Article

The Relationship Between Schizophrenia and Frontotemporal Dementia.

1Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL, USA.
Journal of Geriatric Psychiatry and Neurology (Impact Factor: 3.53). 06/2013; DOI: 10.1177/0891988713490992
Source: PubMed

ABSTRACT Schizophrenia is a relatively common disorder diagnosed by the presentation of psychotic symptoms in the absence of identifiable neurologic or other organic cause. Frontotemporal dementia (FTD) is a relatively rare progressive neurodegenerative disorder that can present with a multitude of cognitive and behavioral symptoms including psychosis. At times, this phenotypic overlap can mean that schizophrenia and FTD are 2 possibilities in the differential diagnosis of a psychotic presentation. In this article, we systematically review the literature on the relationship between schizophrenia and FTD including case reports that highlight the potential for diagnostic confusion, clinical studies examining the relationship between the disorders, and the molecular evidence of shared pathophysiologic mechanisms. Although a relationship between the disorders is not definitively supported by the current literature, we identify the characteristics of a psychotic presentation that should alert the clinician to the possibility of FTD and describe the areas where further research is needed to clarify the pathophysiologic relationship.

0 Bookmarks
 · 
199 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Although structural magnetic resonance imaging (sMRI) and neuropathological investigations offer complementary information that can be used to formulate and test hypotheses about pathophysiological mechanisms in psychiatric disorders, the findings from these two fields are seldom integrated in a systematic manner. In this study, we overview recent sMRI findings in schizophrenia and bipolar disorder and consider how they relate to neuropathological data. sMRI research indicates that schizophrenia is associated with volumetric reductions in a network of frontal, temporal, limbic, striatal, and thalamic regions. Some of these abnormalities are apparent prior to psychosis onset and may progress with ongoing illness. sMRI findings in bipolar disorder have been more variable, with both volumetric increases and decreases being reported across several brain regions at different illness stages. Neuropathological studies of both patient groups suggest the cellular changes associated with these volumetric differences affect diverse tissue compartments in a regionally heterogeneous way. These findings suggest that any putative pathophysiological mechanism in schizophrenia or bipolar disorder should account for the dynamic, complex, and regionally heterogeneous brain abnormalities seen in these patients. We contend that greater integration of the findings from these two fields will facilitate more targeted and hypothesis-driven research in the future.
    Current opinion in psychiatry 06/2009; 22(3):312-9. · 3.57 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Functional brain imaging studies of patients with schizophrenia may be grouped into those that assume that the signs and symptoms of schizophrenia are due to disordered circuitry within a critical brain region and studies that assume that the signs and symptoms are due to disordered connections among brain regions. Studies have investigated the disordered functional brain anatomy of both the positive and negative symptoms of schizophrenia. Studies of spontaneous hallucinations find that although hallucinations are associated with abnormal brain activity in primary and secondary sensory areas, disordered brain activation associated with hallucinations is not limited to sensory systems. Disordered activation in non-sensory regions appear to contribute to the emotional strength and valence of hallucinations, to be a factor underlying an inability to distinguish ongoing mental processing from memories, and to reflect the brain's attempt to modulate the intensity of hallucinations and resolve conflicts with other processing demands. Brain activation studies support the view that auditory/verbal hallucinations are associated with an impaired ability of internal speech plans to modulate neural activation in sensory language areas. In early studies, negative symptoms of schizophrenia were hypothesized to be associated with impaired function in frontal brain areas. In support of this hypothesis meta-analytical studies have found that resting blood flow or metabolism in frontal cortex is reduced in schizophrenia, though the magnitude of the effect is only small to moderate. Brain activation studies of working memory (WM) functioning are typically associated with large effect sizes in the frontal cortex, whereas studies of functions other than WM generally reveal smaller effects. Findings from some functional connectivity studies have supported the hypothesis that schizophrenia patients experience impaired functional connections between frontal and temporal cortex, although the nature of the disordered connectivity is complex. More recent studies have used functional brain imaging to study neural compensation in schizophrenia, to serve as endophenotypes in genetic studies and to provide biomarkers in drug development studies. These emerging trends in functional brain imaging research are likely to help stimulate the development of a general neurobiological theory of the complex symptoms of schizophrenia.
    Current topics in behavioral neurosciences. 01/2010; 4:181-214.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Neuropsychological deficits among schizophrenia patients have been consistently documented in research over the past 20 years and are reviewed in this chapter. Discussion of general abilities is presented as a background and is followed by analysis of functioning in specific cognitive domains. Overall intellectual deficits are indicated by results from both general intelligence tests and composite test battery scores. Within specific cognitive domains, effect size differences are noted in numerous areas, including attention, with indications that working memory is affected more severely than simple attention, likely due to inclusion of an executive component in such tasks. There is also evidence of slowed processing speed among schizophrenia patients, likely contributing to deficits in other domains which rely on rapid and efficient assimilation of information. Executive impairments have been found on tests assessing set-shifting abilities, selective attention, and inhibition of inappropriate responses. Learning and memory deficits have been demonstrated extensively, with some evidence that recall of verbal material is more affected than recall of visual information, and that recognition abilities are comparatively less impaired than recall for both modalities. Receptive and expressive language abilities are compromised in schizophrenia patients, as well as visual perceptual, constructional, and fine motor skills. Social cognition is an area of particular importance due to its relevance to functional outcome. Deficits in expression and recognition of facial and prosodic affect have been demonstrated, although subjective experience of emotion appears to be relatively well preserved. Neuropsychological deficits described in this review appear to generally remain stable throughout adulthood, supporting neurodevelopmental, rather than neurodegenerative, models of the illness. Finally, cognitive deficits are increasingly used as endophenotypes, which is likely an important direction of future research.
    Current topics in behavioral neurosciences. 01/2010; 4:373-90.

Full-text

Download
61 Downloads
Available from
May 21, 2014