Hippocampal and Amygdalar Local Structural Differences in Elderly Patients with Schizophrenia

Abstract

Objectives Morphological abnormalities have been reported for the hippocampi and amygdalae in young schizophrenia patients, but very little is known about the pattern of abnormalities in elderly schizophrenia patients. Here we investigated local structural differences in the hippocampi and amygdalae of elderly schizophrenia patients compared to healthy elderly subjects. We also related these differences to clinical symptom severity. Design 20 schizophrenia patients (mean age: 67.4±6.2 years, MMSE 22.8±4.4) and 20 healthy elderly subjects (70.3±7.5, 29.0±1.1) underwent high resolution magnetic resonance imaging of the brain. The Radial Atrophy Mapping technique was used to reconstruct the 3D shape of the amygdala and the hippocampus. Local differences in tissue reductions were computed between groups and permutation tests were run to correct for multiple comparisons, in statistical maps thresholded at p=0.05. Results Significant tissue reduction was observed bilaterally in the amygdala and hippocampus of schizophrenia patients. The basolateral-ventral-medial amygdalar nucleus showed the greatest involvement, with over 30% local tissue reduction. The centro-medial, cortical, and lateral nuclei were also atrophic in patients. The hippocampus showed significant tissue loss in the medio-caudal and antero-lateral aspects of CA1, and in medial section of its left head (pre- and para-subiculum;). In the left amygdala and hippocampus, local tissue volumes were significantly correlated with negative symptoms. Conclusions Tissue losses and altered morphology were found in elderly schizophrenia patients. Tissue loss mapped to amygdalo-hippocampal subregions known to have bidirectional and specific connections with frontal cortical and limbic structures and was related to clinical severity.

Hippocampal, amygdala and nucleus accumbens volume in first-episode schizophrenia patients and individuals at high familial risk: A cross-sectional comparison

“…as it is known to be involved in several relevant behaviours, such as anticipation and responses to rewards and aversive events which are known to be abnormal in schizophrenia (Chau et al 2004, Greer et al 2014. As these three structures share several efferent and afferent anatomical connections, it has been suggested that brain circuits involving these regions are impaired in schizophrenia (Moore et al 1999), which has been confirmed in a number of studies finding functional (Hall et al 2010) as well as volumetric alterations in these structures in schizophrenia (Lauer et al 161 2001, Prestia et al 2015, Kittel-Schneider et al 2015 Increasingly, it is being hypothesized that the brain deficit in schizophrenia is one of "dysconnectivity", i.e, either increased or decreased connectivity between regions (For a more detailed review, Please see chapter 1). As the hippocampus, amygdala and nucleus accumbens share several efferent and afferent anatomical connections, it has been suggested that brain circuits involving these regions are impaired in schizophrenia (For a review, see Grace, 2003).…”

Fatty acid binding proteins and the nervous system: Their impact on mental conditions

“…In human, MRI images revealed that patients with neurological and/or psychiatric diseases, including Alzheimer's disease, schizophrenia and depression, have a smaller volume of hippocampi than those of control subjects (Francis et al, 2013;Guo et al, 2014;Heckers and Konradi, 2010;Prestia et al, 2014;Reif et al, 2006;Rizos et al, 2014). One possibility for those findings is that neurogenesis may be decreased in those patients.…”

Aberrant Gray Matter Volume and Cortical Surface in Paranoid-Type Delusional Disorder

“…amygdala and OFC. To the best of our knowledge, structural abnormalities of the amygdala in individuals with pt-DD have not been specifically addressed, though alterations of amygdala have been frequently reported in patients with SZ [42][43][44][45][46][47], particularly in the context of facial affective processing [48,49]. The involvement of the amygdala in the processing of fear and threat is well-documented [50][51][52][53], but specific contributions of the amygdala to the development and persistence of delusions are still under debate [54].…”