Altered orbitofrontal sulcogyral pattern in schizophrenia

Abstract

Orbitofrontal alteration in schizophrenia has not been well characterized, likely due to marked anatomical variability. To investigate the presence of such alterations, we evaluated the sulcogyral pattern of this 'H-shaped' sulcus. Fifty patients with schizophrenia (100 hemispheres) and 50 age- and gender-matched control subjects (100 hemispheres) were evaluated using 3D high-spatial resolution MRI. Based on a previous study by Chiavaras and Petrides (2000), the sulcogyral pattern of the 'H-shaped' sulcus, which forms the boundaries of major orbitofrontal gyri, was classified into three types (Type I, II and III, in order of frequency) within each hemisphere. Chi-square analysis was performed to compare the sulcogyral pattern, and categorical regression was applied to investigate clinical/cognitive associations. The control data replicated the orbitofrontal sulcogyral pattern reported by Chiavaras and Petrides (P = 0.90-0.95), where the distribution was significantly different between the left and right hemisphere (Type I: right > left, Type II, III: left > right, chi2 = 6.41, P = 0.041). For schizophrenics, the distribution differed significantly from controls (chi2 = 11.90, P = 0.003), especially in the right hemisphere (chi2 = 13.67, P = 0.001). Moreover, the asymmetry observed in controls was not present in schizophrenia (chi2 = 0.13, P = 0.94). Specifically, the most frequent Type I expression was decreased and the rarest Type III expression was increased in schizophrenia, relative to controls. Furthermore, patients with Type III expression in any hemisphere evinced poorer socioeconomic status, poorer cognitive function, more severe symptoms and impulsivity, compared to patients without Type III expression. In contrast, patients with Type I in any hemisphere showed better cognitive function and milder symptoms compared to patients without Type I. Structurally, patients with Type III had significantly smaller intra-cranial contents (ICC) volumes than did patients without Type III (t(40) = 2.29, P = 0.027). The present study provides evidence of altered distribution of orbitofrontal sulcogyral pattern in schizophrenia, possibly reflecting a neurodevelopmental aberration in schizophrenia. Such altered sulcogyral pattern is unlikely to be due to secondary effects of the illness such as medication. Moreover, the structural association between Type III and small ICC volume, observed in the patient group, may suggest that Type III expression could be part of a systematic neurodevelopmental alteration, given that the small ICC volume could reflect early reduction of cranial growth driven by brain growth. The observed contrasting association of Type III expression with poorer outcome, and that of Type I expression with better outcome, further suggests clinical heterogeneity, and possible differences in treatment responsiveness in schizophrenia.

The effect of odor valence on olfactory performance in schizophrenia patients, unaffected relatives and at-risk youth

“…In addition, altered sulcogyral patterns in the orbitofrontal cortex (OFC), a key brain region involved in odor hedonic processing and sensory integration, were found to differentiate schizophrenia patients and individuals who convert to schizophrenia from non-converters and controls (Chakirova, Welch et al, 2010; Nakamura, Nestor et al, 2007). Therefore, odor valence measures, reflective of both hedonic disturbance and orbitofrontal impairment, could have predictive utility in identifying those at risk for the development of schizophrenia.…”

Modeling a model: Mouse genetics, 22q11.2 Deletion Syndrome, and disorders of cortical circuit development

“…5), as well as those with ADHD (McAlonan et al, 2005; Okugawa et al, 2007; Seidman et al, 2011; Silk et al, 2009); however, there is some indication that there may also be some increases in gray matter volume in ASD patients (Bonilha et al, 2008; Hazlett et al, 2006; McAlonan et al, 2005). There are also modest alterations in gyral/sulcal patterns (Nakamura et al, 2007; Nordahl et al, 2007; Watanabe et al, 2014). Finally, diffusion tensor-based analysis of MRI data (DTI) indicates that major corticocortical fiber tracts are disrupted in the brains of individuals with ASD, ADHD, and SCZ (Ashtari et al, 2005; Conturo et al, 2008; Phillips et al, 2011; Silk et al, 2009).…”

Anhedonia and individual differences in orbitofrontal cortex sulcogyral morphology

“…In non-clinical populations, Type I patterns tend to be the most common (56% of hemispheres), Type II slightly less common (30% of hemispheres), and Type III relatively rare (around 14% of hemispheres). In 2007, Nakamura et al observed that the frequency of expression of these patterns differs in populations with schizophrenia, where Type I patterns become significantly less common and rare, Type III patterns increase in frequency 11 . Such findings were corroborated by other research groups 12,13 .…”