Roughly 4% of the population is affected by a congenital brain malformation that has eluded researchers' efforts to find causes and treatments. For the condition, Chiari type-1 malformation, the diagnosis is straightforward: the lower part of the brain, known as the cerebellum, protrudes at least five millimeters through the gap in the skull that connects to the spinal cord. There's no one known cause for Chiari type-1, and the symptoms it can cause are unpredictable.
The most common problems include chronic headaches, difficulty swallowing and decreased muscle strength, as well as syringomyelia, a condition that occurs when a cyst forms in the spinal cord. Sometimes these symptoms occur in combination, or singly. In most cases, people can live their whole lives with no ill effects.
The breadth of Chiari type-1 presentations has made it difficult for physicians to develop a consistent treatment protocol for their patients. A study by Washington University in St. Louis researchers has begun to fill that gap.
A collaboration among neurosurgeons and computer scientists has defined three sub-types of Chiari type-1 with distinct characteristics that physicians can use to plan treatment options for their patients. The results are available in the journal Neurosurgery. More and better information was needed to refine Chiari type-1 diagnoses so doctors could reliably determine which cases call for which clinical interventions, if any.
For instance, a surgical operation can widen the .