J Head Trauma Rehabil Vol. 29, No. 2, pp. 172–184 Copyright c  2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Assessing Aggression Following Traumatic Brain Injury: A Systematic Review of Validated Aggression Scales Michael D. Cusimano, MD, PhD, FRCSC, FACS; Scott A. Holmes, MSc; Carolyn Sawicki, BSc; Jane Topolovec-Vranic, PhD Background: Every year, millions of people worldwide suffer traumatic brain injuries (TBIs). Aggressive behavior, a known psychological symptom following TBI, has been regarded as an obstacle toward rehabilitation. Having measures that accurately assess aggression during rehabilitation is critical toward proper evaluation. Objective: To undertake a systematic review of the validated scales used to assess aggression in the postacute stage (≥3 months) after sustaining a TBI in the adult population. A comprehensive search was performed and studies meeting the inclusion criteria were reviewed in full. Quality and validity of supporting articles were assessed via the Downs and Black and QUADAS checklists along with their supporting statistics. Results: A total of 1329 articles were reviewed from the literature. Thirty-two were reviewed in detail and 6 studies eventually passed the exclusion criteria. Of these, 6 neuropsychological scales were represented pertaining to the measurement of aggressive behavior; however, only 1 directly addressed the validity of their scale’s aggression component. Conclusions: Further research is required to establish the validity of scales that specifically address aggression for use in the adult TBI population which could be used to support rehabilitation and social reintegration strategies. Key words: adult, aggression, assessment tools, neuropsychology, systematic review, traumatic brain injury T HE INCIDENCE OF TRAUMATIC BRAIN INJURY (TBI) occurs at more than 8 times that of breast cancer and more than 30 times that of hu- man immunodeficiency virus. 1–3 Data from the United States show that although there are 1.7 million individ- ual cases of TBI annually, deaths have decreased in the last 30 years to approximately 53 000 persons annually, shifting some attention to the chronic management of Author Affiliations: Injury Prevention Research Office, Li Ka Shing Knowledge Institute, Keenan Research Centre, Division of Neurosurgery, St Michael’s Hospital, University of Toronto, Toronto, Ontario, Canada (Dr Cusimano); Department of Neurology and Neurosurgery, McGill University; Montreal, Quebec, Canada (Mr Holmes); University of Western Ontario; London, Ontario, Canada (Ms Sawicki); and Li Ka Shing Knowledge Institute, Trauma and Neurosurgery Program and Keenan Research Centre, St Michael’s Hospital, Toronto, Ontario (Dr Topolovec-Vranic), Canada. The authors represent the Canadian Brain Injury and Violence Research Team. This research was supported by the Canadian Institutes of Health Research Strategic Team Grant in Applied Injury Research #TIR-103946 and funding from the Ontario Neurotrauma Foundation and St Michael’s Hospital Foundation. The authors decalre no conflicts of interest. Corresponding Author: Michael D. Cusimano, MD, PhD, FRCSC, FACS, Injury Prevention Research Office, Li Ka Shing Knowledge Institute, Keenan Research Centre, Division of Neurosurgery, St Michael’s Hospital, University of Toronto, 30 Bond St, Toronto, ON, Canada, M5B 1W8 (injurypreven- tion@smh.toronto.on.ca). DOI: 10.1097/HTR.0b013e31827c7d15 symptoms from a sole focus on acute management. 3–5 Recent research has begun to shed light on the often overlooked role of psychological distress post-TBI that is routinely shadowed from the overt physical symptoms associated with the injury. The psychological symptoms experienced post-TBI can range from problems includ- ing maintaining attention to more debilitating concerns such as depression; however, few symptoms are as de- structive to both personal and social rehabilitation as ag- gression. Past studies highlight the fact that although ag- gressive behavior is not the most common symptom, oc- curring in approximately 30% of TBI cases, it is severely destructive to both the individual and their social net- works, and has even been implicated as both a causative and resulting agent to the occurrence of a TBI. 6–10 The neurological insult of a TBI may predispose an individual to behavioral changes including aggression. Anatomically, the frontal and temporal lobes are par- ticularly susceptible to damage due to their proximity to bony structures at the base of the skull. 11,12 Damage to the orbitofrontal area has been shown to impair the ability to regulate impulsive behaviors and commonly results in the disinhibition of aggression, whereas injury to the temporal lobes has been associated with changes in emotional behavior, particularly with poorly directed outbursts of anger. 12–17 Indeed, the appearance of ag- gressive behaviors postinjury may not be the result of Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. 172