Neuroanatomical basis of paroxysmal sympathetic hyperactivity: A diffusion tensor imaging analysis

Abstract

Primary objective: Paroxysmal sympathetic hyperactivity (PSH) is observed in a sub-set of patients with moderate-to-severe traumatic brain injury (TBI). The neuroanatomical basis of PSH is poorly understood. It is hypothesized that PSH is linked to changes in connectivity within the central autonomic network.

Research design: Retrospective analysis in a sub-set of patients from a multi-centre, prospective cohort study

Methods and procedures: Adult patients who were <3 weeks after severe TBI were enrolled and screened for PSH using a standard definition. Patients underwent multimodal MRI, which included quantitative diffusion tensor imaging.

Main outcomes and results: Principal component analysis (PCA) was used to resolve the set of tracts into components. Ability to predict PSH was evaluated via area under the receiver operating characteristic (AUROC) and tree-based classification analyses. Among 102 enrolled patients, 16 met criteria for PSH. The first principle component was significantly associated (p = 0.024, AUROC = 0.867) with PSH status even after controlling for age and admission GCS. In a classification tree analysis, age, GCS and decreased FA in the splenium of the corpus callosum and in the right posterior limb of the internal capsule discriminated PSH vs no PSH with an AUROC of 0.933.

Conclusions: Disconnection involving the posterior corpus callosum and of the posterior limb of the internal capsule may play a role in the pathogenesis or expression of PSH.

• Diffusion tensor imaging
• paroxysmal sympathetic hyperactivity
• traumatic brain injury

Acknowledgements

The project described was supported in part by Award Number 5K12HL108974-03 from the National Heart, Lung, and Blood Institute. This publication was supported by Oregon Clinical and Translational Research Institute (OCTRI), grant number (UL1TR000128) from the National Center for Advancing Translational Sciences (NCATS) at the National Institutes of Health (NIH).

Declaration of interest

The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Heart, Lung and Blood Institute or the National Institutes of Health. This research was also supported by ‘Investissements d’avenir’ ANR-10-IAIHU-06. The authors report no conflicts of interest.