Effect of acetazolamide on cerebral blood flow and tympanic temperature in healthy subjects and patients with subacute subarachnoid haemorrhage.

The influence of the increased cerebral blood flow (CBF) induced by acetazolamide on tympanic temperature (Tty) was examined in three healthy male volunteers and in five patients with subacute subarachnoid haemorrhage (SAH). The CBF was estimated by means of stable xenon-enhanced computed tomography before and after the administration of acetazolamide. The Tty was recorded continuously in both ears using thermistor thermometers. In all subjects, CBF increased ranging from 11% to 108% after acetazolamide administration. In all the healthy subjects and in two patients with mild SAH, Tty was higher than the oesophageal temperature (Toes) and Tty decreased bilaterally, ranging from 0.07 to 0.35 degree C as CBF increased. Three patients with severe SAH were febrile, their Toes exceeding Tty and their Tty rose by 0.30 to 0.53 degree C with increased CBF. These observations suggest that Tty follows brain temperature which changes with an increase in CBF in euthermic subjects as well as in febrile subjects.