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Infantile spasm: a review article
Mohammad Mahdi Taghdiri1, Hamid Nemati2
1Pediatric Neurology Research Center, Shahid Beheshti University of Medical Sciences (SBMU), Tehran, Iran ; Pediatric Neurology Center of Excellence, Department of Pediatric Neurology, Mofid Children Hospital, Faculty of Medicine, Shahid Beheshti University of Medical Sciences (SBMU), Tehran, Iran.
Insights
Infantile spasms (IS) are a type of seizure in infants, often presenting before age two. This condition, characterized by muscle contractions and EEG abnormalities like hypsarrhythmia, typically has a poor prognosis.
Area of Science:
- Neurology
- Pediatric Neurology
- Epileptology
Background:
- Infantile spasm (IS) is a severe epileptic encephalopathy historically described as West's syndrome.
- It is characterized by brief, symmetric axial muscle contractions (spasms), characteristic electroencephalogram (EEG) abnormalities (hypsarrhythmia), and neurodevelopmental regression.
- IS typically occurs in the first year of life, with a peak onset between 3-7 months, affecting approximately 1 in 2000-4000 live births.
Purpose of the Study:
- To provide a comprehensive overview of infantile spasms (IS), including its clinical presentation, diagnostic hallmarks, and etiological classification.
- To highlight the significance of hypsarrhythmia as the EEG hallmark of IS.
- To differentiate between symptomatic, cryptogenic, and idiopathic classifications of IS based on etiology and developmental status.
Main Methods:
- Review of historical and clinical literature on infantile spasms.
- Description of the characteristic clinical features and EEG patterns (hypsarrhythmia).
- Classification of IS based on etiology: symptomatic, cryptogenic, and idiopathic.
Main Results:
- Infantile spasms present as brief, symmetric axial muscle contractions, often involving flexors and extensors.
- Hypsarrhythmia, a chaotic EEG pattern, is the hallmark of IS.
- The prognosis for IS is generally poor, with most cases occurring before age two.
Conclusions:
- Infantile spasms represent a significant challenge in pediatric neurology due to their severity and poor prognosis.
- Accurate classification into symptomatic, cryptogenic, or idiopathic categories is crucial for understanding the underlying causes and guiding management.
- Early recognition and diagnosis, supported by characteristic clinical and EEG findings, are essential for affected infants.
Objective:
Infantile spasm (IS) is a convulsive disease characterized by brief, symmetric axial muscle contraction (neck, trunk, and/or extremities). IS is a type of seizure that was first described by West in 1841, who witnessed the seizure in his own son. West's syndrome refers to the classic triad of spasms, characteristic EEG, and neurodevelopmental regression. Most cases involve flexors and extensors, but either of the types may be involved independently. IS, as its name implies, most often occurs during the first year of life with an incidence of approximately 1 per 2000-4000 live births. Most, but not all, patients with this disorder have severe EEG abnormalities; this pattern was originally referred to as hypsarrhythmia by Gibbs and Gibbs. Cases with known etiology or signs of brain damage are considered as symptomatic. The Overall prognosis of the disease is poor. Peak onset age of the epileptic syndrome is 3 to 7 months, which mainly occurs before 2 years of age in 93% of patients. Hypsarrhythmia is the EEG hallmark of IS, which comprised a chaotic, bilaterally asynchronous high-voltage polyspike, and slow wave discharges interspersed with multifocal spikes and slow waves. ETIOLOGICAL CLASSIFICATION IS AS FOLLOWS: 1) Symptomatic: with identifiable prenatal, perinatal, and postnatal causes with developmental delay at the presentation time; 2) Cryptogenic: unknown underlying cause, normal development at the onset of spasms, normal neurological exam and neuroimaging, and no abnormality in the metabolic evaluation; 3) Idiopathic: pure functional cerebral dysfunction with complete recovery, no residual dysfunction, normal neuroimaging and normal etiologic evaluation, and normal neurodevelopment.
