Networks underlying trait impulsivity: Evidence from voxel-based lesion-symptom mapping

Abstract

Impulsivity is considered a multidimensional construct that encompasses a range of behaviors, including poor impulse control, premature decision-making, and the inability to delay gratification. In order to determine the extent to which impulsivity and its components share a common network, we performed a voxel-based lesion-symptom mapping (VLSM) analysis in a large sample of patients (N=131) with focal, penetrating traumatic brain injuries (pTBI). Impulsivity was assessed using the Barratt Impulsiveness Scale (BIS-11), a standard self-report measure that allows for unique estimates of global impulsivity and its factor analysis-derived components (e.g., “motor impulsivity”). Heightened global impulsivity was associated with damage to multiple areas in bilateral prefrontal cortex (PFC), left superior, middle and inferior temporal gyrus, and left hippocampus. Moreover, we identified a cluster within the left PFC associated specifically with motor impulsivity (defined as “acting without thinking”). Our results are consistent with existing literature on bilateral prefrontal cortical involvement in behavioral impulsivity, but also provide new evidence for a more complex neuroanatomical representation of this construct, characterized by left-lateralized temporal and hippocampal involvement, as well as a left-lateralized prefrontal network specifically associated with motor impulsivity.

Lesion Topography Impact on Shoulder Abduction and Finger Extension Following Left and Right Hemispheric Stroke

“…Voxel-by-voxel analysis was used to calculate the statistical significance of performance difference between subjects with and without damage in a given voxel, using the Mann-Whitney test. To avoid spurious results due to low numbers of lesioned voxels, only voxels lesioned in at least 10 subjects were tested (Rorden et al, 2007 ; Medina et al, 2010 ; Handelzalts et al, 2019 ) and at least 10 adjacent voxels had to show a statistically significant impact on performance for a cluster of voxels to be reported (McDonald et al, 2017 ). To correct for multiple comparisons, voxels with values exceeding a permutation threshold of p < 0.05 were considered significant (Mirman et al, 2018 ).…”

Traumatic brain injury and methamphetamine: A double-hit neurological insult

“…Users also display a dysfunctional orbitofrontal cortex [59,60] and a smaller hippocampal size [56] with a maintained reduction in its volume in recent female abstinent users [61]. On the TBI front, recent studies have observed that focal penetrating injuries to the PFC lead to executive dysfunction and marked impulsivity, two traits implicated in addiction [62,63]. Also, high-level cognitive functions that regulate impulsivity, such as response inhibition, are compromised in diffuse axonal injury [64], a key feature of pathology seen following TBI [65,66].…”

Factors affecting increased risk for substance use disorders following traumatic brain injury: What we can learn from animal models

“…Notably, focal (i.e. penetrating) injuries to the PFC are associated with important behavioral deficits, as studies by Cristofori et al and McDonald et al have shown that damage to the PFC produces executive dysfunction and heightened impulsivity, two traits commonly implicated in drug and alcohol dependence 33, 34 . Therefore, regardless of TBI severity, damage to the PFC may be an important factor affecting the risk of SUDs in patients with a history of TBI.…”