The Challenge of Recognizing Pediatric Cataplexy
While cataplexy is rare, experts agree that it is important for health care providers to recognize it and to know that its presentation differs in adults and children. This difference is important because it contributes to diagnostic delays and potential misdiagnoses. Moreover, the diagnosis of cataplexy may be the first clue that a patient has narcolepsy, a disorder that takes a median of nine years to be diagnosed, and for which there are now several treatment options. Not only is cataplexy commonly seen in children with narcolepsy, but it can also be caused by other conditions such as Prader-Willi Syndrome, Niemann-Pick type C, and lesions in the hypothalamic or pontomedullary regions of the brain.
In children, cataplexy attacks may resemble clonic, atonic, and/or myoclonic seizures. Alternatively, at onset, cataplexy may present as persistent hypotonia and or/complex hyperkinetic movements. Often children with cataplexy have prominent facial involvement that can include active movement of the tongue and perioral muscles. Moreover, unlike adults, children often experience cataplexy without a clear emotional trigger.
A recent case report described a boy aged eight years who was admitted to the hospital for symptoms of daytime sleepiness. He was hospitalized with a prediagnosis of meningoencephalitis and acute disseminated encephalomyelitis (ADEM). After many tests, the boy was discharged with a follow-up appointment with pediatric psychiatry for hallucinations and depression. Seven months later, the boy presented to the hospital again, this time with cataplexy in the form of head dropping attacks. The hospital admitted the child with a prediagnosis of epilepsy, subacute sclerosing panencephalitis (SSPE), and autoimmune encephalitis. As is common with pediatric narcolepsy, the patient experienced a 10 kg increase in body weight over approximately one year. His diagnosis of narcolepsy and cataplexy took thirteen months from first presentation. Once diagnosed with narcolepsy with cataplexy, he received treatment and responded with a reduction of symptoms and normalization of body mass index.
In recognition that cataplexy can be difficult to diagnose in children, researchers at Jazz Pharmaceuticals and elsewhere have developed the Epworth Sleepiness Scale for Children and Adolescents (ESS-CHAD). The ESS-CHAD can be used in combination with a cataplexy diary to diagnose children with narcolepsy and cataplexy and the two are currently being used in a Phase III, placebo-controlled clinical trial of sodium oxybate in children and adolescents with narcolepsy.
In designing these assessments, the researchers identified subtle differences in the way the symptoms were described by patients versus their parents/caregivers. Specifically, parents were not as good as their children at recognizing cataplexy symptoms/triggers. The researchers thus created a child-friendly definition of cataplexy that could be used in an electronic cataplexy daily diary designed for evening administration and self-completion by patients ≥ 9 years old. The electronic cataplexy diary includes this statement:
Cataplexy is a sudden feeling of weakness in your legs, arms, head or face. It can be different for each person. These are some examples of cataplexy:
Falling down or feeling weak in my legs
Feeling weak in my arms or like I couldn’t move my arms
My face doing weird things (for example: my tongue sticking out, mouth opening, eyes closing or eyes rolling)
My head dropping or feeling like I couldn’t hold my head up
Yes, I had cataplexy today
No, I did not have cataplexy today
The hope is that these tools, in combination with increased awareness in health care providers and patients, will facilitate the diagnosis of cataplexy in children, many of whom live with the label of being “lazy.” Early diagnosis will allow the families to receive prompt and multidisciplinary management and the children to, perhaps, reclaim their childhood.
References:
Maski K and Owens J. Pediatric Sleep Disorders. Continuum (Minneap Minn). 2018. 24:210-227.
Pillen S, Pizza F, Dhondt K, et al. Cataplexy and Its Mimics: Clinical Recognition and Management. Curr Treat Options Neurol. 2017. 19:23.
Postiglione E, Antelmi E, Pizza F, et al. The Clinical Spectrum of Childhood Narcolepsy. Sleep Med Rev. 2018. 38:70-85.
Savas T, Erol I, Saygi S, et al. Narcolepsy and Cataplexy: A Pediatric Case Report. Turk. Pediatri. Arsivi. 2016. 51:221-223.
Wang YG, Benmedjahed K, Lambert J, et al. Assessing Narcolepsy with Cataplexy in Children and Adolescents: Development of a Cataplexy Diary and the ESS-CHAD. Nat Sci Sleep. 2017. 9:201-211.
Yanagishita T, Ito S, Ohtani Y, et al. Two Cases of Childhood Narcolepsy Mimicking Epileptic Seizures in Video-EEG/EMG. Brain Dev. Published online May 15, 2018.
