The commentary by Bradstreet, Ruggiero, and Pacini discusses the structural and functional features of central nervous system (CNS) lymphatic vessels, particularly in the context of autism spectrum disorders (ASD). The authors highlight the recent discovery of a meningeal lymphatic system, which provides a secondary pathway for immune cell trafficking through the CNS to deep cervical lymph nodes. This finding challenges traditional views on brain tolerance and immune privilege, suggesting that neuroinflammation may play a significant role in ASD pathogenesis. The commentary also emphasizes the importance of increased extra-axial fluid (EAF) in ASD, which can be measured using transcranial ultrasonography. The authors suggest that chronic infections and inflammation may lead to impaired meningeal lymphatic drainage, contributing to increased EAF and cortical dysplasia. They propose that this drainage deficit could be a key factor in the development of ASD symptoms and recommend further research into the role of meningeal lymphatics in ASD pathogenesis.The commentary by Bradstreet, Ruggiero, and Pacini discusses the structural and functional features of central nervous system (CNS) lymphatic vessels, particularly in the context of autism spectrum disorders (ASD). The authors highlight the recent discovery of a meningeal lymphatic system, which provides a secondary pathway for immune cell trafficking through the CNS to deep cervical lymph nodes. This finding challenges traditional views on brain tolerance and immune privilege, suggesting that neuroinflammation may play a significant role in ASD pathogenesis. The commentary also emphasizes the importance of increased extra-axial fluid (EAF) in ASD, which can be measured using transcranial ultrasonography. The authors suggest that chronic infections and inflammation may lead to impaired meningeal lymphatic drainage, contributing to increased EAF and cortical dysplasia. They propose that this drainage deficit could be a key factor in the development of ASD symptoms and recommend further research into the role of meningeal lymphatics in ASD pathogenesis.