To evaluate the different clinical and etiological patterns of epileptic syndromes in infants and early childhood.

Epilepsy is the most common disabling neurological problem among children worldwide, and has a varying prevalence and etiological profile across the life-cycle. Onset of epilepsy prior to two-year age is more common than later in childhood.

It more commonly has a symptomatic cause and poor long-term outcome with respect to seizure-control and cognition. Previous work from India on epilepsy in infants has either focused on a single etiology, on one particular epilepsy syndrome, or on single seizure rather than epilepsy.

A recent prospective, population-based study showed an incidence of 75 per 100 000 live births prior to 6 months and 62 per 100 000 between 6 and 12 months, considerably higher than previous estimates from retrospective studies. These population-based studies are from high-resource countries, and it is noteworthy that acquired epilepsies have a higher incidence in resource-limited populations.

Traditionally, syndromes have been defined primarily by electroclinical features; however, in the last two decades, gene discovery in the epilepsies has allowed cohorts of cases with a shared genetic etiology to be studied. Consistent electroclinical phenotypes have emerged, with examples including CDKL5, MeCP2, PCDH19, STXBP1, and inv dup 15.

An epileptic syndrome is "an epileptic disorder characterised by a cluster of signs and symptoms customarily occurring together; these include such items as the type of seizure, aetiology, anatomy, precipitating factors, age of onset, severity, chronicity, diurnal and circadian cycling, and sometimes prognosis. However, in contradistinction to a disease, a syndrome does not necessarily have a common aetiology and prognosis.

An epilepsy syndrome is "a complex of signs and symptoms that define a unique epilepsy condition. This must involve more than just the seizure type; thus, for instance, frontal lobe seizures per se do not constitute a syndrome.

Furthermore, some structural, metabolic, immune, and infectious etiologies also have characteristic electroclinical phenotypes. Therefore, epilepsies due to specific genetic, structural, metabolic, immune, or infectious etiologies may also meet criteria for a syndrome, when they are associated with consistent electroclinical features and have management and prognostic implications. Epilepsies in children younger than 3-years-old can be classified by syndrome in 54% of patients and by etiology in 54%, when the latest neuroimaging, metabolic, and gene testing techniques are used. In the group younger than 12 months, etiology could be determined in 64%. By comparison, infants with severe epilepsies beginning before 18 months can be classified with an epilepsy syndrome at presentation in 64%, with the etiology being determined in 67%.

The concept of the "developmental and epileptic encephalopathy" (or DEE) recognizes that in infants presenting with severe early-onset epilepsy, neurodevelopmental comorbidity may be attributable to both the underlying cause and to the adverse effects of uncontrolled epileptic activity.

Children presenting with epilepsy very early in life experience a high burden of cognitive and behavioral comorbidity, and higher rates of drug resistance and mortality, with up to 50% showing global developmental delay 2 years after presentation. Comorbidities are more frequent among children who develop drug-resistant seizures and those with a high seizure burden.

Inclusion Criteria:

For each group

• Infants and children diagnosed as epilepsy syndrome (as per International League Against Epilepsy, 2014).
• Infants and children ages ranged between 1 & 36 months.

Exclusion Criteria:

for each group

• Patients with epilepsy less than 1 month and more than 36 months.
• Patients with conditions mimic epilepsy.
• Patients with seizures related to electrolyte disturbances, inborn error of metabolism, mitochondrial diseases, white matter diseases, neurodegenerative diseases, peroxisomal disorders and non-syndromic epileptic children.

The cases will be chosen during the Child Neurology Outpatients Consults in pediatric neurology units of Al-azhar and Child Assiut University Hospitals. Based on clinical data, the patients will be divided into different epilepsy syndromes.