The vascular "cold patch" is not a prognostic index for headache.

Our previous research has determined that the vascular "cold patch" is a valid diagnostic "marker" and is a persistent constituent of the thermal geography of the external carotid region. It has been suggested by Dalla Volta and Anzola (1988) that the cold patch may be a prognostic index of vascular headache physiology; that is, as headaches improve through the use of vasoactive prophylactic medication, the cold patch would decrease in size or disappear. The purpose of this study is an attempt to replicate these findings. Forty migraine patients were randomly selected, and a thermographic re-examination of the external carotid region (forehead) was conducted. The post-treatment thermogram was then compared to the initial pre-treatment thermogram. Thirty subjects demonstrated an improved condition (IC) and ten subjects a worsened condition (WC). The IC Group exhibited a 73.2% reduction in headache frequency following a mean treatment period of 6.3 months. The WC Group demonstrated a 48.1% increase in headache occurrence at a mean treatment interval of fifteen months. Results demonstrated little thermographic difference between the two conditions. Within the IC Group, 46.7% of subjects exhibited and increase in cold patch size with an improved condition, 40% of cold patches remained stable, 6.7% of cold patches reduced in size, and zero cold patches disappeared with successful treatment. Within the WC Group, 20% of cold patches decreased in size with a worsened condition, 40% increased in size, and 40% remained stable. Chi square analysis determined there was no significant difference in cold patch changes between patients whose headache condition improved or worsened (p less than .70).(ABSTRACT TRUNCATED AT 250 WORDS)