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• Reply from Pennington et al.
  C Pennington
  Published on: 14 April 2016
• Re: Pennington et al. Functional cognitive disorder: what is it and what to do about it?
  Jan A Coebergh
  Published on: 14 April 2016
• A case of functional cognitive disorder with acute onset?
  Rachel A Cichosz
  Published on: 14 April 2016

• Published on: 14 April 2016

  Reply from Pennington et al.

  • C Pennington
  • Other Contributors:
    • M Newson, E Coulthard

  We welcome debate around this emerging condition. We all recognise a situation when as clinicians we have had a strong feeling that a patient has a functional complaint from early on in the consultation. However, the differential diagnosis for Functional Cognitive Disorder is neurodegenerative dementia which itself affects behaviour and personality and could, therefore, influence many of the cues clinicians pick up on wh...

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  We welcome debate around this emerging condition. We all recognise a situation when as clinicians we have had a strong feeling that a patient has a functional complaint from early on in the consultation. However, the differential diagnosis for Functional Cognitive Disorder is neurodegenerative dementia which itself affects behaviour and personality and could, therefore, influence many of the cues clinicians pick up on when "divining" a functional diagnosis. Anecdotally, we have seen patients in our clinic diagnosed with a functional disorder at other centres whom we have subsequently discovered to have definite neurodegenerative disease. As an example, we were referred a patient thought to have a psychiatric disorder and functional left leg movements. After a detailed assessment including CSF biomarkers and SPECT scanning, we suspected organic disease. His positive C9orf72 genetics have recently demonstrated he suffers from a genetic form of Frontotemporal dementia and we believe that this altered his behaviour such that he manifested a functional syndrome at the start. Preceding medical events such as general anaesthesia or chemotherapy can be triggers for health anxiety or FCD, but could also be a source of cognitive symptoms. General anaesthesia (particularly if performed for cardiac indications) is a risk factor for hypoxic or ischaemic brain damage (which if focal can present with isolated cognitive deficits). Chemotherapy agents can cause neurological complications (e.g. methotrexate encephalopathy); their use also implies a history of malignancy with consequent risk of tumour recurrence and direct or indirect neurological complications. Establishing the aetiology of cognitive complaints is the key challenge in the memory or general neurology clinic. Large-scale research studies suggest there is a continuum between Subjective Cognitive Impairment (where individuals report cognitive symptoms but perform normally on testing), MCI and dementia2. Given treatments may be effective only in the earliest stages, identifying prodromal dementia will in the future be increasingly important. Distinguishing incipient dementia at the Mild Cognitive Impairment (MCI) phase from Functional Cognitive Disorder (FCD) can be difficult, but is of vital importance to ensure patients receive appropriate prognostic information including reassurance where necessary and are entered into clinical trials where appropriate. This distinction becomes particularly tricky in high-functioning individuals, and those with co-morbid psychiatric conditions. The clinical history is very useful, and conversational analysis has been successfully used to differentiate dementia from FCD1. However we would counsel against solely using the clinical history to distinguish FCD from incipient dementia at the MCI phase. We know that anxiety, depression and abnormal behaviour may occur in early dementia all of which might confound use of a clinical history to differentiate incipient dementia from FCD. Neuropsychology assessments are very useful in this context- they can reveal patterns of deficits that are not consistent with organic pathology, deficits out of keeping with FCD, or highlight significant psychiatric symptoms warranting referral to psychiatry or psychology services. Neurologists are often not trained in identifying psychiatric disorders, therefore a structured neuropsychology assessment including questionnaires looking for symptoms of depression or anxiety can often be very helpful. The authors would regard neuroimaging as an essential part of the assessment, as recommended by NICE3. Even a patient with a 'classic' FCD history may be harbouring structural brain pathology. To give a clinical example, a 56 year old man presented to our general neurology clinic with intermittent word finding difficulties during conversations and when typing. He had a history of anxiety disorder, and his language appeared normal during the consultation and on formal assessment. Neurological examination was normal, and a functional cause was suspected. However on MR imaging a large glioblastoma multiforme was found. Not performing neuroimaging risks missing individuals with a strategic infarct, malignancy or other structural pathology. Whilst such cases are not common, missing such a diagnosis would have very serious consequences for the patient. The authors agree that investigations such as SPECT, CSF biomarkers and autoantibodies should be used selectively, but these can be helpful in difficult cases. We plan to explore further the additive clinical value of each of these tests. Discovering the aetiology of cognitive symptoms often requires us to operate at the limits of current knowledge about how the brain guides behaviour. We do not believe we are at the point where we can always offer certainty to a patient. However, we find it possible to reassure patients effectively even when we represent this uncertainty to them. If we suspect functional cognitive disorder, we introduce the concept at the first consultation and offer reassurance saying we will do further tests and follow up to rule out rarities. We find this is actually quite effective as a means of reassurance, perhaps more so than being entirely dogmatic that there cannot be organic pathology as most patients will know it is more or less impossible to prove a negative in neurology. Overall we feel that whilst we might strongly suspect FCD clinically at the first consultation, it is unwise in almost all cases to make a firm diagnosis of FCD without appropriate investigations. Even after diagnosis and initial management of FCD, a period of clinical follow up can be informative. It is only such follow up that has allowed us to begin to understand critical components of FCD and to summarise clinical features of the condition.

  References 1. Elsey, C., Drew, P., Jones, D., Blackburn, D., Wakefield, S., Harkness, K., Venneri, A. & Reuber, M. Towards diagnostic conversational profiles of patients presenting with dementia or functional memory disorders to memory clinics. Patient Educ. Couns. pii: S0738, (2015). 2. Garcia-ptacek, S., Cavallin, L., Kramberger, M. G., Winblad, B., Jelic, V. & Eriksdotter, M. Subjective Cognitive Impairment Subjects in Our Clinical Practice. 419-430 (2014). doi:10.1159/000366270 3. NICE. Dementia diagnosis and assessment. (2015).

  Conflict of Interest:

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  Conflict of Interest:
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• Published on: 14 April 2016

  Re: Pennington et al. Functional cognitive disorder: what is it and what to do about it?

  • Jan A Coebergh
  • Other Contributors:
    • Biba R Stanton, Jeremy D Isaacs

  Pennington and colleagues review of Functional Cognitive Disorder (FCD) [1] is very welcome to guide practice in a complex condition that is presenting increasingly to general and cognitive neurology clinics. However, in our view Pennington's presumption towards specialist assessment, investigation and surveillance is unnecessary and misses an opportunity to provide patients with a prompt diagnosis, explanation and reas...

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  Pennington and colleagues review of Functional Cognitive Disorder (FCD) [1] is very welcome to guide practice in a complex condition that is presenting increasingly to general and cognitive neurology clinics. However, in our view Pennington's presumption towards specialist assessment, investigation and surveillance is unnecessary and misses an opportunity to provide patients with a prompt diagnosis, explanation and reassurance and immediate treatment for the FCD and/or significant relevant co-morbidities e.g. depression, chronic fatigue syndrome (CFS). In particular, we cannot agree with Pennington's comment that "Functional cognitive disorder should be diagnosed only after excluding other causes of cognitive decline as far as possible". We believe that clinicians should aim to make a positive "rule in" diagnosis of FCD, exactly as proposed for other functional disorders [2] and that this can be done in the context of the general neurology clinic. Pennington et al rightly point out features in the history that suggest FCD but in our view they underestimate their significant diagnostic value. Additional positive features for FCD in our experience are a high number of presenting symptoms, the patient's emotional response to the symptoms being more distressing than the actual consequences of any cognitive lapses, co-morbid mood disorders, chronic pain or fatigue and recent relevant life events including physical illnesses such as mild traumatic brain injury, anesthesia or chemotherapy exposure. Brief cognitive instruments (such as MoCA, ACE) are of limited value in this context and have an opportunity cost in a 30 minute general neurology consultation. Instead we suggest listening for particular features in the patient's spontaneous speech that point towards FCD. A richly detailed history in which multiple examples of cognitive lapses are described, and in which events are precisely located in time, the patient's ability to reference an earlier part of the consultation [4], and normal expressive language (e.g. the absence of word finding pauses) are all evidence of normal cognitive function. These can be fed back to the patient to help explain the diagnosis, in the same way that a positive Hoover's sign can be explained to a patient with functional lower limb weakness. We argue that most patients with suspected FCD do not need investigations such as brain imaging or neuropsychology. These are much more likely to produce false positives with attendant iatrogenic harm than to shed any light on the diagnosis, particularly in younger patients where the pre- test probability of dementia is extremely low. The authors write that "Cerebral atrophy that is out of keeping for the patient's age ... should prompt further investigations". We would regard lower than expected brain volume as a non-specific finding in a patient with typical FCD symptoms. The temptation to perform further tests to clarify non-specific findings from a previous test demonstrates the perils of embarking on low yield investigations in the first place. Tests for anti-VGKC and NMDA receptor antibodies should be reserved for patients presenting with the clinical syndromes associated with these antibodies, which are readily differentiated from FCD on the basis of the clinical history. We believe that routine neuropsychological assessment for the diagnosis of FCD is clinically unnecessary, not cost-effective and potentially misleading. For example, a neuropsychology report stating that "early neurodegeneration cannot be ruled out" in a case where the clinician strongly suspects FCD may reduce patients' confidence in the diagnosis. We would virtually never consider amyloid positron emission tomography or cerebrospinal fluid biomarkers appropriate for patients with suspected FCD (although they may have a role in rare cases in which a diagnosis of Alzheimer's disease needs to be changed to FCD and this is not initially accepted by patients, family and other healthcare professionals[5]). These tests are abnormal only in Alzheimer's disease so cannot "rule out" dementia in any case. We welcome Pennington's comments about the need to develop treatments for FCD. One of us (JAC) often recommends two books to patients that beautifully illustrate the idiosyncrasies of normal memory; Forgetting by Daaisma and Moonwalking with Einstein by Joshua Foer. For patients with mild FCD, normalising their symptoms e.g. by explaining how we (the neurologist) make many of the same mistakes can be helpful. An emerging nosology can help practitioners select an individualised explanatory model and prioritise treatment i.e. (1) FCD in isolation, with or without dementia-related health anxiety, (2) FCD in the context of a psychiatric co-morbidity (most typically depression) and (3) FCD as a feature of another functional disorder e.g. CFS, fibromyalgia (adapted from [6]). The stability of functional neurological diagnoses is well demonstrated and the same likely applies to FCD, as Pennington and colleagues point out. We therefore disagree with the suggestion that it is necessary to follow patients up to ensure that their cognitive function remains stable. Follow-up might of course be offered for other reasons e.g. where the clinician needs more time to explain the diagnosis. In summary, while welcoming Pennington and colleagues important contribution to this emerging area of neurological practice, we urge general neurologists to have confidence in making a positive diagnosis of FCD, particularly in younger patients. We believe that unnecessary specialist referral, investigation and surveillance of patients with FCD risks delaying treatment and potentially incorrect diagnoses of pre- dementia (e.g. MCI) or dementia itself.

  References 1. Pennington C, Newson M, Hayre A, et al. Functional cognitive disorder: what is it and what to do about it? Pract Neurol 2015;15:436-444 2. Stone J. Functional neurological disorders: the neurological assessment as treatment. Neurophysiol Clin 2014;44:363-373 3. Stone J, Reuber M, Carson A. Functional symptoms in neurology: mimics and chameleons. Pract Neurol 2013;13:104-113 4. Jones D, Drew P, Elsey C, et al. Conversational assessment in memory clinic encounters: interactional profiling for differentiating dementia from functional memory disorders. Aging Ment Health 2015; DOI:10.1080/13607863.2015.1021753 5. Coebergh JA, Wren DR, Mumford CJ. 'Undiagnosing' neurological disease: how to do it, and when not to. Pract Neurol 2014;14:436-439 6. Stone J, Pal S, Blackburn D. Functional (Psychogenic) Cognitive Disorders: A Perspective from the Neurology Clinic. J Alzheimers Dis 2015;48 Suppl 1:S5-S17

  Conflict of Interest:

  None declared

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  Conflict of Interest:
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• Published on: 14 April 2016

  A case of functional cognitive disorder with acute onset?

  • Rachel A Cichosz, Medical Student

  While reading Pennington et al's (2015) article on Functional Cognitive Disorder, I was struck by the similarity between their descriptions and a patient seen in clinic (patient X), with the exception that X's symptoms appeared over the course of a few days with no identifiable precipitating event. Extensive physical tests and brain imaging investigations were carried out and no organic disease was found yet symptoms we...

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  While reading Pennington et al's (2015) article on Functional Cognitive Disorder, I was struck by the similarity between their descriptions and a patient seen in clinic (patient X), with the exception that X's symptoms appeared over the course of a few days with no identifiable precipitating event. Extensive physical tests and brain imaging investigations were carried out and no organic disease was found yet symptoms were reportedly severe and having a major impact on X's functioning. Here I discuss X's case (with identifiable information changed in order to respect patient confidentiality) and propose that there may be a sub-type of functional cognitive disorder with an acute onset.

  Patient X is a 48 year old house-wife and local preacher. She presented to clinic with her husband after being referred by her GP due to the development of severe confusion and cognitive impairment developing from a previously high level of functioning just a few days earlier. Symptoms began to appear on the Sunday evening and peaked on the Tuesday, with no change between then and the clinic assessment (Thursday). X reported completely 'losing track of time' and reported severe memory loss which her husband had first noticed. During the assessment, she claimed inability to answer any of our questions herself and repeatedly looked to her husband for answers. When asked why she could not answer the questions, she said that she 'could not remember' and described problems with attention, concentration and executive function. This appeared inconsistent with her performance in daily life as she had managed to maintain her previous social roles, although we had no objective baseline for comparison.

  X had no previous psychiatric history and no significant medical history. She was not taking any regular medications except for the oral contraceptive pill. She reported a normal upbringing. The only identifiable recent stressor was that X had recently started a new university course, part of which involved looking at different personality types, which she said had 'confused' and 'worried' her.

  It was first thought that she may have organic disease as her symptoms came on suddenly, however she returned to psychiatry clinic following extensive tests as no physical cause could be found. Could this be a case of functional cognitive disorder with acute onset? Further assessment and follow-up of patient X and others like her could unravel a subgroup of patients who fall into this category.

  Conflict of Interest:

  None declared

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