While I have no confidence that Russians had any damn thing to do with his mother's death, I also am utterly confident anybody could have.
It has been proven that EMF (Electro magnetic frequency) radiation can activate neurons, and this was known decades ago. There were concerns HAARP was being used to make people hear and see things.
Manufactured hallucinations are probably quite real, perhaps relatively trivial to create now.
Lord only knows what they can do to an unbalanced mind.
Thanks!