Neurologic Deficit and Cerebral ATP Depletion after Temporary Focal Ischemia in Cats

Abstract

Focal ischemia was induced in 23 cats by occluding the left middle cerebral artery for 2 h. The animals were then divided into groups for unforced reperfusion of variable duration ranging from 2 to 48 h. Neurological ratings were obtained during both ischemia and reperfusion. Following planned sacrifice the regional ATP content was assessed by means of a bioluminescence method showing spatial distribution and degree of ATP depletion. All the animals developed a neurologic deficit, with a median of 6 points on a disability scale of 0–10. After reopening of the middle cerebral artery, neurologic recovery was quite variable depending on the initial neurologic deficit (partial φ = 0.67, p1 < 0.05): Animals with mild initial functional impairment improved and those with severe neurologic disturbances either died early or developed a more severe neurologic deficit, irrespective of the duration of reperfusion. The degree of ATP depletion and the amount of brain tissue involved exhibited a significant correlation with the neurological outcome (τ = 0.50, p1 < 0.05), but they were even more closely related to the initial neurologic deficit (partial φ = 1.00, p1 < 0.001), suggesting an early definitive manifestation of deficiencies in regional energy metabolism.