Results support the hypothesis of cognitive reserve in traumatic brain injury

Kessler Foundation researchers have found that higher educational attainment (a proxy of intellectual enrichment) attenuates the negative impact of  traumatic brain injury (TBI) on cognitive status. The brief report, Sumowski J, Chiaravalloti N, Krch D, Paxton J, DeLuca J. Education attenuates the negative impact of traumatic brain injury (TBI) on cognitive status, was published in the December issue of Archives of Physical Medicine & Rehabilitation. 

Cognitive outcomes vary post-TBI, even among individuals with comparable injuries. To examine this finding, investigators looked at whether the hypothesis of cognitive reserve helps to explain this differential cognitive impairment following TBI.  Kessler Foundation investigators have previously supported the cognitive reserve hypothesis in persons with multiple sclerosis, demonstrating that lifetime intellectual enrichment protects patients from cognitive impairment (for review, Sumowski & Leavitt. Cognitive reserve in multiple sclerosis. Multiple Sclerosis Journal 2013; 19: 1122-27. In the current study, they sought to determine whether individuals with TBI with greater intellectual enrichment pre-injury (estimated with education), are less vulnerable to cognitive impairment.

Researchers compared 44 people with moderate to severe TBI with 36 healthy controls. Their cognitive status (processing speed, working memory, episodic memory) was evaluated with neuropsychological tasks. “Although cognitive status was worse in the TBI group,” said Dr. Sumowski, senior research scientist in Neuropsychology & Neuroscience Research at Kessler Foundation, “higher education attenuated the negative effect of TBI on cognitive status, such that persons with higher education were protected against TBI-related cognitive impairment.”

“These results support the hypothesis of cognitive reserve in TBI, ie, as in MS, higher intellectual enrichment benefits cognitive status,” concluded Dr. Chiaravalloti, the Foundation’s director of TBI Research. “This knowledge may help identify those persons with TBI who need early intervention because they are at greater risk for cognitive impairment.  It may be beneficial to encourage enriching activities among those with TBI,” she added. “Although causation has not been proved, intellectually enriching activities may protect against further cognitive decline.”