Transient epileptic amnesia in dementia: a treatable unrecognized cause of episodic amnestic wandering.

The authors present two patients with dementia who displayed recurrent transient episodes of amnestic wandering and disorientation characterized by getting lost in familiar environments. At other times these patients did not wander or become disoriented. The inability to recall any information during these episodes, and the marked difference of the episodic amnesia exacerbations from the progressive amnesia characteristic of Alzheimer disease seen in these patients led to their evaluation. These clinical episodes and the bilateral interictal epileptiform electroencephalographic changes found in both patients led to the diagnosis of transient epileptic amnesia, a syndrome that can be diagnostically elusive. These transient amnestic wandering events subsided after treatment with antiepileptic drugs in both patients. The authors suggest that transient wandering of this type may be caused by ictal events or postictal confusional states. This report emphasizes the importance of recognizing transient epileptic amnesia as an easily treatable cause of episodic behavioral abnormalities responsive to antiepileptic therapy, especially in those patients who have a markedly inconsistent pattern of wandering, disorientation in familiar settings, and amnesia exacerbation manifested by no recall of the emotional stress of getting lost or of any information during these episodes. Recognition of this type of behavioral disruption and its proper treatment can lead to improved quality of life for these patients, maintain these patients in their homes and out of chronic care institutions longer, and facilitate the community's and caretaker's interactive roles with the patient.