Visuospatial memory improvement in patients with diffuse axonal injury (DAI): a 1-year follow-up study

Diffuse axonal injury (DAI) is prevalent in traumatic brain injury (TBI), and is often associated with poor outcomes and cognitive impairment, including memory deficits. Few studies have explored visual memory after TBI and its relationship to executive functioning. Executive functioning is crucial for remembering an object's location, operating devices, driving, and route finding. We compared visual memory performance via the Rey-Osterrieth Complex Figure (ROCF) test 6 and 12 months after DAI.

In total, 40 patients (mean age 28.7 years; 87.5% male) with moderate-to-severe DAI following a road traffic accident completed the 1-year follow-up. There was a three-phase prospective assessment. In phase 1 (1-3 months after trauma), patients completed the Beck Depression Inventory (BDI) and State-Trait Anxiety Inventory (STAI). In phases 2 (6 months) and 3 (12 months), they completed the BDI, STAI, and a neuropsychological battery [ROCF copy and recall, digit span forward/backward, Grooved Pegboard test, intelligence quotient (IQ) by Wechsler Adult Intelligence Scale-III (WAIS-III)].

There was an improvement in ROCF recall over time (p=0.013), but not ROCF copy (p=0.657).There was no change in executive function (Savage scores) copy (p=0.230) or recall (p=0.155). Age, years of education, severity of the trauma, and IQ did not influence ROCF recall improvement.

There are time-dependent improvements in visual memory in patients with DAI. Neuroplasticity in the 1st months after trauma provides an opportunity for visuospatial memory learning. The present findings may be useful to formulate management plans for long-term TBI rehabilitation.