Recovery of integrative central nervous function after one hour global cerebro-circulatory arrest in normothermic cat

Functional and metabolic recovery of a female cat is described which survived for 1 year following 1 hour global cerebro-circulatory arrest at normothermia. Ischemia was produced by intrathoracal occlusion of the innominate, the left subclavian and both mammary arteries. Following ischemia the animal was kept under intensive care for 46 h. EEG and evoked potentials began to recover after 3 h following ischemia, and spontaneous respiration returned promptly on the 2nd day when the animal was weaned from the respirator. The neurological deficit score declined from a maximum of 395 immediately after ischemia to 158 during the first week and to 40 within 4 weeks. At this time the animal was slightly ataxic but she was able to walk and to feed and clean herself. One year after ischemia EEG and evoked potentials were normal. Morphological studies and the autoradiographic evaluation of protein biosynthesis revealed an almost normal pattern in cortical structures but there was almost complete atrophy of dorsal hippocampus and striatum leading to enlargement of the ventricular system. These observations demonstrate that despite these lesions the central nervous system is able to recover integrative neurological function after cerebro-circulatory arrest in normothermia of as long as 1 h.