Research Reports - Traumatic brain injury and age at onset of cognitive impairment in older adults
J Neurol. 2016 Jul;263(7):1280-5. doi: 10.1007/s00415-016-8093-4. Epub 2016 Mar
Li W(1), Risacher SL(2), McAllister TW(3), Saykin AJ(2).
J Neurol. 2016 Jul;263(7):1286.
There is a deficiency of knowledge regarding how traumatic brain injury (TBI) is
associated with age at onset (AAO) of cognitive impairment in older adults.
Participants with a TBI history were identified from the Alzheimer's disease
neuroimaging initiative (ADNI 1/GO/2) medical history database. Using an analysis
of covariance (ANCOVA) model, the AAO was compared between those with and without
TBI, and potential confounding factors were controlled. The AAO was also compared
between those with mild TBI (mTBI) and moderate or severe TBI (sTBI). Lastly, the
effects of mTBI were analyzed on the AAO of participants with clinical diagnoses
of either mild cognitive impairment (MCI) or Alzheimer's disease (AD). The AAO
for a TBI group was 68.2 ± 1.1 years [95 % confidence interval (CI) 66.2-70.3,
n = 62], which was significantly earlier than the AAO for the non-TBI group of
70.9 ± 0.2 years (95 % CI 70.5-71.4, n = 1197) (p = 0.013). Participants with
mTBI history showed an AAO of 68.5 ± 1.1 years (n = 56), which was significantly
earlier than the AAO for the non-TBI group (p = 0.032). Participants with both
MCI and mTBI showed an AAO of 66.5 ± 1.3 years (95 % CI 63.9-69.1, n = 45),
compared to 70.6 ± 0.3 years for the non-TBI MCI group (95 % CI 70.1-71.1,
n = 935) (p = 0.016). As a conclusion, a history of TBI may accelerate the AAO of
cognitive impairment by two or more years. These results were consistent with
reports of TBI as a significant risk factor for cognitive decline in older
adults, and TBI is associated with an earlier AAO found in patients with MCI or