Birds are not immune from having seizures. A seizure is caused by a paroxysmal, uncontrolled transient electrical discharge in the brain.
One common cause is hypocalcemia . Your vet needs to get a blood chemistry, but be forewarned, these are not absolute. A normal range result doesn't mean this isn't the problem, it may just mean that another blood chem. needs to be run at a different time of day (even the same day).
Increasing calcium levels is rarely a bad idea, so be sure plenty of fresh cuttlebone is in the cage. Regularly scrape the cuttlebone to reveal a fresh under layer and replace as necessary with new. Even if you don't think your bird is using it, be sure it's there. I keep it near the fresh food dish so they have an option for wiping their beaks off after eating some oatmeal or bean medley (they love it, but look like toddlers with goo all over their faces afterward).
Also, increasing the calcium rich foods they eat is helpful, from giving them a sip of calcium enriched orange juice (all natural, organic please) once a day to plenty of dark green, leafy vegetables and cruciferous options like broccoli and Brussels spouts are healthy. Cottage cheese, yogurt, almonds or even a regular Tums are more choices.
Some recommendations are to put calcium supplements in water; however, most birds won't drink it and the health threat of going without water is just another problem added to one you have already. I wouldn't put anything in my birds' water. It's just not worth the risk.
With this said, it's important to note that a calcium deficiency is, by itself, not likely to be the only causation. Something is causing the calcium deficiency, usually problems with their uropygial gland, parathyroid and more.
In order to fully utilize the calcium they get in their healthy diet, a bird needs regular exposure to ultraviolet light (sun light), just like we humans do.
Some birds will have squamous metaplasia of the uropygial gland (it doesn't function properly) and it contributes to hypovitaminosis A. In this case a beta carotene treatment may be prudent. A regular low dose beta-carotene capsule cut open and squeezed onto a bird treat or if your bird is cooperative, directly into their mouth, is converted to vitamin A without building up in their system.
What I can't stress enough though is that self-medicating a bird is never, ever a good idea and can delay proper treatment if it's something else.
Also to be considered and ruled out are: central nervous system diseases such as a brain tumor or infection, head trauma, hyperthermia, liver disease, metabolic disturbances (hypocalcemia, hyperglycemia) and toxicity from lead, zinc, aflatoxins and certain insecticides. If no cause is found after a thorough evaluation, the bird is said to have idiopathic epilepsy.Linda Pesek, DVM/Avian Board Certified is quoted: "A bird that seizures should have a thorough physical examination, radiographs, hematology and blood chemistry. A complete blood count will reveal whether anemia, inflammation or infection is present. Blood chemistries provide an indication of liver and kidney function and the electrolyte status of the patient. A radiograph may demonstrate the presence of metallic densities in the gastrointestinal tract. Although one cannot rule out the presence of lead or zinc toxicity if no metallic densities are present, finding them leads support to the possibility of heavy metal poisoning as the cause of the seizures. Definitive diagnosis is based upon the presence of toxic levels of lead and zinc in the blood."
In addition to a baseline complete blood count and chemistry, certain infectious diseases such as chlamydia, polyoma and proventricular dilitation should be ruled out if possible
I can't stress enough that a professional evaluation is necessary - and it must be with an avian vet or other well experienced vet who sees birds.
So even though she seems fine now - don't delay.
Certified Avian Specialist
Cert. Avian Specialist; Int. Assoc.Animal Behavior Consult; Pet Ind. Joint Advisory Council; author