Research shows unique dementia profile for those with TBI history

Dementia in people with a history of traumatic brain injury (TBI) may be a clinical phenotype distinct from other known dementia subtypes, according to a study published in the April issue of NeuroRehabilitation.

“As TBI survivors age, the risk of neurodegenerative disorders such as dementia and parkinsonism is a growing concern among patients, caregivers and clinicians,” wrote Kristen Dams-O’Connor, PhD, of the Ichan School of Medicine at Mount Sinai in New York City, and colleagues.

Approximately 10 percent of the U.S. population has sustained a TBI requiring a visit to the hospital, according to the authors. Studies have indicated a possible connection between brain injuries and the development of dementia later in life. Older adults with TBI perform more poorly on measures of attention and verbal memory than non-TBI individuals, and the Institute of Medicine has concluded that moderate and severe TBI is associated with dementia risk.

In an effort to characterize the clinical profiles of dementia patients with a history of TBI, Dams-O’Connor and colleagues conducted a secondary analysis of baseline data from the National Alzheimer’s Coordinating Center Uniform Data Set.

Results showed that, compared with dementia patients who had no TBI history, those with a history of TBI had better cognitive functioning in the areas of immediate and delayed memory and word fluency, reported the authors. The TBI group, though, had worse psychiatric functioning, a slightly higher incidence of clinical depression and worse cardiovascular and cerebrovascular health. Those with TBI also were more likely to have visual hallucinations, gait disorders and other motor functioning issues.

The authors noted that the differences were subtle, and many of the effect sizes were small. Nonetheless, the differences were meaningful in that they suggested poorer overall health and comorbidity in individuals with a history of TBI, underscoring the chronic nature of such injuries.

Dams-O’Connor wrote that the current research is important, because as interventions for Alzheimer’s disease and other conditions are researched, study participants with distinct disease processes may be lumped together, leading to unsuccessful trials. “Failure to consider TBI history in dementia diagnostics may preclude accurate attribution, diagnosis, and treatment of symptoms.”