The disappearance of the "cold patch" in recovered migraine patients: thermographic findings.

In a previous paper we suggested that the vascular cold patch may be a useful prognostic index to followup migraine patients. Considerable criticism against our contention has been raised by Swerdlow and Dieter (Headache 29:562-568, 1989, ref. 1), who claim that the cold patch constitutes a "fixed geography" of the vasculature of migraine patients. In the present paper we replicate and extend our previous findings reporting the results of facial thermography in a sample of 246 consecutive migraine patients. Of these the 206 exhibiting a typical cold patch or a significant asymmetry in the forehead thermal dissipation were admitted to prophylactic treatment (beta blocker or calcium channel blocker). The thermography was performed at entry in the study and after six months of active treatment. The clinical outcome was compared to the thermographic findings. The patients were subdivided in three classes on the basis of the clinical outcome. Among the 136 patients who experienced complete or substantial relief from headache the cold patch disappeared or markedly improved in 85% of the cases. In the 46 patients with partial relief the thermogram showed an improved pattern in 48% of cases, most of the time of smaller extent than in the previous class. In 24 patients we observed no clinical improvement. Among these the thermogram remained unchanged in 85% of cases. Taken together these findings corroborate our previous suggestion that thermography is useful to monitor the clinical course of the disease. One additional suggestion from the present data is that thermography closely parallels the clinical course so as to represent a useful criterion for the decision of discontinuing the therapy.