ENOrphanet Journal of Rare Diseases | A Systematic Review of Clinical Features of Infantile Epileptic Spasms Syndrome
日期: March 07, 2026
分类: Frontiers
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This study systematically reviewed clinical features of 3,786 patients with Infantile Epileptic Spasms Syndrome (IESS) across 140 studies, comprehensively summarizing 25 clinical manifestations, providing critical evidence for early recognition and timely referral.
Literature Overview
The article titled 'Clinical features of Infantile Epileptic Spasms Syndrome: a systematic review', published in the Orphanet Journal of Rare Diseases, reviews and summarizes 140 studies on Infantile Epileptic Spasms Syndrome (IESS) from 1979 to July 2024, systematically analyzing clinical features of 3,786 IESS patients. The study found that the most common clinical manifestations include flexor spasms (48.28%), mixed spasms (30.19%), and extensor spasms (10.49%), while identifying 19 low-frequency symptoms. The article highlights the limitations of current clinical recognition tools and proposes the development of more comprehensive screening instruments to support early referrals by pediatricians. This study provides a key evidence base for improving early diagnosis rates of IESS.Background Knowledge
Infantile Epileptic Spasms Syndrome (IESS), also known as West syndrome, is a severe epileptic disorder in infants characterized by epileptic spasms, hypsarrhythmia on electroencephalogram (EEG), and developmental stagnation or regression. The disease typically presents between 1 month and 2 years of age, and without timely treatment, it may lead to severe neurodevelopmental impairments. Although early intervention (within 7 days of symptom onset) can significantly improve outcomes, clinical diagnosis is often delayed, with an average delay of 1 month and some cases exceeding 3 months. Currently, the American Academy of Pediatrics (AAP) lists only five typical symptoms, which are insufficient to cover the diverse manifestations of IESS. Furthermore, diagnosis of IESS relies on EEG, particularly long-term EEG during sleep, but most studies fail to report EEG monitoring duration or whether sleep data were included, affecting diagnostic accuracy. As IESS is a rare disease, existing research consists mostly of small-sample descriptive studies, lacking high-quality controlled studies, thus limiting the strength of evidence. This systematic review fills the gap in comprehensive clinical descriptions of IESS and provides a solid foundation for future screening tool development and clinical training.
Methods and Experiments
The research team followed the PRISMA guidelines to systematically search the MEDLINE Complete and Embase databases for literature published between 1979 and July 31, 2024. Inclusion criteria were: original studies published in English, patients aged 1 month to 2 years, and reporting clinical features of IESS. Reviews, conference abstracts, and non-English articles were excluded. Two researchers independently screened titles and abstracts, followed by full-text assessments, using the Rayyan QCRI tool to manage the screening process. Data extraction included author, year, country, sample size, sex, race, study design, diagnostic tools, age at onset, age at diagnosis, and clinical features. Inter-rater reliability was assessed using Gwet’s AC1. Methodological quality was evaluated via the Methodological Quality Score (MQS), covering sample size, reporting of sex, and reporting of onset and diagnosis ages, with scores ranging from 2 to 10.Key Findings and Insights
Research Implications and Outlook
This study is the first to systematically summarize all clinical features of IESS, revealing the limitations of the current AAP symptom checklist and emphasizing the need for more comprehensive screening tools to assist primary care physicians in recognizing IESS. It is recommended that videos of typical symptoms be included in continuing medical education to enhance pediatricians’ awareness of IESS. The study also calls for future research to report EEG monitoring duration and sleep status to improve diagnostic accuracy. Additionally, multicenter collaborative studies should be promoted to accumulate larger samples and conduct analytical or controlled studies to identify IESS-specific clinical biomarkers.
Conclusion
This systematic review comprehensively summarizes the clinical features of Infantile Epileptic Spasms Syndrome (IESS), identifying 25 distinct manifestations in 3,786 patients, with flexor spasms, mixed spasms, and extensor spasms being the most common. The study reveals high clinical heterogeneity in IESS and shows that existing symptom checklists fail to cover most low-frequency manifestations, leading to widespread diagnostic delays. Although early intervention can significantly improve outcomes, only a few studies currently provide complete diagnostic timeline information, and EEG monitoring details are poorly reported. The study emphasizes the need to develop standardized IESS screening tools and incorporate video examples to enhance recognition by frontline physicians. Moreover, future research should adopt more rigorous methodological designs, including large-sample, multicenter studies, and standardize the reporting of EEG monitoring parameters. This review provides critical evidence to support early recognition, timely referral, and future research design for IESS, helping to shorten the diagnostic gap and improve neurodevelopmental outcomes in affected children.
