Cortical and brainstem patterns of damage - as found in monkeys
		Palmer and Rossdale compared their findings with the two patterns of damage described by Myers in 1972 seen in monkeys subjected to hypoxia and or asphyxia shortly before or after birth.  Myers subjected monkeys to partial hypoxia late in gestation, which resulted in damage of the cerebral cortex similar to that seen in human cases of cerebral palsy.  On the other hand, when he inflicted catastrophic total asphyxia at birth for several minutes, damage was restricted to the brainstem.  Palmer and Rossdale found brainstem damage in foals who suffered apnea at birth, including lesions of the inferior colliculi as had been the case in monkeys subjected to asphyxia.

In 1976 and 1976 Palmer and Rossdale reported neuropathological changes
found in 18 foals that had exhibited signs of the "convulsive foal syndrome."  
A spectrum of changes in the brain were observed, including ischemic
necrosis within the cerebral cortex in nine of the foals, with involvement of the
diencephalon and brainstem in three of these.  Hemorrhagic damage of the
cerebrum, and sometimes the brainstem and cerebellum, was observed in
the other nine foals.