Comorbidities of Epilepsy in Persons with PMS: Results from the Rare Epilepsy Network

By Geraldine Bliss
PMSF Board Member and mom to Charles

In 2014 PMS families whose children have epilepsy were invited to participate in the Rare Epilepsy Network (REN), a registry of rare epilepsies. The REN conducted a study to describe the prevalence and characteristics of comorbidities (the simultaneous presence of two or more chronic diseases or conditions in a patient) of persons with rare epilepsies. Nearly all persons with rare epilepsies are medically complex, with a high prevalence of multiple comorbidities.

The study included a total of 795 participants, representing more than 30 rare epilepsy diagnoses/syndromes, including 29 patients with Phelan-McDermid syndrome.

Below we have abstracted the findings of greatest relevance to individuals with PMS who have been diagnosed with epilepsy.

• The most commonly reported comorbidity classes were 71% with learning/developmental disability, 71% with mental health or behavioral issues, 60% with sleep disorders, 52% with brain abnormalities, and 49% with oral or dental issues. The prevalence of learning disability, mental health issues, and oral/dental issues were significantly different across the diagnoses (all P < .01). The highest prevalence of these 3 comorbid classes was found in Phelan-McDermid syndrome, which included 100% with learning disability, 96% with mental health issues, and 78% with oral/dental issues.
• The overall prevalence of gastrointestinal, cardiac, and endocrine disorders were 28%, 21%, and 19% respectively, with significantly differing prevalence across diagnoses (P < .0001 for all). The highest combined prevalence of gastrointestinal, cardiac, and endocrine disorders was 66% in Phelan-McDermid Syndrome, 40% in tuberous sclerosis complex, and 65% in hypothalamic hamartoma. On average, participants had more than 1 gastrointestinal issue (mean, 1.2) and persons with Phelan-McDermid syndrome and Aicardi syndrome had more than 2 gastrointestinal issues (mean, 2.8 and 2.3, respectively). Among persons with gastrointestinal, cardiac, and endocrine disorders respectively, 89% had constipation, 51% had clammy/cold hands and feet, and 67% had heat sensitivity.
• The prevalence of hearing, respiratory, immune, and mitochondrial disorders were low (all ≤16%) and similar across diagnoses, except for a relatively high (35%) prevalence of hearing disorders and a 36% prevalence of immune disorders in Phelan-McDermid syndrome. In these persons, among the most commonly reported respiratory and immune comorbidities, 35% had aspiration pneumonia and 24% had lymphedema.

Comorbidities should be carefully considered in the diagnosis and management of persons with epilepsy.

Your child’s doctor may be able to pull up the full text of the published findings here:

PMSF | Phelan-McDermid Syndrome Foundation