Seizures | - Seizures are characterized by focal tonic features at onset, affecting the head, face, and limbs. Focal clonic or tonic seizures may alternate sides from seizure to seizure, and may evolve to bilateral tonic or clonic seizures.
| - Clinical history suggestive of in utero seizures
| - Epileptic spasms
- Myoclonic seizures
- Generalized tonic seizures
- Generalized tonic-clonic seizures
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EEG | | - Interictal: Mild background slowing
| - Interictal:
- Persistent focal slowing or moderate or greater background slowing not limited to the postictal period
- Burst suppression pattern
- Hypsarhythmia
- Ictal: Lack of EEG correlate with clinical symptoms
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Development at onset | | | - Any degree of encephalopathy
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Imaging | | | - Neuroimaging documenting a causal lesion for seizures
|
Other testing (eg, genetics) | | - Lack of pathogenic variant in gene associated with this syndrome, most commonly KCNQ2 or KCNQ3
- Lack of family history suggesting AD inheritance with incomplete penetrance
| - Other acute symptomatic cause of seizures including intracranial infection, ischemic or hemorrhagic stroke, hypoxic-ischemic brain injury, significant metabolic disturbances
|
Course of illness | | - Mild neurodevelopmental delay long-term
- Lack of remission of epilepsy after 6 months of age
- Drug-resistant epilepsy
| - Moderate to severe neurodevelopmental disability
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Syndrome without laboratory confirmation: In resource-limited regions, SeLNE can be diagnosed without EEG and MRI in a neonate with a family history suggestive of familial SeLNE who meets all other mandatory and exclusionary clinical criteria and has no alerts. However, the clinical history of affected family members should be consistent with the expected course for SeLNE, and careful follow-up of the patient is required to ensure their course is also consistent with this syndrome. |