White matter microstructural abnormalities in the frontal lobe of adults with antisocial personality disorder

Department of Psychiatry, Royal College of Surgeons in Ireland, Dublin, Ireland.
Cortex (Impact Factor: 6.04). 07/2011; 48(2):216-29. DOI: 10.1016/j.cortex.2011.06.005
Source: PubMed

ABSTRACT Antisocial personality disorder (ASPD) and psychopathy involve significant interpersonal and behavioural impairments. However, little is known about their underlying neurobiology and in particular, abnormalities in white matter (WM) microstructure. A preliminary diffusion tensor magnetic resonance imaging (DT-MRI) study of adult psychopaths employing tractography revealed abnormalities in the right uncinate fasciculus (UF) (Craig et al., 2009), indicating fronto-limbic disconnectivity. However, it is not clear whether WM abnormalities are restricted to this tract or are or more widespread, including other tracts which are involved in connectivity with the frontal lobe. We performed whole brain voxel-based analyses on WM fractional anisotropy (FA) and mean diffusivity (MD) maps acquired with DT-MRI to compare 15 adults with ASPD and healthy age, handedness and IQ-matched controls. Also, within ASPD subjects we related differences in FA and MD to measures of psychopathy. Significant WM FA reduction and MD increases were found respectively in ASPD subjects relative to controls. FA was bilaterally reduced in the genu of corpus callosum while in the right frontal lobe FA reduction was found in the UF, inferior fronto-occipital fasciculus (IFOF), anterior corona radiata and anterior limb and genu of the internal capsule. These differences negatively correlated with measures of psychopathy. Also in the right frontal lobe, increased MD was found in the IFOF and UF, and the corpus callosum and anterior corona radiata. There was a significant positive correlation between MD and psychopathy scores. CONCLUSIONS: The present study confirms a previous report of reduced FA in the UF. Additionally, we report for the first time, FA deficits in tracts involved in interhemispheric as well as frontal lobe connectivity in conjunction with MD increases in the frontal lobe. Hence, we provide evidence of significant WM microstructural abnormalities in frontal brain regions in ASPD and psychopathy.

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Available from: Sagari Sarkar, May 23, 2014
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    • "It has also been reported that adult patients with acquired sociopathy due to orbitofrontal damage have intact knowledge of social rules and norms, though they are unable (or unwilling) to use this knowledge to guide decision making (Saver and Damasio, 1991). Interestingly, three studies have reported that the structure that links the ATL to orbitofrontal cortex, the uncinate fasiculus, is less organized in psychopaths or people with antisocial personality disorder compared with matched controls (Craig et al., 2009; Motzkin et al., 2011; Sundram et al., 2012 "
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    Social Cognitive and Affective Neuroscience 10/2012; 8(2). DOI:10.1093/scan/nss119 · 5.88 Impact Factor
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    • "We previously reported that adults with ASPD and psychopathy had a significant reduction in fractional anisotropy (FA) of the uncinate fasciculus (UF), a white-matter tract connecting the amygdala and OFC (Craig et al. 2009). A recent study also reported reduced FA of the UF alongside several other tracts (Sundram et al. 2012). FA value is derived from diffusion tensor MRI scanning (DT-MRI), and is an indicator of white-matter microstructural integrity through the quantification of directional differences in the diffusion of water molecules inside tissues. "
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    • "Functional studies in humans revealed activation of the fronto-temporal network mediated by the uncinate in tasks involving integration of emotional material (Hung et al., 2010; Park et al., 2010), recall of emotionally stimulating memories (Spoont et al., 2010), estimation of risks (Vorhold et al., 2007) or watching fearful faces (Grè zes et al., 2007; Pichon et al., 2009). Lesions to the uncinate connections lead to episodic memory disorders (Horel, 1978; Eacott and Gaffan, 1992; Levine et al., 1998; Fink et al., 2010) and antisocial behaviour (Dicks et al., 1969; Price et al., 2008; Craig et al., 2009; Sundram et al., 2012, this issue; Zappalà et al., 2012, this issue) both in humans and experimental conditions in monkeys. Humanesimian similarities were also found for the cingulum. "
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