Refining Aicardi Syndrome diagnostic Criteria: an expert-based consensus using a modified Delphi approach

Area of Science:

• Neurology
• Genetics
• Developmental Biology

Background:

• Aicardi syndrome (AIC) is a rare neurodevelopmental disorder with historically defined diagnostic features.
• Unclear etiology and evolving diagnostic tools necessitate updated criteria for AIC.
• Previous diagnostic criteria for AIC have been based on individual approaches.

Purpose of the Study:

• To establish the first expert-based consensus on diagnostic criteria for Aicardi syndrome (AIC).
• To integrate existing and novel diagnostic features for AIC.
• To develop consensus on major, supportive, and alert criteria for AIC in clinical practice.

Main Methods:

• A modified Delphi study involving a geographically diverse, multidisciplinary group of 55 expert physicians.
• Achieved consensus on major, supportive, and alert diagnostic criteria for AIC.
• Did not design a fixed diagnostic algorithm due to disease rarity and data heterogeneity.

Main Results:

• Consensus was reached on the historical triad of AIC symptoms.
• New major criteria for AIC include coexisting cerebral malformations and cognitive impairment.
• Additional supportive features and alert criteria (red flags) were identified for AIC diagnosis.

Conclusions:

• The Delphi method successfully achieved expert consensus on AIC diagnostic criteria.
• Limitations include AIC's ultra-rare nature and potential variability in expert experience and representation.
• Ongoing research is needed to validate and refine AIC criteria, especially with advances in genetic and neurological knowledge.