Convulsions
Visual Distortion — Any impairment in vision, including “tunnel” vision.
Ears — Any changes in normal hearing function, especially a “ringing” sensation.
Nausea — This may vary in severity and be intermittent.
Twitchiness — Muscle spasms of any kind, especially in facial muscles.
Irritability — Uncharacteristic personality changes, anxiety and confusion (as mentioned earlier, this is also a sign).
Dizziness — Vertigo or disorientation.