noted that early research has linked Chiari with abnormalities on chromosomes 2, 5, and 9. “This is still in the primitive stages,” he said. The working group on pathophysiologysuggestedinitiatingageneticmapping project, while conceding that this wouldbeamassiveundertaking.“There’s a major knowledge deficit in the genetic partofthisdisorder,”saidSpyridonSgouros, MD, of the University of Athens, Greece,whomoderatedthegroup.Buthe noted that such a project would require large numbers of patients. Sgouros also said his group recognized the need for more research to find a measurable component of the condition that correlates with symptoms— studies have shown that the length of the cerebellar tonsils is not consistently linked with symptom severity. His group also called for greater consensus on terminology. Because the 4 types of Chiari malformation represent a wide range of structural abnormalities, some experts have debated the need for such subclasses as type I.5. Others have questioned whether type IV really can be considered Chiari malformation. And some say the condition should be renamed to reflect its hallmark—tonsillar herniation— rather than the role of Hans Chiari. Sgouros suggested the need for a consensus conference to arrive at unified terminology, but expressed doubt that one would be organized.