Related Experiment Video
Updated: Apr 11, 2026

Behavioral Characterization of Pentylenetetrazole-induced Seizures: Moving Beyond the Racine Scale
Published on: July 8, 2025
Etiology and Long-Term Outcomes of Late-Onset Infantile Spasms
Liisa Metsähonkala1, Eija Gaily1, Leena Valanne2
1Epilepsy Unit, Department of Pediatric Neurology, Helsinki University Hospital, Helsinki, Finland.
Objectives:
The purpose of the study was to evaluate the etiology and long-term outcomes of late-onset epileptic spasms (LOS).
Methods:
This is a retrospective analysis of all consecutive patients seen at our center with onset of clusters of epileptic spasms between 1 and 3 years of age in 1995 through 2005.
Results:
Overall, 17 children with LOS were identified. Overall, 14 children (82%) had structural etiology. Six patients received resective surgical treatment. Five had focal cortical dysplasia type 1 (FCD1) histology (29% of all the patients). Overall, 16 children were followed for 2 to 18 years. At the latest follow-up, seizure freedom was observed in 67% of the operated and in 50% of the nonoperated patients. Normal cognition or only mild mental deficiency was observed in nine patients (56%), of whom eight were seizure-free. All patients with intractable spasms had a severe mental deficiency.
Conclusion:
The overall cognitive outcome of LOS was more favorable than in the previous reports and was associated with seizure freedom. FCD1 is a frequent etiology for LOS and the cognitive outcome of patients with FCD1 seemed to be favorable.
More Related Videos
09:57Author Spotlight: Advancing Pediatric Epilepsy Surgery in Children Through Novel Biomarkers and Enhanced Localization
Published on: September 20, 2024
07:36Modeling Encephalopathy of Prematurity Using Prenatal Hypoxia-ischemia with Intra-amniotic Lipopolysaccharide in Rats
Published on: November 20, 2015
Related Concept Videos
Seizures: Classification
Seizures are typically classified into two main categories: focal and generalized seizures.
Focal Seizures
Focal seizures originate from specific regions of the brain. These seizures are further sub-classified into two types:
Epilepsy and Seizures: Overview
Various factors can trigger epilepsy, including genetic factors, brain damage, metabolic causes, and unknown etiology. Diagnosis of epilepsy involves electroencephalography (EEG), which...
Antiepileptic Drugs: Modulators of Neurotransmitter Release Mediated by SV2A Protein
SV2A is a transmembrane glycoprotein located predominantly in the brain, modulating the release of neurotransmitters for neuronal communication. Both levetiracetam and brivaracetam exhibit a high affinity for...
Spasmolytic Agents: Chemical Classification
A major class of centrally acting spasmolytics is the α2-agonist, such as tizanidine. These drugs bind to α2-adrenoceptors, inhibiting the release of the excitatory neurotransmitter glutamate. They also...
Long-term Potentiation
Hebbian LTP
LTP can occur when...
Long-term Potentiation