I really don't know the answer about "poisonous-ness" of palm tree spikes, but we have date palms in our back yard and when I get "bit" by one it starts being painful and stiff after about an hour....
No, I do not believe palm trees are poisonous to cats. Here is a list of plants that are poisonous to cats Almond (Pits of) Aloe Vera Alocasia Amaryllis Apple (seeds) Apple Leaf Croton Apricot (Pits...