A man in his 80s presented with gradual onset of a persistent and delusion-like perception that novel encounters are repetitions of previous experiences. Within 2 years of symptom onset, he had impaired verbal memory and executive dysfunction on neuropsychological assessment. Cerebrospinal fluid core Alzheimer's disease (AD) biomarkers analysis supported probable AD. Generalised and left temporal atrophy was seen on MRI of the brain. Neurological fludeoxyglucose-positron emission tomography (PET)/CT showed left temporal and bilateral frontal lobe hypometabolism. His presenting symptom is known as déjà vécu with recollective confabulation, a rare phenomenon associated with AD and other neurodegenerative disorders. While several potential mechanisms have been previously proposed, the fludeoxyglucose-PET/CT hypometabolism in the temporal and frontal lobes in this case suggests dual deficits in recognition memory and metacognition may be culprit mechanisms. Although uncommon, déjà vécu with recollective confabulation is a fascinating phenomenon that can provide a unique insight into memory and delusional processes in dementia.

OBJECTIVE:We aimed to (i) compare the clinical, neuropsychological, and neuroimaging characteristics of unprovoked late-onset epilepsy (LOE) patients with cognitive symptoms against probable Alzheimer's disease (AD) patients; (ii) clarify how neurodegeneration and other processes could be implicated in the cognitive symptoms of unprovoked LOE patients; and (iii) characterize the longitudinal trajectory of unprovoked LOE patients with cognitive symptoms. METHODS:Twenty-six unprovoked LOE patients with cognitive symptoms and 26 probable AD were retrospectively recruited from epilepsy and memory clinics at a single tertiary referral center. The patients underwent comprehensive clinical, neuropsychological, and 18Fluorodeoxyglucose PET-CT assessments. All LOE patients had clinical follow-up and a subset of 17 patients had repeat neuropsychological assessments. RESULTS:At baseline, 18% of LOE patients with cognitive symptoms had dementia-range cognitive impairment and one received a diagnosis of probable AD. Compared with the probable AD group, the LOE group did not perform significantly better in global measures of cognition (total ACE-III), neuropsychological tests for fluency, working memory, language, attention, or executive function, but performed better in naming, memory, and visuospatial ability. The commonest patterns of cognitive impairment in the LOE group were frontal and left temporal, whereas all AD patients exhibited parietotemporal patterns. The AD group had more 18Fluorodeoxyglucose PET-CT hypometabolism in the parietal and occipital, but not the temporal and frontal lobes. During the 3.0 ± 3.2 years follow-up, improved seizure frequency in the LOE group covaried with improved total ACE-III score, there was no further conversion to probable AD and no group-level cognitive decline. CONCLUSION:Unprovoked LOE patients with cognitive symptoms had varying severities of cognitive impairment, and different patterns of cognitive and imaging abnormalities compared with AD patients. They were rarely diagnosed with probable AD at presentation or follow-up. Cognitive outcome in LOE may be related to seizure control. Cerebral small vessel disease may play a role in LOE-associated cognitive impairment.

Introduction: Patients with vestibular disorders sometimes report cognitive difficulties, but there is no consensus about the type or degree of cognitive complaint. We therefore investigated subjective cognitive dysfunction in a well-defined sample of neuro-otology patients and used demographic factors and scores from a measure of depression, anxiety, and stress to control for potential confounding factors. Methods: We asked 126 neuro-otology clinic outpatients whether they experienced difficulties with thinking, memory, or concentration as a result of dizziness or vertigo. They and 42 nonvertiginous control subjects also completed the Neuropsychological Vertigo Inventory (NVI, which measures cognitive, emotional, vision, and motor complaints), the Everyday Memory Questionnaire (EMQ), and Depression, Anxiety, and Stress Scales (DASS). Results: In the initial interview questions, 60% of patients reported experiencing cognitive difficulties. Cognitive questionnaire scores were positively correlated with the overall DASS score and to a lesser extent with age and gender. Therefore, we compared patients and controls on the NVI and EMQ, using these mood and demographic variables as covariates. Linear regression analyses revealed that patients scored significantly worse on the total NVI, NVI cognitive composite, and 3 individual NVI cognition subscales (Attention, Space Perception, and Time Perception), but not the EMQ. Patients also scored significantly worse on the NVI Emotion and Motor subscales. Conclusions: Patients with dizziness and vertigo reported high levels of cognitive dysfunction, affecting attention, perceptions of space and time. Although perceptions of cognitive dysfunction were correlated with emotional distress, they were significantly elevated in patients over and above the impact of depression, anxiety, or stress.

Leptomeningitis is a rare central nervous system manifestation of rheumatoid arthritis, generally in patients with established chronic rheumatoid disease. We report a 41-year-old man without previous rheumatoid arthritis or psychiatric disorder who presented with an acute neuropsychiatric disturbance and polyarthralgia. His MR scan of brain showed asymmetric bifrontal leptomeningitis, confirmed on (18F)-fluoro-D-glucose-positron emission tomography. Other investigations showed highly positive serum and cerebrospinal fluid anti-cyclic citrullinated peptide. A leptomeningeal biopsy showed necrotising leptomeningeal inflammation with ill-defined granulomas and lymphoplasmacytic infiltrate without organisms. Prolonged high-dose corticosteroids and then rituximab resulted in recovery. Chronic leptomeningitis can present with an acute neuropsychiatric disorder. We highlight that early rheumatoid disease can, rarely, cause a chronic leptomeningitis, reversible with immunotherapy.

In déjà vu, the feeling that what we are currently experiencing we have experienced before is fleeting and is not accepted as true. In contrast, in déjà vecu or "recollective confabulation", the sense of déjà vu is persistent and convincing, and patients genuinely believe that they have lived through the current moment at some previous time. In previous reports of cases of déjà vecu, both personal events and non-personal, world events gave rise to this experience. In this paper we describe a patient whose déjà vecu experiences are entirely restricted to non-personal events, suggesting that autobiographical and non-autobiographical episodic memory processing can dissociate. We suggest that this dissociation is secondary to differences in the degree to which personal and emotional associations are formed for these two different types of event, and offer a two-factor theory of déjà vecu.

Although semantic dementia (SD) is defined as a selective disruption of conceptual knowledge, a number of group studies have now demonstrated that SD patients also show impaired performance on tasks not usually considered to have a high semantic load (e.g., reading words aloud and lexical or object decision). The aim of the current study was to document the relative deterioration, over time, of a number of semantic and so-called 'non-semantic' tasks in LF, a single case of SD for whom - by virtue of his work as a published cartoonist - we also have extensive data regarding his pre-morbid linguistic and drawing skills.In five testing rounds over a period of five years we administered semantic tests of object naming and object definition (on both of which LF was progressively impaired, as expected for a diagnosis of SD), plus verbal and non-verbal 'non-semantic' tasks of reading aloud, spelling, object and lexical decision, and delayed copy drawing.Initially, his only striking 'non-semantic' deficit was in the domain of spelling - a pronounced surface dysgraphia in an individual with demonstrably superior pre-morbid spelling skill. Over time, and in line with his declining semantic system, LF's performance gradually deteriorated on all of the 'non-semantic' tasks. The most vulnerable items on most tasks were those with low frequency and an atypical form.This report adds to the growing body of evidence that a number of cognitive processes not usually considered to be 'semantic' in their demands rely on the integrity of semantic knowledge for successful execution. Furthermore, it provides the first indication that these non-semantic deficits might emerge in an order predictable from the typicality structure of the relevant domain. Crown Copyright (C) 2008 Published by Elsevier Srl. All rights reserved.

Prosopagnosia is currently viewed within the constraints of two competing theories of face recognition, one highlighting the analysis of features, the other focusing on configural processing of the whole face. This study investigated the role of feature analysis versus whole face configural processing in the recognition of facial expression. A prosopagnosic patient, SC made expression decisions from whole and incomplete (eyes-only and mouth-only) faces where features had been obscured. SC was impaired at recognizing some (e.g., anger, sadness, and fear), but not all (e.g., happiness) emotional expressions from the whole face. Analyses of his performance on incomplete faces indicated that his recognition of some expressions actually improved relative to his performance on the whole face condition. We argue that in SC interference from damaged configural processes seem to override an intact ability to utilize part-based or local feature cues.

Anarchic hand syndrome is characterised by unintended but purposeful and autonomous movements of the upper limb and intermanual conflict. Based on predictions of internal models of movement generation, we examined the role of visual cues in unimanual and bimanual movements in a patient with anarchic hand syndrome and in a matched control. In Experiment 1, participants made unimanual movements in a sequential button-pressing task. The cue for the next target in a sequence appeared either prior to (exogenous) or after (endogenous) the initiation of movement. For the patient, performance of the anarchic left hand was selectively impaired in the endogenous condition. In Experiment 2, participants made unimanual movements on a digitising tablet to a target, which appeared either alone or with a distractor. While the presence of a distractor was associated with increased Initiation time in general, the patient's anarchic left hand was particularly vulnerable to disruption by the distractor. The findings of Experiments 1 and 2 indicate excessive reliance on salient environmental stimuli for movement production in anarchic hand syndrome. We conclude that in AHS goal-directed actions of the affected limb are particularly vulnerable to disruption by non-relevant information. Finally, in Experiment 3, participants performed unimanual and mirror-image bimanual movements on a digitising tablet to targets in the left or right hemispace. Coupling of the parameters of the two hands was evident such that, compared with a unimanual baseline, Initiation time of the intact right hand deteriorated while it improved for the anarchic left hand.

INTRODUCTION:This study investigated a patient with a delusion of misidentification (DM) resembling a Capgras delusion. Instead of the typical Capgras delusion--the false belief that someone has been replaced by an almost identical impostor--patient MF misidentified his wife as his former business partner.METHOD:Detailed investigation of MF's face processing, affective response and affect perception, and ability to evaluate, and reject, implausible ideas was undertaken.RESULTS:MF's visual processing of identity, gender, and age of familiar and unknown faces was intact but he was unable to identify the facial expressions of anger, disgust, and fear, or to match faces across expressions. MF also showed a reduced affective responsiveness to his environment, and impaired reasoning ability.CONCLUSIONS:We propose that MF's delusion of misidentification resulted from a combination of affective deficits, including impairment of both affective response and affect perception, in addition to an inability to evaluate, and reject, implausible ideas. These deficits, in combination with specific life events at the time of onset of the delusion, may have contributed to the form and content of the delusion. In addition, the results raise the possibility that the processing of face identity and facial expression are not as independent as previously proposed in models of face processing.

We present two patients in whom the mirror sign, the inability to recognize one's own reflected image, was a stable and persisting symptom signalling the onset of a progressive dementing illness. Extensive neuropsychological testing was conducted with both patients, with particular emphasis on face processing and the understanding of reflected space. Both patients were also investigated with structural imaging techniques (computed tomography and magnetic resonance imaging). Although the neuroimaging results were not strongly lateralizing for either patient, neuropsychological testing revealed striking right hemisphere dysfunction with relatively intact left hemisphere cognitive function in both patients. Of particular interest was the patients' dissociation on tests of face processing; one patient, FE, had significant face processing deficits while the other patient, TH, had relatively intact face processing. Further testing with TH revealed striking deficits in his ability to interpret reflected space. The results of the face processing tests are discussed in the context of current models of normal face processing, with particular emphasis on the affective component in face recognition. We propose that a combination of cognitive deficits underlie the mirror sign delusion, including perceptual, affective and reasoning impairments, and also discuss the contributions of cortical and subcortical lesions in these two patients and in delusions in general.

We provide a battery of examples of delusions against which theoretical accounts can be tested. Then we identify neuropsychological anomalies that could produce the unusual experiences that may lead, in turn, to the delusions in our battery. However, we argue against Maher's view that delusions are false beliefs that arise as normal responses to anomalous experiences. We propose, instead, that a second factor is required to account for the transition from unusual experience to delusional belief. The second factor in the etiology of delusions can be described superficially as a loss of the ability to reject a candidate for belief on the grounds of its implausibility and its inconsistency with everything else that the patient knows, but we point out some problems that confront any attempt to say more about the nature of this second factor.

We provide a battery of examples of delusions against which theoretical accounts can be tested. Then we identify neuropsychological anomalies that could produce the unusual experiences that may lead, in turn, to the delusions in our battery. However, we argue against Maher's view that delusions are false beliefs that arise as normal responses to anomalous experiences. We propose, instead, that a second factor is required to account for the transition from unusual experience to delusional belief. The second factor in the etiology of delusions can be described superficially as a loss of the ability to reject a candidate for belief on the grounds of its implausibility and its inconsistency with everything else that the patient knows, but we point out some problems that confront any attempt to say more about the nature of this second factor.

Four detailed cases of delusions of misidentification (DM) are presented: two cases of misidentification of the reflected self, one of reverse intermetamorphosis, and one of reduplicative paramnesia. The cases are discussed in the context of three levels of interpretation: neurological, cognitive and phenomenological. The findings are compared to previous work with DM patients, particularly the work of Ellis and Young (1990; Young, 1998) who found that loss of the normal affective response to familiar faces was a contributing factor in the Capgras delusion. The four cases presented suggest that this particular deficit is not a critical factor in the development of other forms of DM.

The "two-route model of face recognition" proposed by Bauer (1984) and adopted by Ellis and Young (1990), has become a widely accepted model in studies of face processing disorders, including both prosopagnosia and the delusional misidentification syndromes. We review the origin and application of the two-route model of face recognition in examining both the neuroanatomical pathways and the cognitive pathways to face recognition. With respect to the neuroanatomy, we conclude that face recognition is subserved by a single pathway, the ventral visual pathway, as there is no evidence to suggest that the dorsal visual pathway is capable of visual recognition or of providing an affective response to familiar stimuli. We demonstrate how operation of the ventral visual pathway and its connections to the amygdala can parsimoniously account for the findings in the literature on prosopagnosia and delusional misidentification syndromes. In addition, we propose a cognitive model of face processing stemming from the work of Bruce and Young (1986). Our model involves two pathways subsequent to the system responsible for face recognition: one pathway to a system containing semantic and biographical information about the seen face, and a second pathway to a system responsible for the generation of an affective response to faces that are familiar. We demonstrate how this cognitive model can explain the dissociations between overt and covert recognition observed in prosopagnosia and the Capgras delusion.