Oh, goodness, ! That must have been scary for you both! Seizures are not very common with MS, but they do happen. If you haven't done so already, make sure your husband checks in with his doctor about this. Some seizures can be a "one off" and a person may never experience another one. But, sometimes, a person will deal with more seizures following the initial event. A couple of our contributors here deal with MS related seizures. Here's one of their experiences with seizures -- https://multiplesclerosis.net/living-with-ms/manage-fairly-uncommon-partial-complex-seizures.