Global burden of early-life epilepsy remains substantial, with developmental and epileptic encephalopathies leading the count
Population-based evidence now places neonatal and infantile-onset epilepsy among the most consequential early-life neurologic disorders worldwide. In a systematic review and meta-analysis of 86 studies from 30 countries, the pooled cumulative incidence of infantile-onset epilepsies within the first 2 years of life reached 236.0 cases per 100,000 live births, with wide uncertainty around that estimate. The breadth of the confidence interval and the even wider prediction interval make the clinical message hard to ignore: early-life epilepsy is neither rare nor evenly distributed across the world.
The burden was driven most strongly by developmental and epileptic encephalopathies, a group in which seizures and underlying brain dysfunction reinforce one another during a critical window of neurodevelopment. Across syndrome subgroups, DEEs had the highest incidence at 67.7 cases per 100,000 live births. Within that category, infantile epileptic spasms syndrome emerged as the most incident disorder, at 31.6 cases per 100,000 live births. In practical terms, this places IESS at the center of the global early-onset epilepsy burden, where delayed recognition can translate into lost developmental opportunity, persistent seizures, and a heavier long-term disability load.
Infantile epileptic spasms syndrome dominated the DEE signal.
A disease pattern shaped by early brain vulnerability
The epidemiology fits the biology. Neonatal and infantile epilepsies arise during periods of rapid synaptic development, network maturation, and myelination, when seizures may be both a manifestation of an underlying lesion and a force that further disrupts development. DEEs sit at the severe end of that spectrum because the epileptic activity itself is often intertwined with the neurobiologic substrate. In that setting, incidence is not just a count of seizures; it is an indirect measure of how often fragile early brain circuits are pushed into pathological synchronization.
Among self-limited epilepsies, self-limited infantile epilepsy had the highest incidence, at 13.0 cases per 100,000 live births. Even this lower-severity subgroup matters clinically because recognition still affects counseling, diagnostic intensity, and treatment selection. Families and clinicians need early distinction between syndromes with a more favorable course and those in which seizures are an early marker of broader neurologic injury. A delay of even weeks can change the trajectory when spasms, regression, or recurrent seizures are already eroding developmental reserve.
Heterogeneity limits precision but not concern
The authors used population-based observational studies, searched four major databases through December 18, 2025, and pooled incidence and prevalence estimates with generalized linear mixed-model random-effects meta-analysis. They also examined subgroup patterns by country, World Health Organization region, World Bank income, and diagnostic criteria, and used metaregression to explore study-level influences on infantile-onset epilepsy syndromes. This approach is methodologically robust for a field in which definitions, case capture, and follow-up practices vary widely across settings.
Still, the heterogeneity was substantial. The prediction interval for infantile-onset epilepsies spanned from 53.0 to 1044.3 cases per 100,000 live births, a range that signals how differently the condition may be detected and reported from one setting to another. Such spread can reflect true differences in risk, but it can also arise from case ascertainment, access to electroencephalography, genetic testing availability, referral pathways, and survival patterns. For clinicians, the result is not a single global number to quote with false confidence. It is a reminder that local epidemiology can diverge sharply from pooled estimates when surveillance systems are uneven.
Geographic blind spots leave major questions unanswered
The regional distribution of the evidence was uneven. Most studies came from high-income countries in the European Region, while data from the African and Eastern Mediterranean Regions were notably sparse. That imbalance matters because neonatal and infantile epilepsies do not occur in a vacuum. Perinatal injury, infection, consanguinity patterns, health-system access, and survival after brain injury all shape the observed burden. A literature dominated by high-income settings may understate the full epidemiologic weight in places where diagnostic infrastructure is limited and mortality after severe early-onset epilepsy may be higher.
This is where incidence and prevalence begin to tell different stories. Incidence captures how many children develop disease; prevalence reflects who survives with it. In disorders with significant early mortality, prevalence may fall even when incidence is high. The study’s call for longitudinal research on survival, remission, and functional outcomes is therefore not academic fine print. It is essential to understanding how many infants are living with ongoing seizures, developmental impairment, and treatment exposure after the initial diagnosis.
Why these numbers matter at the bedside
For pediatric neurologists, neonatologists, and general clinicians, the findings reinforce the need for early seizure recognition systems in newborn nurseries, emergency departments, and primary care. The first year of life is a narrow therapeutic window in which epileptic spasms, focal seizures, and syndromic epilepsies can present subtly. Misattribution to colic, startle, reflux, or benign sleep phenomena still delays care in real-world practice. Earlier diagnosis can change the treatment course, especially when the syndrome is one in which prompt control may preserve developmental potential.
The data also argue for syndromic thinking rather than seizure counting alone. Early-onset epilepsy is not one disease, and the prognosis depends heavily on whether the child has a self-limited syndrome, a structural cause, a genetic epilepsy, or a broader epileptic encephalopathy. Public health planning, genetic counseling, and resource allocation all depend on that distinction. Without population-based surveillance in underrepresented regions, the global map remains incomplete, and the children most at risk may be the least visible in the literature.
The study stops short of providing a precise universal rate because the underlying evidence is too uneven for that. It does, however, establish a consistent pattern: neonatal and infantile-onset epilepsies are globally important, DEEs account for a large share of the burden, and IESS is the dominant syndrome within that severe category. What remains missing is not the signal, but the geographic coverage, longitudinal outcome data, and region-specific epidemiology needed to translate incidence into durable care planning.