Objective: Transient epileptic amnesia (TEA) is a recently individualized syndrome occurring in adult patients that includes epileptic seizures with amnestic features and interictal memory disturbances.
Methods: We investigated the clinical, neuropsychological, and 18F-FDG positron emission tomography (18F-FDG-PET) features of 30 consecutive cases of TEA in our center.
Results: The mean age of onset of amnestic seizures was 59 years. Pure acute amnesia was the only epileptic manifestation in 17% of cases. Interictal electroencephalography (EEG) abnormalities were present in 57% on awake recording and in most patients in whom sleep EEG was performed (96%). Nine of 30 patients showed anterograde memory deficit and six of 30 exhibited mild executive functioning impairment. On the autobiographical memory interview (AMI), patients showed a significant deficit for the recent period of the episodic subscale. Outcome under treatment was favorable in the majority of cases. A significant improvement was noted on recollection of autobiographical memory. 18F-FDG-PET (22 cases) showed positive correlations between left mesial temporal metabolism levels and anterograde and retrograde memory scores.
Significance: TEA is an emerging epileptic syndrome that likely remains misidentified and misdiagnosed. Neurometabolic data support a dysfunction of a hippocampal-neocortical network sustaining episodic memory.
Keywords: Accelerated forgetting; Amnesia; EEG; Epilepsy; Episodic memory; FDG-PET.
Wiley Periodicals, Inc. © 2014 International League Against Epilepsy.