Changes in cortical morphology resulting from long-term amygdala damage

Abstract

The amygdala's contribution to emotion, cognition and behavior depends on its interactions with subcortical and cortical regions. Amygdala lesions result in altered functional activity in connected regions, but it is not known whether there might be long-term structural sequelae as well. We hypothesized that developmental bilateral amygdala lesions would be associated with specific gray matter morphometric abnormalities in the ventromedial prefrontal cortex (vmPFC), anterior cingulate cortex (ACC) and the ventral visual stream. We conducted regions of interest and vertex-based analyses of structural MRI data acquired in two patients with long-standing focal bilateral amygdala lesions (S.M. and A.P.), compared to gender- and age-matched healthy comparison subjects. Both patients showed significant proportional increases in gray matter volume of the vmPFC. Cortical thickness was increased in the vmPFC and ACC and decreased in the ventral visual stream. There were no morphometric changes in dorsolateral prefrontal cortex or dorsal visual stream cortices. These findings support the hypothesis that cortical regions strongly connected with the amygdala undergo morphometric changes with long-standing amygdala damage. This is the first evidence in humans of the remote alteration of brain morphology in association with amygdala lesions, and will help in interpreting the structural and functional consequences of amygdala pathology in neuropsychiatric disorders.

Neural Reorganization Due to Neonatal Amygdala Lesions in the Rhesus Monkey: Changes in Morphology and Network Structure

“…Nonetheless, a recent report on 2 human subjects with longterm, early onset amygdalar damage (Boes et al 2012) demonstrated anomalies in cortical thickness, including both increases and decreases, bearing a spatial distribution with striking resemblance to the results reported here (Fig. 7).…”

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“…As Williams syndrome has been associated with changes in AMG functioning [85][86][87], it provides important clues for the role of the AMG. One study reported that long-term damage to the entire AMG did lead to morphometric changes in the ventral stream, but not the dorsal stream [88]. On this account, BLA damage reveals the relative independence of these two routes.…”

The social brain in psychiatric and neurological disorders

“…With the development of more sensitive neuroimaging methods, more subtle changes can now be detected, making the combination of neuroimaging and patient studies particularly fruitful for studying network-level anatomy, functioning, plasticity, and compensation. For instance, morphometric changes in distal cortex following bilateral amygdala lesions have been observed [109], as have structural changes in white matter following damage to the visual cortex (which may account in part for the striking abilities of patients with visual blindsight [110]).…”