Table 3.

Main features of transient epileptic amnesia and Alzheimer’s disease-associated epilepsy

	Transient epileptic amnesia	Alzheimer’s disease-associated epilepsy
Mean age at onset of seizures	62–69 years	62–74 years
Sex	More common in men	Equally common in men and women
Seizure semiology	Amnestic spells on waking (100%), olfactory hallucinations (about 42%), automatisms (about 36%), and generalised tonic-clonic seizures (about 4%)	Automatisms (about 31%), sensory phenomena or unexplained emotions (about 22%), speech or behavioural arrest (13–39%), déjà vu or jamais vu (5–8%), amnestic spells (4–54%), staring spells (about 3%), and generalised tonic-clonic seizures (15–40%)
Interictal cognitive complaints	Autobiographical memory loss, accelerated forgetting over days to weeks, and topographical memory loss	Short-term memory loss, word-finding difficulty, difficulty with multitasking and calculations, and visuospatial impairments
Neuropsychological features	Normal or near-normal performance on standardised neuropsychological tests; impairments in recall of verbal and visual information at extended delays (>30 min); loss of autobiographical memories for events extending decades before onset of seizures.	Impairments in multiple cognitive domains on standardised neuropsychological tests including learning and recall of verbal and visual information, executive function, language abilities, and visuospatial function.
EEG epileptiform foci	Temporal or frontotemporal	Temporal, frontotemporal, or frontal
Brain MRI	Normal (group studies suggest subtle atrophy in limbic structures)	Grey matter atrophy in medial temporal lobes or posterior cortical regions
Alzheimer’s disease biomarkers*	Probably negative (not systematically studied)	Positive
Response of seizures to antiepileptic drugs	Good	Good

Data are from multiple sources.^{2–4,21,78,79} EEG=electroencephalography.

^*PET measures of brain amyloid β deposition and cerebrospinal fluid measures of amyloid β, tau, and phosphorylated tau. These biomarkers are less accurate in assessing the likelihood of Alzheimer’s disease in people over 80 years old.⁸⁰