Cerebral Vascular Blood Flow Changes During ‘Brain Freeze’

Abstract

‘Brain freeze’ commonly occurs when ice cold food or liquid is rapidly consumed. It's mechanism remains unclear, however rapid cooling of the brain through the upper palate may cause local cerebral blood flow changes. The purpose of this study was to examine whether ‘brain freeze’ induces the hypothesized cerebrovascular changes.Using transcranial Doppler, we evaluated cerebral blood flow velocity (CBFV) in the middle (MCA) and anterior (ACA) cerebral arteries in 13 healthy adults while consuming ice and ambient water. Subjects drank ice water through a straw against the palate until pain developed. CBFV, heart rate, and blood pressure were analyzed, before pain, during pain and after pain.Consumption of ice water produced a tendency towards increased cerebral flow velocity in the ACA (P=0.078) but not the MCA (P=0.24). Ice water also resulted in greater cerebrovascular resistance during the experimentally induced “brain freeze” when compared to following ambient water consumption.Our results support a vascular mechanism for brain freeze. Ice water consumption resulted in a significantly greater cerebrovascular resistance as compared to that during ambient water consumption. However, the fact that cerebral flow increased during pain along with increases in blood pressure may suggest autoregulation was not as effective. Supported by NASA and NIH.