Cognitive and behavioural post-traumatic impairments: what is the specificity of a brain injury ? A study within the...

The variety and extent of impairments occurring after traumatic brain injury vary according to the nature and severity of the lesions. In order to better understand their interactions and long-term outcome, we have studied and compared the cognitive and neurobehavioral profile one year post onset of patients with and without traumatic brain injury in a cohort of motor vehicle accident victims.

The study population is composed of 207 seriously injured persons from the ESPARR cohort. This cohort, which has been followed up in time, consists in 1168 motor vehicle accident victims (aged 16 years or more) with injuries with all degrees of severity. Inclusion criteria were: living in Rhone county, victim of a traffic accident having involved at least one wheel-conducted vehicle and having occurred in Rhone county, alive at the time of arrival in hospital and having presented in one of the different ER facilities of the county. The cohort's representativeness regarding social and geographic criteria and the specificities of the accidents were ensured by the specific targeting of recruitment. Deficits and impairments were assessed one year after the accident using the Neurobehavioral Rating Scale - Revised and the Trail-Making Test. Within our seriously injured group, based on the Glasgow Score, the presence of neurological deficits, aggravation of neurological condition in the first 72hours and/or abnormal cerebral imaging, we identified three categories: (i) moderate/severe traumatic brain injury (n=48), (ii) mild traumatic brain injury (n=89), and (iii) severely injured but without traumatic brain injury (n=70).

The most frequently observed symptoms were anxiety, irritability, memory and attention impairments, depressive mood and emotional lability. While depressive mood and irritability were observed with similar frequency in all three groups, memory and attention impairments, anxiety and reduced initiative were more specific to traumatic brain injury whereas executive disorders were associated with moderate/severe traumatic brain injury.

The presence and the initial severity of a traumatic brain injury condition the nature and frequency of residual effects after one year. Some impairments such as irritability, which is generally associated with traumatic brain injury, do not appear to be specific to this population, nor does depressive mood. Substantial interactions between cognitive, affective and neurobehavioral disorders have been highlighted.