Do not take more than 2 Ampyra tablets in a 24-hour period. Do not use a tablet that has been broken or crushed. A broken tablet can release too much of the drug at one time. This can increase your risk of having a seizure. Stop taking Ampyra and call your doctor at once if you a seizure, pain or burning when you urinate, problems with your balance, numbness or tingly feeling, or a relapse of your MS symptoms.

Does any of this sound like your experiences? If so, may need to have a chat with the doc.