A case of sleeping and forgetting

• Published in: The Lancet (British edition) 2001-02, Vol.357 (9255), p.524-524
• Main Authors: Corridan, Bryan J, Leung, S N Mary, Jenkins, I Harri
• Format: Article
• Language: English
• Subjects: Aged; Amnesia; Amnesia, Retrograde - diagnosis; Amnesia, Transient Global - diagnosis; Biological and medical sciences; Cardiovascular diseases; Case studies; Diagnosis, Differential; Humans; Male; Medical sciences; Memory; Nervous system involvement in other diseases. Miscellaneous; Neurology; Sleep
• ISSN: 0140-6736; 1474-547X
• DOI: 10.1016/S0140-6736(00)04045-9

The clinical features fulfil Zeman and [Hodges JR.]' diagnostic criteria for Transient Epileptic Amnesia (TEA) (panel).I The term TEA was first used by Kapur in 1990.2 Zeman and colleagues identified 21 reported cases and described a further ten cases.3 TEA is more common in men. The mean age of onset is 60 and half of Zeman's series had a history of heart disease. Attacks resemble TGA in that patients have a combination of anterograde and retrograde amnesia, perplexity, and repeated questioning.1 TEA can be distinguished from TGA by attack frequency. Only 3% of patients with TGA have a recurrence within a year. In contrast patients with TEA have on average three episodes annually.1 The attacks commonly occur on waking. All the patients in Zeman and Hodges' series had at least one episode on waking. TEA can affect verbal and non-verbal memory, whereas in TGA verbal memory is more selectively impaired.4 In TEA the episodes are of shorter duration and the anterograde memory loss is patchy, so patients may recognise their attacks. Patients with TEA may have some permanent impairment of autobiographical memories, which Zeman and Hodges suggest may be partially due to ictal activity in mesial temporal lobes disrupting memory consolidation in sleep.1