Permanent post-concussion symptoms after mild head injury

OBJECTIVE: A small minority of individuals experience long-term or permanent post-concussion symptoms (PCS) after a mild head injury (MHI). There has been no systematic, quantitative research examining a wide range of variables in a representative sample of such patients (i.e. with PCS for more than 18 months). This study explores a broad spectrum of demographic, cognitive, emotional and psychosocial factors (known to be important in the development of early PCS) in a representative sample of patients with permanent PCS. METHOD: One hundred consecutively referred patients to a Community Head Injury Service in Buckinghamshire, UK for the treatment of persistent PCS, at least 18 months post-MHI, were identified and invited to participate. An exploratory design evaluated a range of demographic, cognitive, emotional and psychosocial variables and their relationship to PCS severity and quality-of-life (QoL). RESULTS: Twenty-four participants, with a mean time post-injury of 6.9 years, responded. They were characterized by: (i) older age compared to those typically presenting with MHI, (ii) very high levels of PCS, (iii) high post-injury unemployment, (iv) pre- or post-morbid factors which might exacerbate post-concussional difficulties, (v) elevated levels of anxiety and depression and (vi) mildly reduced scores on tests of short-term memory and speed of information processing. Post-hoc analysis of the total sample (n = 100) confirmed older age and a high proportion having pre- or post-morbid factors. QoL negatively correlated with PCS severity, and anxiety scores accounted for 45.9% of the variance in PCS severity. CONCLUSIONS: Very high levels of PCS, high post-injury unemployment and measurable cognitive deficits can be permanent features of MHI. Quality-of-life is directly related to symptom severity. Age, pre-/post-morbid concomitant factors, neuropsychological deficits and emotional status are key variables in understanding the phenomenon of permanent PCS. Important vulnerability factors in the development of such may therefore be older age and any additional compromise to an individual's emotional or cognitive capacities.