J. Rothrock et al., DEMOGRAPHIC AND CLINICAL CHARACTERISTICS OF PATIENTS WITH EPISODIC MIGRAINE VERSUS CHRONIC DAILY HEADACHE, Cephalalgia, 16(1), 1996, pp. 44-49
We compared data from 243 patients with episodic migraine (EM) and 132
patients with chronic daily headache (CDH). We divided the latter gro
up into those with tension-type headache only (CDH Type 1) and those w
ith headaches having migrainous features (CDH Types 2 + 3) and compare
d each with the EM group and all three groups with one another. CDH Ty
pe 1 patients differed from those in the other groups by virtue of gen
der (more often male) and mean age at headache onset (older). The CDH
Types 2 + 3 and EM groups differed only in that the former were more l
ikely to have undergone a brain-imaging study. These data suggest that
CDH Type 1 may represent a distinct headache syndrome, while CDH Type
s 2 + 3 closely resemble episodic migraine.