We reviewed the characteristics of headache in patients with cerebral autosomal 
dominant arteriopathy with subcortical infarcts and leukoencephalopathy 
(CADASIL), to verify the appropriateness of the International Classification of 
Headache Disorders, second edition (ICHD-II) criteria. Available data were found 
through Medline/PubMed using the keyword "cerebral autosomal dominant 
arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)". The 
search was restricted to studies published in English in the years between 1993 
and 2008. We excluded studies that did not report original data on CADASIL and 
information regarding the presence of headache. We found 34 studies reporting 
data on 749 patients overall; 387 (51.7%) patients had headache. According to 
the authors' definition, 356 (92%) patients were reported as having migraine and 
31 (8%) as having headache. Of the 356 patients who were defined as migraineurs, 
125 (35.1%) had migraine with aura, 7 (2%) migraine without aura, 156 (43.8%) 
unspecified migraine and 68 (19.1%) had more than one type of migraine. Among 
the 31 patients reported as suffering from headache, the headache was not 
further detailed in 18 (58.1%) patients; it was defined as chronic in 6 (19.3%), 
as resembling migraine with aura in 4 (12.9%), as resembling migraine without 
aura in 2 (6.5%) and as tension type in 1 (3.2%) patient. In patients with 
CADASIL, the headache was usually referred to as migraine and mostly as migraine 
with aura. However, this referral is formally incorrect since the diagnostic 
criteria for any type of migraine in the ICHD-II require that the disturbance is 
not attributed to another disorder. For this reason, we suggest updating the 
ICHD-II in relation to CADASIL. Our suggestion is to insert a new category 
referred to as Headache attributed to genetic disorder including Headache 
attributed to CADASIL.