Sudden memory loss is considered to be caused by a neurological disorder in the brain, most often considered to be a transient ischemic attack. If the lesion is in the temporal lobe, frontal lobe or hippocampus, the patient may experience memory loss, but the memory will recover quickly after a period of time. If the patient’s sudden memory loss does not recover for a long time, it is considered to be caused by cerebral infarction, and the patient must promptly consult a hospital for magnetic resonance brain imaging to clarify. For example, many patients with epilepsy will experience loss of consciousness when they have a seizure, and after they are conscious, they will have no memory of what happened during the seizure, so an EEG can be done to clarify this.