4%). ³³ Here, we also found that objective sleep quality was inconsistent with youth- and caregiver-reported subjective sleep quality. The average sleep quality was reported as mean = 3.67, which is lower than what has been reported in the literature for both neurodiverse and neurotypical youth. ³⁴

In our analysis, we also considered the potential impact of sociodemographic factors such as caregiver's education and annual household income on sleep outcomes. However, we did not observe any significant differences in sleep variables based on these socioeconomic factors. This suggests that within our particular sample, factors such as caregiver's education and household income do not appear to significantly influence sleep patterns or quality. These findings were unexpected, as Zhang and colleagues found that neurotypical youth from lower-income families and those with caregivers with lower educational levels tended to have shorter sleep durations. ³⁵ However, other factors may contribute to our nonsignificant findings. For instance, many youth in our present sample were from higher socioeconomic backgrounds, which may have reduced the impact of these socioeconomic factors on sleep in our participants.

The prevalence of insomnia in the present study was relatively low, with only 11.1% experiencing moderate to severe insomnia. Löwing and her colleagues ¹¹ found that young adults with cerebral palsy reported a median Insomnia Severity Index score of 3, suggesting that most youth in their study had lower insomnia symptom levels. Moreover, Löwing and colleagues ¹¹ reported significant differences in median Insomnia Severity Index total scores based on Gross Motor Function Classification System levels, indicating greater insomnia severity with higher motor difficulties (ie, Gross Motor Function Classification System level V). Unlike other studies, no differences in insomnia severity total were found between ambulatory and nonambulatory Gross Motor Function Classification System levels. Poor sleep quality, both objective and subjective, is a characteristic feature of insomnia.^36,37

Although the present study identified poor subjective, but not objective, sleep quality, it is essential to note that the frequent use of both psychotropic and nonpsychotropic medications may mask sleep disorders such as insomnia.^38–40 More than one-third of the youth in our sample were taking medications, with most on psychotropic medication, which can contribute to subjectively feeling satisfied with sleep despite “good” objective sleep quality.^39,40 Although we found no significant difference in Insomnia Severity Index, subjective sleep quality, or sleep efficiency between youth using prescription medication and those not using any prescription medications, with a larger sample size, it is possible that we might see significant differences between these important sleep variables. This aligns with Hulst and colleagues’ findings, ⁶ who also reported no differences in subjective sleep patterns based on medication status in their study of youth with cerebral palsy. Youth with cerebral palsy may report poor subjective sleep quality because of various factors. First, undiagnosed sleep disorders that affect sleep quality are common in neurodiverse individuals, even when objective sleep measures, such as sleep efficiency and wake after sleep onset duration, appear relatively normal. ⁴¹ Many children and youth with underlying sleep problems go undiagnosed and untreated for conditions like insomnia, sleep apnea, or restless leg syndrome.

Furthermore, we found a significant association between the presence of a mental health diagnosis and the severity of insomnia symptoms. This finding aligns with existing literature in neurotypical youth, where insomnia severity is linked to an increased likelihood of first-lifetime onsets of mood and anxiety disorders. ⁹ Given the interplay between insomnia and other mental health conditions, future studies need to explore how symptoms of depression and anxiety impact the severity of insomnia in youth with cerebral palsy. Mental health concerns like depression and anxiety are not only common in individuals with cerebral palsy but also exacerbate sleep problems, creating a vicious cycle that impacts overall functioning and quality of life. ⁴² The bidirectional relationship between sleep and mental health means that poor sleep can lead to worsening mental health symptoms and vice versa. This highlights the importance of an integrated treatment approach that combines both sleep difficulties and mental health. Interventions could include pharmacologic treatments, behavioral therapies, and mental health supports tailored to the needs of youth with cerebral palsy and their families.

Strengths and Limitations

Strengths of our study include the comprehensive characterization of sleep patterns, disturbances, and factors associated with sleep among youth with cerebral palsy, using both subjective and objective measures. Additionally, our study directly linked reported sleep dimensions to the National Sleep Foundation sleep guidelines. Although these guidelines are not specifically intended for youth with cerebral palsy, this approach allowed us to contextualize the sleep patterns of this population within the established standards and benchmarks set by the National Sleep Foundation, providing valuable insights into sleep patterns and dynamics during this critical developmental period.

The findings of the study should be interpreted in light of several limitations. These include the small sample size, the cross-sectional nature of the data, and the operationalization of mental health diagnoses solely as a unidimensional construct. Additionally, the sample primarily consisted of participants who identified as White and from high socioeconomic backgrounds. Furthermore, our assessment of sleep quality may have limitations because of our utilization of the Children's Sleep-Wake Scale, which relies on parent-reported sleep quality for younger participants, and that both the Children's Sleep-Wake Scale and the Adolescent's Sleep-Wake Scale have not been validated in individuals with cerebral palsy. This methodology could lead to underreporting of actual sleep quality; however, this ensures consistency with the validation and development of the measures. Although a strength of the present study was taking a comprehensive approach in understanding the sleep of children and youth with cerebral palsy, sleep onset latency (or the duration from bedtime to sleep onset) is another important indicator sleep that was not examined in the present study. Future research examining sleep characteristics in neurotypical and neurodiverse youth should incorporate this to ensure a comprehensive examination of sleep outcomes. Lastly, it is worth noting that the gold standard for the assessment of sleep is the use of polysomnography. However, sleep assessment based on actigraphy measurements has been shown to be valid and reliable in youth with cerebral palsy.^7,8

Conclusion

This study shows that youth with cerebral palsy generally have average sleep duration, sleep efficiency, and wake after sleep onset duration in relation to the National Sleep Foundation's sleep guidelines. However, they are vulnerable to fragmented nighttime sleep and experience poor sleep quality. Furthermore, co-occurring diagnoses may contribute to greater insomnia severity, compromising overall functioning. This study plays a crucial role in developing our understanding of sleep characteristics among youth with cerebral palsy and contributes to the very limited literature in this vulnerable group. Findings from this study have implications for promoting sleep health in youth with cerebral palsy, highlighting the need for early screening and treatment to address these difficulties effectively. Further research examining daily assessments of sleep, mood, anxiety, and pain using a microlongitudinal approach is needed. Early identification and sleep health promotion can mitigate long-term sleep problems, which is essential for youth with cerebral palsy, who are already a vulnerable population.