A trigger (from the Dutch trekken, meaning to pull) is a lever which, when pulled by the finger, releases the hammer on a firearm. In a database, a trigger is a set of Structured Query Language (SQL) statements that automatically fires off an action when a specific operation, such as changing data in a table, occurs. A trigger consists of an event (an INSERT, DELETE, or UPDATE statement issued against an associated table) and an action (the related procedure).
Other conditions sometimes associated with Chiari malformation include hydrocephalus, syringomyelia, spinal curvature, tethered spinal cord syndrome, and connective tissue disorders such as Ehlers-Danlos syndrome and Marfan syndrome. Chiari malformation is the most frequently used term for this set of conditions.
Diagnosis of Chiari is often made as the result of routine x-ray, MRI or CT imaging of the skull and upper neck or the lumbar spine, often for Migraine or other disorders. 3D CTA and 3D MRI are preferred for the doctorâs best impression and diagnosis of Chiari malformation as well as surgical preparation.