The effects of cerebral haemodynamics on the progression of cold-induced oedema.

A cold-injury lesion was made on the brain of 14 of 21 adult mongrel cats. Cerebral blood flow (CBF) and cerebral blood volume (CBV) were observed in both groups during the next 6 to 9 hours using a laser Doppler flow meter. Intracranial pressure (ICP), water contents, and blood pressure were also measured. Hyperemia frequently reached a peak early in the test period in the gray matter and somewhat later in the white matter. In a few cases, hyperemia was observed to occur late in the test period in the gray matter and even later in the white matter. The least frequent pattern was a continuous decrease of CBF and CBV in gray matter over time and of CBF in white matter. Intracranial pressure rose rapidly and correlated well with the early hyperemia. The water content was significantly increased in the white matter. However, the difference in the rate of the increment of the water content was not significant from 7-9 hours after injury. Hyperemia seems to cause the severe impairment of the microcirculation during oedema formation induced by cold injury. A time difference of hyperemia was detected in the gray matter and the white matter.