NICE, dense amnesia and the man who forgot he’d made love with his wifeSimon Curtis - 11 Jul, 2019
‘Yesterday my wife and I made love and I can’t remember anything about it’ is one of the more unusual openings to a consultation I’ve had. This case was over 20 years ago, I was a newly qualified GP, but I’ve never forgotten it. Using my recently acquired consulting skills I naturally followed with an open question: ‘so, do tell me more about it’. My frustrated and now irritated patient then pointed out to me that that was the whole point, he couldn’t remember. But his wife could, and she proved to be a good witness.
Having woken feeling fine, which he could remember, he then had 4 or 5 hours during which he could remember nothing and during which the said love making, and several other quotidian activities, had occurred. During this period once he was reminded by his wife what had recently happened he became increasingly anxious and agitated as he realised he could not remember it or indeed retain any new information leading to him to repetitively question his poor wife. After 6 hours or so everything came back to normal and he could retain new information, but those hours remained lost in his recall.
Exploring his ideas, concerns and expectations further (remember, I was newly qualified…) he and his wife were worried that he may have had an orgasmic stroke as apparently the said act was, according to his wife, ‘quite vigorous’ (‘and I can’t remember!’ moaned my patient). This then struck me as plausible that he may have had a vascular event, and he had a couple of risk factors, so I referred him urgently. He was scanned, no cause was found and he was discharged as my first case of ‘transient global amnesia’. I have seen a good few cases since, but once seen (or experienced!) TGA is rarely forgotten.
Like a lot of sudden new neurological symptoms TGA or dense amnesia creates a conundrum for us. We don’t want to over refer and yet, increasingly so in a time of defensive medicine, we don’t want to miss anything. So should we refer acutely or should we reassure?
To help answer this, and many other questions for other new neurological symptoms (from patients with blackouts to anosmia to vertigo etc), NICE have recently published a fascinating new guideline advising about Suspected neurological conditions, recognition and referral 2019 NG127. Rather confusingly, they call TGA ‘dense amnesia’ but they reassure us that it is benign and that referral is NOT necessary if it is a single episode that lasts less than 8 hours, there is complete recovery and there are no features suggestive of an epileptic seizure. If it happens recurrently, it could be transient epileptic amnesia and then does need referral. NICE are to be congratulated on producing such a useful guideline for primary care, but it is long (74 pages!) and complex. We shall be covering it for you, with illustrative cases and keep it simple summaries, on our upcoming Autumn courses.
So, what causes TGA or dense amnesia? That we don’t know, but we can reassure our patients that it is benign and the risk of recurrence is low. It can be triggered by precipitating events including sex, swimming in cold water or acute stress. I can imagine my patient would say he’d be happy to avoid two of those…