The interpretation of non-organic memory symptoms in younger people. Dr Jeremy Isaacs Consultant Neurologist St George s Hospital

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1 The interpretation of non-organic memory symptoms in younger people Dr Jeremy Isaacs Consultant Neurologist St George s Hospital

2 I m worried about my memory Awareness and fear of dementia in the population is increasing Public health campaigns have not distinguished between benign and non-benign memory symptoms This is generating a lot of worried well people

3 Dementia is rare in younger people Incidence of dementia in age group 11.5 cases per 100,000 person-years Alzheimer s disease 4.2 Frontotemporal dementia 3.5 Huntington s disease 0.8 Extrapolated across England and Wales 460 new cases of FTD and 550 new cases of Alzheimer s each year Mercy et al, Neurology 2008

4 Functional cognitive disorders Subjective cognitive symptoms in the absence of brain pathology Commonest cause of cognitive symptoms in people aged <65 Has distinctive features that allow a positive diagnosis to be made Courtesy of Dan Blackburn

5 Epidemiology of functional cognitive symptoms Cognitive Symptom Frequency Reported in Community Controls: n=223, mean age 30 Forgets recent telephone conversation 9% Forgets why they entered room 27% Forget yesterday s breakfast 27% Forgets where car was parked 32% Loses car keys 31% Forgets where they went today 5% Forgets appointment dates 20% Loses items around house 17% Concentration difficulty 14% McCaffrey RJ, Bauer L, Palav AA, O Bryant S (2006). Practitioner s guide to symptom base rates in the general population, Springer Science, & Business Media.

6 College Students: n=620, age range Memory Gaps 10% Speech problems 17% Word finding lapses 27% Unrecalled behaviour 9% McCaffrey RJ, Bauer L, Palav AA, O Bryant S (2006). Practitioner s guide to symptom base rates in the general population, Springer Science, & Business Media.

7 Types of functional cognitive complaint Lapses of attention or concentration I went upstairs/into a room/opened the fridge door and forgot why These experiences are not due to memory loss They happen because we have evolved not to encode everything that s in our short-term memory Minor memory or word retrieval difficulties I can t remember people s names I couldn t think of the word for They happen because of physiological inefficiencies in word retrieval

8 In FCD, attention is shifted towards physiological cognitive lapses Cognitive hypervigilance This uses up attentional reserve Making people more distractible Less likely to encode information in short term memory Attentional reserve also depleted by introceptive focus on pain, fatigue, other persistent physical symptoms, emotional distress Followed by a catastrophic interpretation i.e. that something must be wrong

9 Hypothetical model of FMD Metternich, J Psychosom Res. 66(2009) [adapted from Behav Res Ther 28 (1990) , J Psychosom Res 36 (1992) ].

10 Classification of functional cognitive disorder 1. Isolated functional cognitive disorder - Including following specific triggers e.g. mild TBI, chemotherapy - With or without dementia-related health anxiety 2. Functional cognitive symptoms associated with mood disorder 3. FCD in association with another functional disorder e.g. chronic fatigue syndrome, fibromyalgia Adapted from Stone et al. Journal of Alzheimer s Disease 48 (2015) S5 S17

11 Approach to the functional cognitive patient As in any functional disorder, hallmark is incongruity between the patient s subjective experience of bodily function and what is objectively demonstrable Look for inconsistencies between subjective burden of symptoms and objective everyday functioning Patient holding down high powered job or complex family commitments despite high burden of cognitive symptoms Patient reporting poor memory who describes memory lapses in exquisite detail Patient is convinced of a problem but partner and others haven t expressed concern Determine whether the predominant issue is the consequence of cognitive lapses or the patient s emotional response to them

12 Predisposing Precipitating Perpetuating Perfectionist expectations of cognitive performance Stressful life event Depression Subjectively impaired metamemory Physical illness including mild TBI & chemotherapy Hypervigilance to cognitive lapses Early life trauma Major psychiatric illness Catastrophic interpretation of cognitive lapses Other functional disorders e.g. CFS, fibromyalgia Relative developing dementia Specific dementia-related health anxiety Chronic pain Ongoing stress Tendency to dissociate Health anxiety Reduced attentional reserve

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14 Examination Brief cognitive instruments have limited value in younger patients with mild cognitive symptoms where the differential diagnosis is FCD vs a prodromal dementia Too insensitive to pick up subtle impairments, especially in well educated subjects (false negative) Not designed to detect non-ad dementias (false negative) Many patients with FCD will lose marks due to poor effort (false positive)

15 Better to observe patient s speech for features of normal cognition Richly detailed history with multiple examples of cognitive lapses History in which events are precisely located in time Patient s ability to reference an earlier part of the consultation Absence of word finding pauses or other speech errors No need for investigations if confident clinical diagnosis made Delays signposting patients to appropriate intervention

16 Treatment Explanation and reassurance Introduce concept of functional cognitive symptoms Almost always accepted by patients Provide feedback on how their ability to give a detailed history is a sign of normal memory function e.g. your memory works fine when you aren t focussing on it In mild cases normalisation of symptoms might be sufficient If any suggestion of depression, discuss treatment options with patient Encourage graded return to normal utilisation of memory CBT targeted to cognitive symptoms possible in experienced hands, but unproven

17 Summary Subjective cognitive symptoms are very common in the population People who present are different from the background population They have specific predisposing, precipitating and perpetuating characteristics A positive diagnosis should be possible based on patient profile and symptoms, including incongruities, exactly as in other FNDs Likely that offering a sympathetic explanation and reassurance, treating depression and targeted CBT will help Patients who are off work need urgent intervention Further research on treatment is needed

18 Thank you