Episodic memory deficits are associated with impaired insight in traumatic encephalopathy syndrome: Initial findings of the SNAP-CTE study

Abstract

Chronic traumatic encephalopathy (CTE) has been identified at post-mortem in Australian football codes players. Detailed and objective clinical and radiological characterization of patients at-risk of sporting and non-sporting repetitive concussive and subconcussive traumatic brain injury (RC/SCI) is important to our understanding of traumatic encephalopathy syndrome (TES) and CTE. This paper presents the initial findings of the symptomatology, neurocognitive, and pathophysiological changes in CTE (SNAP-CTE) study. A preliminary, retrospective, cohort study of 28 patients (25 males and 3 females) presenting with complaints of mood, behavioral, and cognitive decline, comprising TES, aged 24 to 78 years (M = 53, SD = 15.3) with at least 10 years of exposure to RC/SCI (mostly through contact sport) and cognitive decline were examined including: demographics; duration of play; age of first exposure to RC/SCI; and neuropsychology. Participants performed significantly worse in tests of auditory, visual, immediate, and delayed memory compared to a normative sample. Those with absent insight, compared to those with preserved insight, had a larger discrepancy between predicted and actual auditory memory scores, and had more severe mood disturbances. Insight, a hallmark sign of dementia, was either absent or impaired in a significant proportion (M = 36.4%, 95% CI =17.2% - 59.3%) of the sample aged under 65, compared with normative epidemiological data. This indicates that RC/SCI may be associated with risk of an early onset dementia syndrome representing probably TES/CTE. CTE is increasingly of concern to the Australian community, and further research in this area is necessary. This retrospective preliminary study will form the basis of large, prospective, longitudinal cohort studies, assessing the natural history of TES/CTE in Australian athletes.