Traumatic brain injury (TBI) and several neurological conditions appear to be linked in both directions among older adults, a study of US veterans suggests.
Veterans who sustained a TBI had higher rates of stroke, dementia, Parkinson’s disease and epilepsy before the injury than participants without TBI.
After TBI, rates of stroke, epilepsy and dementia increased significantly, while the rate of Parkinson’s disease did not.
The findings suggest that the period after someone is diagnosed with a neurological condition may be particularly important for preventing head injuries.
Researcher Carrie Peltz said: “These findings suggest that the period after being diagnosed with a neurological condition is an important time period for preventing TBI.
“Our findings raise the possibility that dementia, stroke, epilepsy and Parkinson’s disease are themselves risk factors for TBI in older people.
“Neurological diseases often impair motor control, balance, gait, coordination and thinking skills, all of which make people more likely to fall, which is the main cause of TBI in older adults.”
Researchers from the Northern California Institute for Research and Education examined veterans aged 55 and older who received care at US Veterans Health Affairs facilities.
The retrospective cohort study, which analysed previously collected information, included 13,801 veterans with an acute traumatic brain injury and 41,403 matched participants without TBI.
Traumatic brain injury, or TBI, is damage to the brain caused by an external force, such as a fall, collision or blow to the head.
The team identified new cases of stroke, Parkinson’s disease, epilepsy and dementia during the year before and after TBI.
Rates among participants without TBI were assessed over a corresponding two-year period.
Before their injuries, the incidence rate of stroke among veterans in the TBI group was 3.2 times that recorded among participants without TBI.
The incidence rate was also 3.1 times higher for dementia, three times higher for Parkinson’s disease and 4.4 times higher for epilepsy.
The associations became slightly weaker after researchers accounted for other health conditions and differences in healthcare use, but remained significant.
Among veterans with TBI, incidence rates of stroke, epilepsy and dementia were significantly higher during the year after the injury than during the preceding year.
The incidence rate of stroke was 1.83 times that recorded before TBI. The corresponding rates were 2.29 times higher for epilepsy and 1.24 times higher for dementia.
The incidence rate of Parkinson’s disease did not differ significantly between the periods before and after TBI.
