I am having vertiginous seizures. How dangerous are these and can they be treated?

Compound question. Seizures are inherently potentially dangerous as a source of physical injury to self and others (especially if driving). Also seizures beget seizures. The more you have, the more you get. Prolonged or frequent seizures can and do cause permanent brain damage. At least 60% of seizures can be completely controlled medically (note, i didn't say "cure").