(HealthDay News) – For individuals with mild cognitive impairment (MCI), but not those with normal cognition, self-reported head trauma involving at least a momentary loss of consciousness is associated with greater amyloid deposition, according to a study published online Dec. 26 in Neurology.

Michelle M. Mielke, PhD, from the Mayo Clinic in Rochester, Minn., and colleagues analyzed the correlation between head trauma and amyloid deposition and neurodegeneration among 448 cognitively normal (CN) individuals and 141 individuals with MCI, from the Mayo Clinic Study of Aging. Participants underwent Pittsburgh compound B-positron emission tomography (PET), fluorodeoxyglucose-PET, and magnetic resonance imaging. Head trauma was defined as a self-reported brain injury with at least momentary loss of consciousness or memory.

The researchers found that 17% of the CN individuals self-reported a head trauma. Neuroimaging measures showed no differences between CN subjects with and without head trauma. Eighteen percent of the participants with MCI self-reported a head trauma, and these participants had significantly higher amyloid levels (by an average 0.36 standardized uptake value ratio units; P=0.002), compared to MCI participants without head trauma.

“Differences between CN individuals and individuals with MCI raise questions about the relevance of head injury-PET abnormality findings in those with MCI,” the authors write.

Several authors disclosed financial ties to the pharmaceutical and health care industries.

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