When autism is found alongside (or co-morbid with) another disorder, diagnosis and treatment may be complicated. One example is cerebral palsy and autism spectrum disorder, where severity and symptoms tend to present differently in each individual.
Autism rates among children with cerebral palsy are elevated when compared to prevalence in the general population. Even doctors admit the dual diagnosis of cerebral palsy and autism spectrum disorder presents challenges, so it’s little wonder that parents have questions when symptoms of both conditions are present in their child.
Observance of possible co-occurring conditions
Many studies (Bjorgaas et al., 2014) mention the importance of paying attention to autism symptoms in children with cerebral palsy. Timely diagnosis of autism in a child with cerebral palsy may lead to early intervention which could positively influence the child’s developmental trajectory and social functioning.
Cerebral palsy and autism are often diagnosed around the same age in young children. Unfortunately, the fact that these separate conditions share symptoms makes misdiagnosis a possibility. Some feel wide media coverage of autism may skew doctors’ diagnosis, while others feel more sinister reasons like liability in a medical malpractice claim could lead to a medical professional diagnosing autism rather than cerebral palsy.
In this article, I will examine the incidence and prevalence of cerebral palsy and autism co-occurring in children. I will also look at some of the issues complicating diagnosis and therapy, since standard testing for autism may not be appropriate for children with muscle control and motor function impairments.
Comorbidity of autism spectrum disorder and cerebral palsy in children
Findings from a study (Christensen et al., 2014) suggest 6.9% of children with cerebral palsy have co-occurring autism. The rate of prevalence of autism in the general population is therefore lower at 1.9% according to CDC’s Data and Statistics on Autism Spectrum Disorder.
A systematic review (Craig et al., 2019) investigated the prevalence of comorbidity between cerebral palsy, autism spectrum disorders and attention deficit hyperactivity disorder (ADHD). The review confirmed that ADHD and autism occur more commonly in individuals with cerebral palsy compared to the general population.
Overlapping symptoms
While autism and cerebral palsy are completely separate disorders with different characteristics, there are symptoms that overlap, these include:
- Delayed first word, language impairment and/or speaking difficulties
- Awkward, abnormal or repetitive movements
- Walking in an atypical manner
- Sensory symptoms (sensory processing disorders are common in autistic children and children with cerebral palsy)
When diagnosing co-occurring autism in a child with cerebral palsy, specialists may need to discern between behaviors and symptoms due to cerebral palsy and autism: for example writhing and jerking movements due to lack of muscle control or impaired motor functioning (which may be symptoms of a subtype of cerebral palsy) versus repetitive, restricted movements characteristic of autism spectrum disorder.
Similarly, communication deficits also need to be assessed with care: autism affects social communication and interaction, while cerebral palsy may affect the muscles involved in speaking. Furthermore, both conditions may be comorbid with intellectual disability and sensory difficulties which could also affect speech and language.
Difficulties with dual diagnosis of ASD and cerebral palsy
The study mentioned above (Craig et al., 2019) found the gold standard of methodologies for diagnosing autism and ADHD were not suitable for children with motor problems. The researchers concluded that future psychometric studies are needed to promote the development of measures suitable for those with cerebral palsy.
Parent-completed questionnaires are commonly used to screen for autism, but sometimes questions relating to behavior may not be appropriate for a child with motor function impairment. Play-based assessments may involve the handling of toys, which is also not a testing method appropriate for many types of cerebral palsy.
An accurate diagnosis may therefore depend on specialists who are familiar with both conditions, those who are aware of the intricacies of autism presentation when motor functioning may be compromised. When examining the main characteristics and common symptoms of cerebral palsy and autism, differences and similarities become apparent.
What is autism spectrum disorder (ASD)?
Autism is being diagnosed at an increasingly early age by doctors and pediatricians. When parents notice symptoms like repetitive/restricted behavior, social withdrawal, lack of eye contact, and late talking they may become worried about autism and request a medical consultation.
The Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM–5; American Psychiatric Association, 2013) is often used by doctors for the classification and diagnosis of cognitive conditions. The latest edition of the manual consolidated previous categories like asperger’s syndrome, pervasive developmental disorder and others into the umbrella term: autism spectrum disorder (ASD).
The DSM-5 criteria for an autism diagnosis are arranged in two core areas of deficits:
- Persistent difficulties with social-communication or social interaction
- Restricted, repetitive and/or sensory interests or behaviors
The DSM-5 lists all symptoms, and the number of these which need to be present for an autism diagnosis. Symptoms should cause significant difficulty in important areas of the child’s life, and such symptoms should be present from early on in the child’s life—even if manifestation only occurs at a later stage (American Psychiatric Association, 2013). For examples of these symptoms, and comprehensive diagnostic criteria, the DSM-5 should be consulted. A child will only be diagnosed with autism if symptoms are not better explained by another condition.
A child diagnosed with cerebral palsy may also lack social skills, or they may have difficulty with social interactions and communication—this may be due to symptoms associated with the disorder, particularly as children with cerebral palsy often have trouble controlling the muscles in their face and throat. Alternatively, the child may have a dual diagnosis of autism and cerebral palsy that accounts for social skills deficits or communication deficits.
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What is cerebral palsy?
Cerebral palsy is an umbrella term which includes many diverse symptoms mainly based on motor function and posture impairment that occurs in early childhood. A definition of cerebral palsy, developed by an international group of experts (Christine et al., 2007) was summarized as follows: “Cerebral palsy is a group of permanent, but not unchanging, disorders of movement and/or posture and of motor function, which are due to a non-progressive interference, lesion, or abnormality of the developing/immature brain.”
There are five main types of cerebral palsy:
- Spastic (the most common type)
- Ataxic
- Hypotonic
- Athetoid
- Mixed
A pervasive myth tells us that cerebral palsy is caused only by a lack of oxygen at birth or by a serious injury at birth. A small percentage of cases may be attributed to complications at birth, but for many other children with cerebral palsy the cause is unknown.
Risk factors have been identified and include: a serious maternal infection during pregnancy, maternal medicine used during pregnancy, maternal thyroid disorder during pregnancy, premature birth, low birthweight, congenital disorders, and other related factors.
As mentioned above, cerebral palsy presents differently in each individual, and differs according to type (of cerebral palsy) and severity. Common symptoms include:
- In babies, low muscle tone and poor muscle control could present in difficulty holding up the head, unusual posture, and the child may struggle with swallowing or feeding
- In toddlers, developmental milestones like walking and talking may not be reached due to slow or impaired motor development
Cerebral palsy is not a disease, rather the term refers to a combination of symptoms. There is a wide spectrum of severity; some children may be able to get around or stand with the assistance of a brace or walker, while others are not able to walk. Communication and learning abilities also vary in children with cerebral palsy. Determining whether communication deficits and repetitive behaviors are due to cerebral palsy or a comorbid condition like autism is a challenge that requires better, more appropriate testing.
As with autism, symptoms of cerebral palsy can vary quite significantly. An article (Shevell, 2018) makes a convincing case for replacement of the term cerebral palsy with cerebral palsy spectrum disorder. The author feels the heterogeneous nature of cerebral palsy is self-evident; mention is made of the analogous case of autism—a condition with a name that transitioned to include the word “spectrum”.
Identifying autism in a child with cerebral palsy
With overlapping symptoms and communication difficulties complicating diagnosis, how are parents supposed to know whether their child with cerebral palsy has comorbid autism? The problem with diagnosing autism in a child with cerebral palsy includes testing methodology and other factors like the heterogeneity of symptoms associated with both cerebral palsy and autism.
Clinicians often use aids like toys and play-based methods when diagnosing autism. For children with motor function impairments handling of toys may not be possible. Another example is the emphasis of atypical eye gaze as a reg flag for autism—a young child with cerebral palsy may have difficulty lifting their head, therefore, atypical eye contact may not be a symptom of autism but rather a manifestation of poor muscle control.
Some feel children with cerebral palsy are being let down by testing standards that do not take their limitations into consideration. Others speak about the long battle to get their child diagnosed with cerebral palsy, a battle which often leaves parents too weary to seek further diagnosis for possible co-occurring conditions.
No single, definitive test available
Autism and cerebral palsy are conditions that cannot be identified with a definitive test. This means parents need to insist on all available testing (MRI, blood tests, evaluations and assessments). Ideally a multidisciplinary team should assist to ensure a child is diagnosed accurately—and that they receive early, effective and appropriate treatment. This team could include developmental behavioral specialists, neurologists, pediatricians and also physical, occupational and speech therapists.
A knowledgeable team may help a child where standardized testing fails. When assessing signs and symptoms of autism in children with cerebral palsy, a knowledgeable specialist will take their motor skills impairment into consideration. They may look for signs like: insistence on sameness, lack of joint attention, restricted interests, and stimming.
Therapy for co-occurring conditions in a child with cerebral palsy may have a significant effect on their quality of life. Parents may be (understandably) hesitant about accepting another neurodevelopmental diagnosis for their child with cerebral palsy, but the benefits of appropriate therapy for a child’s unique symptoms may help them thrive.
Parents often admit to finding their child “difficult” before an autism diagnosis. Once their child’s neurodiversity is acknowledged and accepted, parents speak of coming to the understanding that it’s the world that is a difficult place for a differently wired brain.
References:
American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). https://doi.org/10.1176/appi.books.9780890425596.
Bjorgaas, Hanne & Elgen, Irene & Ryland, Hilde & Hysing, Mari. (2014). Autism spectrum symptoms in children with cerebral palsy: Prevalence and co-occurring conditions. Research in Autism Spectrum Disorders. 8. 581–588. 10.1016/j.rasd.2014.01.011.
Christine, C., Dolk, H., Platt, M. J., Colver, A., Prasauskiene, A., Krägeloh-Mann, I., & SCPE Collaborative Group (2007). Recommendations from the SCPE collaborative group for defining and classifying cerebral palsy. Developmental medicine and child neurology. Supplement, 109, 35–38. https://doi.org/10.1111/j.1469-8749.2007.tb12626.x
Christensen, D., Van Naarden Braun, K., Doernberg, N. S., Maenner, M. J., Arneson, C. L., Durkin, M. S., Benedict, R. E., Kirby, R. S., Wingate, M. S., Fitzgerald, R., & Yeargin-Allsopp, M. (2014). Prevalence of cerebral palsy, co-occurring autism spectrum disorders, and motor functioning – Autism and Developmental Disabilities Monitoring Network, USA, 2008. Developmental medicine and child neurology, 56(1), 59–65. https://doi.org/10.1111/dmcn.12268.
Craig, F., Savino, R., & Trabacca, A. (2019). A systematic review of comorbidity between cerebral palsy, autism spectrum disorders and Attention Deficit Hyperactivity Disorder.
European journal of paediatric neurology : EJPN : official journal of the European Paediatric Neurology Society, 23(1), 31–42. https://doi.org/10.1016/j.ejpn.2018.10.005.
Shevell M. (2018). Cerebral palsy to cerebral palsy spectrum disorder: Time for a name change?. Neurology, 10.1212/WNL.0000000000006747. Advance online publication. https://doi.org/10.1212/WNL.0000000000006747.
Smile, S., Dupuis, A., MacArthur, C., Roberts, W., & Fehlings, D. (2013). Autism spectrum disorder phenotype in children with ambulatory cerebral palsy: A descriptive cross-sectional study. Research in Autism Spectrum Disorders, 7(2), 391–397. https://doi.org/10.1016/j.rasd.2012.10.008.
