Risk factors of epilepsy severity in institutionalized adults with profound intellectual and multiple disabilities from childhood

This study aimed to identify risk factors for epilepsy severity in institutionalized adults with profound intellectual and multiple disabilities. We analyzed patients aged 20 years or older who were institutionalized in two long-term care facilities because of profound intellectual and multiple disabilities from childhood. We examined the relationship between epilepsy severity and possible risk factors, such as patients’ clinical characteristics (e.g., cause and level of disability), brain imaging and electroencephalography findings, and antiseizure drug treatment. Epilepsy severity was classified into five levels according to seizure frequency. We compared patients aged < 40 years (younger group) and those aged ≥ 40 years (older group) according to the fact that the average life expectancy for individuals with profound intellectual and multiple disabilities typically ranges from 40 to 60 years. We recruited 151 patients, with a median age of 44 years (range, 20−74 years). The cause of disability was congenital or unknown factors in 89 patients (58.9%), perinatal brain damage in 45 (29.8%), and acquired brain injury in 17(11.3%). The relationship between age and epilepsy severity differed between the two age groups. In patients aged < 40 years, those with most severe group (Severity 5) were significantly older than those with milder group (Severity 2) (p = 0.010) and second severe group (Severity 4) (p < 0.01). Conversely, in patients aged ≥ 40 years, those with most mild group (Severity 1) were significantly older than those with Severity 4 (p = 0.027). Epilepsy tended to be more severe in patients with more profound disability, those with a greater extent of diffuse abnormalities on brain imaging, and those who had developed myoclonus. In older group, the presence of focal epileptic paroxysms was an independent risk factor for epilepsy severity. Epilepsy severity in adults with profound intellectual and multiple disabilities follows a divergent age-dependent trend, showing an increase before age 40 and a potential decline thereafter. Brain dysfunction and diffuse imaging abnormalities remain consistent risk factors across all ages. The presence of focal epileptic paroxysms on electroencephalography was a specific risk factor for severe epilepsy in patients aged ≥ 40 years. ● ·In the younger group (< 40 years), the most severe epilepsy group (Severity 5) showed a significantly higher mean age than milder group (Severity 2) and second severe group (Severity 4). Conversely, in the older group (≥ 40 years), the mildest group (Severity 1) was significantly older than the severe group (Severity 4). These findings suggest a non-linear relationship between age and epilepsy severity. ● ·Severity of epilepsy tended to be higher in patients with a higher degree of intellectual and physical disability. ● ·Epilepsy severity was significantly higher in those who had focal epileptiform discharges in patients 40 years or older.