Good Morning All,
Symptoms described as "brain zaps", "brain shocks," "brain shivers" or "head shocks", are a withdrawal symptom experienced during discontinuation (or reduction of dose) of antidepressant drugs. The symptoms are widely variable in description and of unknown etiology. Common descriptions include dizziness, electric shock-like sensations, sweating, nausea, insomnia, tremor, confusion, and vertigo.
Not everyone experiences brain zaps. I hope this helps.