Critical role of the right uncinate fasciculus in emotional empathy

Abstract

Objective: Common neurological diseases or injuries that can affect the right hemisphere, including stroke, traumatic brain injury, and frontotemporal dementia, disrupt emotional empathy-the ability to share in and make inferences about how other people feel. This impairment negatively impacts social interactions and relationships. Accumulating evidence indicates that emotional empathy depends on coordinated functions of orbitofrontal cortex, anterior insula, anterior cingulate, temporal pole, and amygdala, but few studies have investigated effects of lesions to white matter tracts that connect these structures. We tested the hypothesis that percentage damage to specific white matter tracts connecting these gray matter structures predicts error rate in an emotional empathy task after acute right hemisphere ischemic stroke. Methods: We used multivariate linear regression with percentage damage to 8 white matter tracts, age, and education as independent variables and error rate on emotional empathy as the dependent variable to test a predictive model of emotional empathy in 30 patients with acute ischemic right hemisphere stroke. Results: Percentage damage to 8 white matter tracts along with age and education predicted the error rate in emotional empathy, but only percentage damage to the uncinate fasciculus was independently associated with error rate. Participants with right uncinate fasciculus lesions were significantly more impaired than right hemisphere stroke patients without uncinate fasciculus lesions in the emotional empathy task. Interpretation: The right uncinate fasciculus plays an important role in the emotional empathy network. Patients with lesions in this network should be evaluated for empathy, so that deficits can be addressed. ANN NEUROL 2015;77:68-74 A coherent hypothesis about the neural network underlying emotional empathy has emerged from various sources: functional magnetic resonance imaging (MRI) of healthy individuals experiencing empathy, 1-7 resting state functional connectivity studies of individuals with frontotemporal dementia (who have impaired empathy), 8 focal lesion studies, 9-11 and voxel-based morphometry studies 12,13 of individuals with impaired empathy. Together, these studies have identified the important roles of several cortical and limbic areas, including prefrontal cortex, orbitofrontal cortex, amygdala, and temporal pole, particularly in the right hemisphere. Some of components of this network may be especially critical for specific processes underlying emotional empathy. 14-24 These areas are strongly interconnected with the anterior insula and anterior cingulate cortex, 1,25,26 areas that themselves are clearly engaged when healthy people empathize with others. 1,2,4-7 Seeley and colleagues 8 have raised the possibility that Von Economo neurons, found in anterior cingulate and anterior insula, are selectively targeted in behavioral variant frontotemporal dementia (bvFTD), a neurodegenerative disease in which impaired empathy is prominent feature. Loss of Von Econo...

Cognitive Function and White Matter Changes Associated with Renal Transplantation

“…The corticospinal tracts have not been reported to have a specific role in memory or executive function and control voluntary movement. The uncinate fasciculus control emotions[34]. The degree of change in DTI metrics were consistent with the degree of improvement seen in some other medical conditions[22, 35].…”

A disconnection account of subjective empathy impairments in diffuse low-grade glioma patients

“…In this study, we have focused our investigation on the connectional anatomy of the subjective empathy network with the rationale that only one lesion study (Oishi et al, 2015) have to date rely empathy functioning to white matter connectivity. To shed light on this matter, we processed self-reports of empathy, obtained from a large group of homogenous glioma patients, by combining voxelwise and tractwise analyses.…”

“…In a population of schizophrenic patients, certain dimensions of empathy as indexed by the interpersonal reactivity index (IRI; Davis, 1983) were shown to differentially correlate with FA measurements in white matter fibres belonging to the left inferior fronto-occipital fasciculus and the splenium of the corpus callosum (Fujino et al, 2014). Remarkably, a causal link was found between damage to the right uncinate fasciculus and emotional empathy in a sample of 30 patients with stroke injury in a very recent study (Oishi et al, 2015). Aside from these studies, the relationships between disturbance in empathic functioning and damage to white matter connectivity has not been yet explored in a large-scale neuropsychological population.…”

Multidimensional assessment of empathic abilities in patients with insular glioma

“…Prominent subcortical fiber bundles, including the uncinate and the arcuate fascicle, connect the insula to the frontoorbital and temporopolar and temporomesial regions. Damage to the opercula or fiber might have impacted the performance on empathy scales in some patients (Martino et al, 2015;Oishi et al, 2015). Furthermore, a larger sample size would have allowed for comparisons according to the particular location of the insular-cortex lesions (anterior vs. posterior insular cortex), which could be of special interest given the functional segregation within the insular cortex revealed by functional imaging and intracerebral electrical stimulation studies (Kurth, Zilles, Fox, Laird, & Eickhoff, 2010).…”