Clinical signs of PEM are variable depending on the area of the cerebral cortex affected and may include:
head pressing,
dullness,
opisthotonos, : a condition of spasm of the muscles of the back, causing the head and lower limbs to bend backward and the trunk to arch forward
central blindness,
anorexia, : loss of appetite especially when prolonged
muscle tremors,
teeth grinding,
trismus,
salivation, drooling,
convulsions,
nystagmus, : involuntary usually rapid movement of the eyeballs (as from side to side) occurring normally with dizziness during and after bodily rotation or abnormally following head injury or as a symptom of disease
clonic convulsions, : a rapid succession of alternating contractions and partial relaxations of a muscle occurring in some nervous diseases
recumbency : the state of leaning, resting, or reclining;
[2] Early administration of thiamine may be curative, but if the lesion is more advanced, then surviving animals may remain partially blind and mentally dull.