Researchers have found that individuals with spinal cord injury and older healthy individuals have similar brain activation during processing speed tasks, supporting the theory that accelerated cognitive aging can occur after spinal cord injury.
The team of Kessler Foundation rehabilitation researchers examined processing speed deficits and compared the brain activation patterns of individuals with spinal cord injuries (SCIs) with those of healthy age-matched controls. They found that the SCI group and older controls had similar activation patterns, but the SCI group and the age-matched controls had significant differences.
According to a press release, individuals with chronic SCI have an increased risk for cognitive deficits that resemble the deficits associated with the aging process, in a theory called “accelerated cognitive aging.” The team had previously found that these deficits affect processing speed, new learning and memory, and verbal fluency, which are the same areas affected during aging.
Their new research is the first study to examine the neural mechanisms of higher-order cognitive tasks of individuals with SCI. The investigators focused on processing speed, which is known to be affected by SCI and aging and is integral to cognitive function and everyday life activities.
The 30 study participants were part of a larger study of individuals who underwent optional neuroimaging studies at the Rocco Ortenzio Neuroimaging Center at the Kessler Foundation. There were 10 individuals with cervical SCI, 10 age-matched controls, and 10 healthy older individuals. The participants underwent traditional neuropsychological testing methods and processing speed was tested using timed letter comparison tasks during functional magnetic resonance imaging (fMRI).
The researchers found significant differences in brain activation between the SCI group and the age-matched control group; however, the SCI and older groups had similar patterns, including activation of the hippocampal, frontal, and parietal areas.
“This suggests that individuals with SCI are compensating for deficits in processing speed by relying on the areas of the brain involved in executive control and memory, which supports the theory of accelerated brain aging after SCI,” said researcher Nancy Chiaravalloti, Ph.D., in a press release.
The authors did note limitations, such as sample size and level of injury, but said their research is an important contribution to understanding the impact of SCI on cognition.
“Our ability to observe brain activation while the individual performs specific cognitive tasks provides new information on the mechanisms that underlie the cognitive deficits that we now know affect a substantial proportion of the SCI population,” said Glenn Wylie, Ph.D., in a press release. “Developing treatments targeted to these deficits depends on our pursuit of this line of research, which may benefit other populations affected by delayed processing speed.”