Traumatic brain injury alters neuropsychiatric symptomatology in all-cause dementia

Abstract

Introduction: Traumatic brain injury (TBI) may alter the course of neuropsychiatric symptom (NPS) onset during dementia development. The connection among TBI, NPS, and dementia progression is of increasing interest to researchers and clinicians.

Methods: Incidence of NPS was examined in participants with normal cognition who progressed to all-cause dementia based on whether TBI history was present (n = 130) or absent (n = 849). Survival analyses were used to examine NPS incidence across 7.6 ± 3.0 years of follow-up.

Results: Participants with TBI history had increased prevalence and incidence of apathy (44.7% vs 29.9%, P = .0062; HR_adj. = 1.708, P = .0018) and motor disturbances (17.2% vs 9.5%, P = .0458; HR_adj. = 2.023, P = .0168), controlling for demographics and type of dementia diagnosis. Earlier anxiety onset was associated with TBI (692 days prior to dementia diagnosis vs 161 days, P = .0265).

Discussion: History of TBI is associated with increased risk for and earlier onset of NPS in the trajectory of dementia development.

Keywords: Alzheimer's disease; acquired brain injury; all-cause dementia; anxiety; apathy; dementia; geriatric psychiatry; mild behavioral impairment; motor disturbances; neurodegeneration; neuropsychiatric symptoms; neuropsychiatry; traumatic brain injury.

Figure 1:

Cumulative incidence plots (Kaplan-Meier method) illustrating symptom development for participants with (teal) and without (orange) history of traumatic brain injury (TBI), relative to time at dementia diagnosis (time = 0, dashed line). X-axis represents days relative to dementia diagnosis with negative values indicating incidence prior to diagnosis. Cumulative incidence is reported for MCI (A), any NPS (B), agitation (C), anxiety (D), apathy (E), delusions (F), depression (G), disinhibiton (H), elation (I), hallucinations (J), irritability (K), and motor disturbances (L). **: P < .01; *: P < .05. ns, not significant; MCI, mild cognitive impairment; NPS, neuropsychiatric symptoms (any)

Figure 2:

Violin plots illustrating time at symptom onset for participants with (teal) and without (orange) history of traumatic brain injury (TBI), relative to time at dementia diagnosis (time = 0, dashed line). Time at onset of symptoms is reported for MCI (A), any NPS (B), agitation (C), anxiety (D), apathy (E), delusions (F), depression (G), disinhibiton (H), elation (I), hallucinations (J), irritability (K), and motor disturbances (L). *: P < .05. ns, Not significant; MCI, mild cognitive impairment; NPS, neuropsychiatric symptoms (any)