Effect of traumatic brain injury on mild behavioral impairment domains prior to all‐cause dementia diagnosis and throughout disease progression

Abstract

Introduction Traumatic brain injury (TBI) may alter dementia progression, although co‐occurring neuropsychiatric symptoms (NPS) have received less attention. Originally designed to evaluate behavioral disruption prior to dementia diagnosis, the mild behavioral impairment (MBI) construct relates NPS to underlying neural circuit disruptions, with probable relevance across the progression of neurodegenerative disease. Therefore, the MBI construct may represent a valuable tool to identify and evaluate related NPS both preceding diagnosis of all‐cause dementia throughout the progression of disease, representing an important area of inquiry regarding TBI and dementia. This investigation sought to evaluate the effect of TBI on NPS related by the MBI construct in participants progressing from normal cognitive status to all‐cause dementia. Methods Using National Alzheimer's Coordinating Center data, individuals progressing from normal cognition to all‐cause dementia (clinician diagnosed) over 7.6 ± 3.0 years were studied to estimate prevalence of MBI domains in 124 participants with prior TBI history (57 with loss of consciousness [LOC] <5 minutes, 22 with LOC >5 min, 45 unknown severity) compared to 822 without. MBI domain prevalence was evaluated (1) prior to dementia onset (including only time points preceding time at dementia diagnosis, as per MBI's original definition) and (2) throughout dementia progression (evaluating all available time points, including both before and after dementia diagnosis). Results More severe TBI (LOC >5 minutes) was associated with the social inappropriateness MBI domain (adjusted odds ratio = 4.034; P = 0.024) prior to dementia onset, and the abnormal perception/thought content domain looking across dementia progression (adjusted hazard ratio [HR adj ] = 3.703; P = 0.005). TBI (all severities) was associated with the decreased motivation domain looking throughout dementia progression (HR adj. = 1.546; P = 0.014). Discussion TBI history is associated with particular MBI profiles prior to onset and throughout progression of dementia. Understanding TBI's impact on inter‐related NPS may help elucidate underlying neuropathology with implications for surveillance, detection, and treatment of behavioral concerns in aging TBI survivors. Highlights The mild behavioral impairment (MBI) construct links related neuropsychiatric symptoms (NPS) by probable underlying neural network dysfunction. Traumatic brain injury (TBI) with loss of consciousness (LOC) > 5 minutes was associated with pre‐dementia social inappropriateness. TBI was associated with decreased motivation looking across dementia progression. TBI with LOC > 5 minutes was associated with abn...

Associations of Prior Head Injury With Mild Behavioral Impairment Domains

“…In a hospital-based sample, the prevalence of acute/subacute posthead injury aggression has been estimated to be 28.4%, and is often associated with new-onset major depression 29. Additionally, it has been found that sustaining a head injury before onset of dementia leads to higher rates of irritability, disinhibition, and motor disorders compared with no head injury history 6,30–32. In terms of sex differences, this study found that associations of head injury status with impairment in the impulse dyscontrol domain were stronger among females than among males.…”

“…29 Additionally, it has been found that sustaining a head injury before onset of dementia leads to higher rates of irritability, disinhibition, and motor disorders compared with no head injury history. 6,[30][31][32] In terms of sex differences, this study found that associations of head injury status with impairment in the impulse dyscontrol domain were stronger among females than among males. This is consistent with a prior study from the subacute period after head injury, which found that women were more vulnerable than men to persistent mild head injuryrelated cognitive and somatic symptoms.…”

Association of Neuropsychiatric Symptom Profiles With Cognitive Decline in Patients With Parkinson Disease and Mild Cognitive Impairment

“…The consensus criteria for MBI include 5 domains, including motivation, affective regulation, impulse control, social cognition, and perception/thought, 25 and the utility of MBI has been investigated in various neurodegenerative diseases. 8,26,27 Confirmatory analyses, such as MBI construct, have the advantage of being able to explain underlying neurobiology based on previous studies. By contrast, exploratory factor analyses, as conducted in our study, are primarily data driven.…”