Cognitive disorders in childhood epilepsy: a comparative longitudinal study using administrative healthcare data

Abstract

Objective: The study aimed to assess the risk of cognitive impairment in patients with epilepsy, the impact of age of epilepsy onset on cognition and the temporal relationship of epilepsy onset and intellectual impairment.

Methods: This longitudinal study analyzed birth cohorts and followed-up children born 2005-2007 up to the age of ten using administrative healthcare data of about 8.9 million members insured by the statutory health insurance "BARMER" in Germany. We compared prevalence of cognitive impairment (ICD-code F7*) in children with epilepsy (ICD-code G40) to controls, and calculated relative risks by age groups at onset of epilepsy and assessed differences in relation to the temporal sequence of the diagnoses.

Results: Of the 142,563 pre-pubertal children included in the analysis, 2728 (1.9%) had an epilepsy diagnosis within the first 10 years of life. 17.4% (475/2728) of children with epilepsy had a diagnosis of cognitive impairment compared to 1.7% (2309/139835) in controls. The relative risk for cognitive impairment compared to age-matched controls was 10.5 (95% CI 9.6, 11.6) and was highest in epilepsy cases with seizure manifestation within the first 2 years of life compared to older children. The prevalence of cognitive impairment before epilepsy diagnosis was slightly increased compared to controls, while it was increased by a factor of nine in children diagnosed with cognitive impairment in the year of onset of epilepsy or afterwards.

Conclusions: Pre-pubertal children with epilepsy have a ten-fold higher risk for intellectual impairment compared to age-matched controls. This risk inversely correlates with the age of epilepsy manifestation. Cognitive impairment was diagnosed after epilepsy manifestation in the majority of patients.

Keywords: Children; Cognition; Epilepsy.

Fig. 1

Flowchart showing the study population of children up to the age of ten with/without epilepsy. A total of 142,563 individuals were available for primary analysis

Fig. 2

The incidence rate of pre-pubertal epilepsy. The incidence rate of pre-pubertal epilepsy is highlighted in blue, the upper and lower confidence intervals are depicted in gray. The highest incidence rate was reported at the age of 1 year

Fig. 3

The risk of cognitive impairment in children with epilepsy compared to age-matched controls. The risk of cognitive impairment was increased by factor 10.5 in patients with epilepsy. Epilepsy patients revealed most likely not further specified (F78, 79) or mild (F70) cognitive impairment. The risk of profound cognitive impairment (F73) was almost increased by factor 50 compared to age-matched controls

Fig. 4

Risk of cognitive impairment in children with epilepsy compared to controls by age groups. There is a gradual increased absolute and relative risk for toddlers with epilepsy to have cognitive impairment compared to preschool—and school children

Fig. 5

Risk of cognitive impairment before and after epilepsy diagnosis compared to the general risk of cognitive impairment. The majority of patients received the diagnosis of cognitive impairment after the diagnosis of epilepsy