Neural underpinnings of the slowness of information processing in patients with traumatic brain injury: insights from tract-based spatial statistics.

Slowness of information processing (SIP) is frequently reported after traumatic brain injury (TBI). Previous studies point toward a pivotal role of white matter damage on speed of information processing. However, little is known about the more comprehensive and ecological assessment of SIP in TBI. Here, we combined an ecological assessment of SIP with the use of tract-based spatial statistics (TBSS) on individuals' fractional anisotropy (FA) maps. Twenty-six moderate-to-severe patients with TBI (21 males and 5 females) participated in this study: 10 individuals were classified as not having SIP (SIP-) and 16 were classified as having SIP (SIP +). SIP + showed lower FA in bilateral anterior thalamic radiation, corticospinal tract, cingulum, and forceps, as well as in bilateral inferior fronto-occipital, inferior and superior longitudinal fasciculi and uncinate fasciculus. Overall, this result is consistent with and expands previous reports on information processing speed to a more comprehensive and ecological perspective on SIP in TBI.

Two Ecological Tools for Testing Slowness of Information Processing in Italian Patients with Moderate-to-Severe Traumatic Brain Injury.

Slowness of Information Processing (SIP) is frequently experienced after traumatic brain injury (TBI); however, the impact of SIP on everyday functioning may be underestimated by standard neuropsychological tests. OBJECTIVE: we aimed to adapt two ecological instruments assessing SIP in Italian patients with moderate-to-severe TBI, as formerly proposed by Winkens and colleagues for persons with stroke, testing also its possible relation with other neuropsychological processes and functional outcomes. METHOD: we performed an observational study on 37 patients with moderate-to-severe TBI and 35 demographically matched healthy controls, who underwent the Mental Slowness Observation Test (MSOT) and the Mental Slowness Questionnaire (MSQ), which had been adapted through a pilot study on independent sample of participants; extensive neuropsychological and functional evaluations were performed as well. RESULTS: We found good clinical and psychometric properties of the Italian adaptation of the MSOT and MSQ; also, performance on MSOT significantly correlated with executive functions. Moreover, patients with TBI are significantly slower and less accurate than healthy controls on the MSOT, in particular in tasks with time limits. Even if the subjective feeling of SIP does not differ between patients and controls, we found a significant correlation between MSQ and MSOT. Finally, the performances on the MSOT correlated with measures of functional outcome and community integration. CONCLUSIONS: the results support the use of the MSOT and the MSQ to measure SIP in an ecological fashion in patients with TBI, so that specific treatments for persons with acquired brain injury can be prescribed.