Hi.
Seizures are indeed a symptom that is associated with withdrawal of the drug.
Taken from the consumer information for zolpidem (Ambien):
"Do not stop taking this medication suddenly without first talking to your doctor. You may need to use less and less before you stop the medication completely.
Withdrawal symptoms include behavior changes, stomach pain, muscle cramps, nausea, vomiting, sweating, anxiety, panic, tremors, and seizure (convulsions). "
You should consult a physician to assess your withdrawal symptoms.
Hope this information helps.
I was also taking ambien, and within a few days of stopping abruptly I had a grand mal sezure. I should have consulted my doctor, but after wrecking my car and not remembering getting out of bed I decided it was time to stop. I'm not sure any amount of sleep is worth the side effects of this drug.