JNNP Online First, published on June 1, 2016 as 10.1136/jnnp-2015-312945 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp-2015-312945 on 1 June 2016. Downloaded from Cognitive neurology RESEARCH PAPER Utility of testing for apraxia and associated features in dementia Samrah Ahmed,1 Ian Baker,2 Sian Thompson,3 Masud Husain,1,4 Christopher R Butler1 1Nuffield Department of ABSTRACT apraxia refers to difficulty pantomiming learned Clinical Neurosciences, Introduction Existing literature suggests that the actions such as brushing the teeth or combing the University of Oxford, John Radcliffe Hospital, Oxford, UK presence or absence of apraxia and associated parietal hair; ideational apraxia describes an inability to 2Russell Cairns Unit, Oxford deficits may be clinically relevant in differential diagnosis carry out complex sequences of actions in everyday University Hospitals NHS Trust, of dementia syndromes. life, such as making a cup of tea.3 John Radcliffe Hospital, Aim This study investigated the profile of these features A survey of the existing literature reveals Oxford, UK 3 in Alzheimer’s disease (AD) and frontotemporal dementia common observations of apraxia in amnestic Department of Clinical fi ’ Neurology, Oxford University (FTD) spectrum disorders, at rst presentation. Alzheimer s disease (AD). Apraxia is a diagnostic Hospitals NHS Trust, Oxford, Methods Retrospective case note analysis was feature of amnestic AD, included in the UK undertaken in 111 patients who presented to the Oxford NINCDS-ADRDA (National Institute of 4 Department of Experimental Cognitive Disorders Clinic, Oxford, UK, including 29 Neurological and Communicative Diseases and Psychology, University of amnestic AD, 12 posterior cortical atrophy (PCA), 12 Stroke-Alzheimer’s Disease and Related Disorders Oxford, John Radcliffe 45 Hospital, Oxford, UK logopenic primary progressive aphasia (lvPPA), 20 Association) criteria. Ideomotor and ideational behavioural variant FTD (bvFTD), 7 non-fluent variant apraxia have been reported in amnestic AD,6 with Correspondence to PPA (nfvPPA), 6 semantic variant PPA (svPPA) and 25 the former being reported as being more prevalent, fi Dr Samrah Ahmed, Nuf eld patients with subjective cognitive impairment (SCI). The although not ubiquitous.7 Limb apraxias have also Department of Clinical Neurosciences, University of clinical features of interest were: limb apraxia, apraxia of been observed in the clinical variants of AD, 8 Oxford, John Radcliffe speech (AOS), and left parietal symptoms of dyslexia, including posterior cortical atrophy (PCA) and Hospital, Oxford OX3 9DU, dysgraphia, and dyscalculia. logopenic variant primary progressive aphasia UK; [email protected]. Results The prevalence of limb apraxia was highest in (lvPPA).910 ac.uk PCA, amnestic AD, lvPPA and nfvPPA. AOS was only The prevalence of apraxia has been less systemat- Received 17 December 2015 observed in nfvPPA. Associated parietal features were ically examined in frontotemporal dementia (FTD) Revised 31 March 2016 more prevalent in AD spectrum than FTD spectrum disorders of semantic (svPPA) and non-fluent Accepted 27 April 2016 disorders. Group comparisons between key differential variant PPA (nfvPPA), or behavioural variant FTD diagnostic challenges showed that lvPPA and nfvPPA (bvFTD). Limb apraxia has been observed in a sub- could be significantly differentiated on the presence of stantial minority of patients with nfvPPA,11 12 left parietal features and AOS, and amnestic AD could although the defining feature of apraxia of speech be differentiated from bvFTD, svPPA and SCI by limb (AOS), an acquired speech disorder which affects http://jnnp.bmj.com/ apraxia. Regression analysis showed that limb apraxia the motor programming system required for speech could successfully differentiate between AD and FTLD production,13 was more consistently found.12 In spectrum disorders with 83% accuracy. this group, limb apraxia occurred with greater fre- Discussion Disease-specificprofiles of limb apraxia quency than in patients with lvPPA.11 A more and associated deficits can be observed. FTD and AD recent study found that patients with amnestic AD spectrum disorders can be difficult to differentiate due to performed significantly worse than patients with overlapping cognitive symptoms, and measures of bvFTD on tests of limb apraxia, examining both on September 27, 2021 by guest. Protected copyright. apraxia, in particular, appear to be a promising ideational and ideomotor gestures.14 discriminator. It is widely held that the left parietal lobe plays a central role in limb apraxia, originating in Leipmann’s early model describing a posterior to INTRODUCTION anterior stream that converts mental images of Apraxia is a disorder of higher-order motor skills actions into a motor response,2 and subsequent and learned movements, in the absence of paresis, models have equally attributed a central role to the abnormal muscle tone, cerebellar ataxia sensory left parietal regions.115In conjunction with impairment or comprehension deficits.12Apraxia apraxia, left parietal dysfunction produces a range has been associated with various dementia syn- of other cognitive symptoms, including deficits in dromes but, although simple to test for at the reading, writing and arithmetic, and there is sugges- bedside, its use in the differential diagnosis of tion in the literature that these clinical features may To cite: Ahmed S, Baker I, dementia is not well established. Several forms of also be of relevance to the diagnosis of dementia Thompson S, et al. J Neurol apraxia are often distinguished, such as constructive syndromes, particularly in the AD spectrum. The Neurosurg Psychiatry fi Published Online First: apraxia, gait apraxia and trunk apraxia. The clinical neuropsychological pro le of patients with lvPPA, [please include Day Month manifestations relevant to this study are those where pathology is focused on the left inferior par- Year] doi:10.1136/jnnp- affecting limb movements. Limb apraxia is typically ietal lobe, includes dyscalculia, and phonological 2015-312945 described in terms of two major types: ideomotor alexia as well as limb apraxia10 and dysgraphia.16 17 Ahmed S, et al. J Neurol Neurosurg Psychiatry 2016;0:1–5. doi:10.1136/jnnp-2015-312945 1 Copyright Article author (or their employer) 2016. Produced by BMJ Publishing Group Ltd under licence. J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp-2015-312945 on 1 June 2016. Downloaded from Cognitive neurology In a series of 19 patients with PCA, McMonagle et al8 reported creating meaningless gestures and postures using the left and that 18 cases had dyslexia or dysgraphia while 16 had right hands; (C) pantomime the sequential steps involved in dyscalculia. performing a complex task on verbal command, for example Although the existing literature suggests that the presence or ‘show me how you would make a cup of tea’. absence of apraxia and associated parietal deficits might be clin- 2. Speech articulation: Apraxia of speech was defined according ically relevant in differential diagnosis, to date there has, to our to published criteria,13 which include effortful, halting speech knowledge, been no systematic examination of apraxia and asso- with the presence of speech sound errors and distortions. ciated features in a large number of patients with different 3. Associated left parietal features: Existing literature points to dementia syndromes. The aim of this study is to determine the three features of interest: dysgraphia, defined as impairment profile of these features in AD and FTD spectrum disorders, at of well-formed and linguistically correct script; dyslexia, initial clinical presentation. defined as a disturbance in the ability to read and spell; and dyscalculia, defined as an impairment in the ability to com- METHODS AND MATERIALS prehend or write numbers properly, or to manipulate Participants numbers to perform simple calculations.3 Corroboration of All patients were assessed at clinical presentation at the Oxford the presence or absence of these features was determined Cognitive Disorders Clinic, Oxford, UK. A total of 111 patients from the ACE-R, where available. were entered into the study with the following clinical diagno- ses: 29 amnestic AD, 12 PCA, 12 lvPPA, 20 bvFTD, 7 nfvPPA Statistical analysis and 6 svPPA. All patients recruited for the study fulfilled con- Group differences in demographic and clinical characteristics sensus criteria for disease (PCA;818lvPPA, nfvPPA and svPPA;13 were examined using one-way analysis of variance. Group com- amnestic AD;45or bvFTD19), based upon clinical assessment, parisons of clinical features were examined using Fisher’s exact brain imaging and detailed neuropsychological assessment. Case test. Binary logistic regression was used to determine if any of notes for all patients seen in the Oxford Cognitive Disorders the clinical features could be used to predict diagnostic category. Clinic between 2010 and 2015 who had a diagnosis of an AD Cross validation of the regression analyses was undertaken by (amnestic AD, lvPPA, PCA) or FTD (bvFTD, svPPA or nfvPPA) taking a random sample of half of the patients from the original spectrum disorder were examined. Mean follow-up time for sample, and repeating the binary logistic regression analyses. patients was 22.7 months; 25 patients with subjective cognitive impairment (SCI) were also included as a control group, as well RESULTS as an important clinical comparison group. Patients with SCI Demographic and clinical