Chicago—In 1891, when Hans Chiari, MD, published his first account of abnormalities in the brain at the craniocervical junction, the Austrian pathologist could hardly have imagined the questions his work eventually would raise.
Chiari discovered these anomalies while performing postmortem examinations on children and adolescents with cerebral hydrocephalus. He described the irregularities as “cone-shaped projections” of the cerebellum that protruded below the foramen magnum and into the spinal canal (Bejjani GK. Neurosurg Focus. 2001;11:1-8). Chiari recognized that the degree of these structural defects in the brain was not related to the severity of the hydrocephalus. But he offered no wholesale explanation for their cause, leaving physicians and scientists puzzled for more than a century about the etiology, diagnosis, and optimal treatment of what today is known as Chiari malformation.
Voelker R. Chiari Conundrum: Researchers Tackle a Brain Puzzle for the 21st Century. JAMA. 2009;301(2):147-149. doi:10.1001/jama.2008.915