Clinical features of episodic migraine and transformed migraine: a comparative study.

Transformed migraine (TM) is one of the most frequent types of chronic daily headache. Eighty patients: 40 with episodic migraine (EM) and 40 with TM with ages ranging from 18 to 60 years old were studied. Females were the majority. At first examination, the mean age was similar in both groups. The initial age of migraine attacks was significantly smaller in the TM group. Time history of episodic attacks was similar in both groups. In the EM group, the headache was predominantly located on only one side of the head; whereas in the TM group, on more than one side. There was variation in the character of pain and intensity in the TM group. Nocturnal awakening with headache, aura and family history did not show significant association with EM or TM. The TM was distinguished from the EM in relation to the frequency, location and pain intensity of the headache. Patients with early migraine headache onset may exhibit a further risk of developing TM.