Is Chiari type I malformation a reason for chronic daily headache.

This article briefly reviews the spectrum of headaches associated with Chiari type I malformation and specifically analyzes current data on the possibility of this malformation as an etiology for some cases of chronic daily headache (CDH). Chiari type I malformation is definitely associated with cough headache and not with primary episodic headaches, with the rare exception of basilar migraine-like cases. With regard to CDH, there is no clear evidence supporting an association with this malformation. An MRI study would be justified only in patients showing either a Valsalva-aggravating component or cervicogenic features. Hydrocephalus and low intracranial pressure syndrome should be ruled out in patients showing tonsillar herniation in an MRI study and consulting due to daily headache.