Benzo tolerance withdrawal(body is used to certain amount of benzo and needs more to function..just like tolerance to pain killers) and benzo interdose withdrawl(you can withdraw from xanax 3-4 hours after you take it because the drug is eliminated, leading to rebound anxiety/zaps withdrawal symptoms) for drugs with short half lives(ativan,xanax) can cause brain zaps which can be severe and last a while even after you've been off the drug for months. I believe its due to your brain learning to function again without the synthetic gaba(benzo,alcohol) which causes an increase in electrical activity in your brain. I know that coming off benzo drugs or alcohol cold turkey or too quickly after long term use can lead to seizures, so i would not be suprised if these brain zaps were in the seizure family.
Brain zaps are also common coming off of antidepressants, mood stabilizers, and certain pain meds like ultram(due to it increasing seratonin) but they don't usually last nearly as long as long term tranquilizer use. They can rarely happen goin on to and staying on antidepessants.
As long as the zaps are caused by tranquilizers/benzos, the only way to alleviate them is by raising your dosage(tranquilizers/benzo) or using your last known working dosage where you were stable(tranquilizers/benzo) and hoping you don't get tolerance withdrawal in time. If you ever want to wean off tranquilizers... you have to do it over a period of months to potentially even years depending on your dosage/time on to prevent hardcore withdrawal symptoms. Some people can cold turkey it and be ok.. but many people take months - years to recover this way.
For coming off antidepressants, usualy the worst is over in 2-4 weeks but there can be residual effects a few months later on.
Other central nervous illnesses(such as MS, lyme disease, syphillis, certain viruses, metal poisoning, etc) can cause brain zaps so if you havent been exposed to any of the meds/drugs, it would be advisable to be tested for the above.
In the meantime, to alleviate symptoms temporarily, sitting still or lying down without turning your head fast seems to work. I am not sure of any herbs/suppliments that will work consistently.