Reduplicative paramnesia after a right frontal lesion

The Department of Neurology, IMS Itabashi Rehabilitation Hospital, Azusawa, Itabashi-ku, Tokyo, Japan.
Cognitive and behavioral neurology: official journal of the Society for Behavioral and Cognitive Neurology (Impact Factor: 0.95). 04/2011; 24(1):35-9. DOI: 10.1097/WNN.0b013e31821129b7
Source: PubMed

ABSTRACT To report a case of reduplicative paramnesia after a focal lesion localized in the right frontal subcortical region.
It is suggested that a right frontal subcortical lesion alone may be sufficient to cause cognitive disturbance that can develop into reduplicative paramnesia. Clinical data have been scarce.
We describe the clinical, neuropsychological, and neuroradiologic findings of a 69-year-old man with reduplicative paramnesia after a right frontal subcortical lesion.
Observation and neuropsychological study showed visuospatial impairment, visual-dominant memory disturbance, anosognosia for cognitive disturbance, and mild frontal dysfunction with paranoid personality. Diffusion-weighted magnetic resonance imaging study showed a lesion localized in the right inferior posterior frontal subcortical area, and we could define 5 neural pathways involved with the lesion. We supposed that 4 of these were potentially related to reduplicative paramnesia: the medial inferior component of the superior longitudinal fasciculus and the fronto-occipital fasciculus, which are related to visuospatial processing; the anterior thalamic radiation, which is concerned with memory processes; and the uncinate fasciculus, which may be related to abnormal feelings of hyperfamiliarity.
A localized lesion in the right inferior posterior frontal subcortical area can cause cognitive dysfunction that may develop into reduplicative paramnesia. Paranoid personality and the change of the patient's hospital room might have triggered the reduplicative delusion in this case.

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    • "The uncinate itself has been implicated in at least two studies. Lee et al. (2011) found an uncinate lesion in a patient suffering from reduplicative paramnesia in the absence of other delusions (aside from anasognosia). This patient had an average IQ and normal language and autobiographical memory. "
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    ABSTRACT: The uncinate fasciculus is a bidirectional, long-range white matter tract that connects lateral orbitofrontal cortex and Brodmann area 10 with the anterior temporal lobes. Although abnormalities in the uncinate fasciculus have been associated with several psychiatric disorders and previous studies suggest it plays a putative role in episodic memory, language and social emotional processing, its exact function is not well understood. In this review we summarize what is currently known about the anatomy of the uncinate, we review its role in psychiatric and neurological illnesses, and we evaluate evidence related to its putative functions. We propose that an overarching role of the uncinate fasciculus is to allow temporal lobe-based mnemonic associations (e.g. an individual's name + face + voice) to modify behaviour through interactions with the lateral orbitofrontal cortex, which provides valence-based biasing of decisions. The bidirectionality of the uncinate fasciculus information flow allows orbital frontal cortex-based reward and punishment history to rapidly modulate temporal lobe-based mnemonic representations. According to this view, disruption of the uncinate may cause problems in the expression of memory to guide decisions and in the acquisition of certain types of learning and memory. Moreover, uncinate perturbation should cause problems that extend beyond memory to include social-emotional problems owing to people and objects being stripped of personal value and emotional history and lacking in higher-level motivational value.
    Brain 05/2013; 136(6). DOI:10.1093/brain/awt094 · 9.20 Impact Factor
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    ABSTRACT: Background: Reduplicative paramnesia (RP) is a content-specific delusional misidentification syndrome (DMS) which has received little attention in the research literature relative to other DMS. RP is thought to result from an organic rather than psychiatric cause distinguishing it from other DMS. Our systematic review examines the research literature investigating the prevalence, symptomatology and potential neurologic mechanisms underlying RP. Sampling and methods: MEDLINE, PsycINFO, and the Cochrane Library were searched (from 1966 to February 10, 2012) with the reference lists of relevant articles examined. Case reports, clinical studies and post-mortem studies focusing on, or referring to, RP were included. Results: There is a paucity of literature regarding the potential mechanisms underlying the psychological, cognitive and neurological aspects of RP. The available literature is limited by the lack of systematic clinical studies and in vivo investigations with current findings remaining only speculative. However, there does appear to be a consensus that RP may have a neurologic rather than psychiatric cause and that right and bifrontal lesions as well as the cognitive dissonance associated with memory, visuospatial and impaired conceptual integration are common factors in RP presentation. Conclusions: This area requires further extensive systematic research with supplementary in vivo data. Current studies suggest that focal lesions within the frontal lobe may account for the onset of RP.
    Psychopathology 07/2012; 45(6):337-43. DOI:10.1159/000337748 · 2.08 Impact Factor
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