Introduction Injury Severity Score (ISS) and GCS can be retrospective markers of injury severity, but if used by clinicians to decide on the treatment of acutely brain-injured casualties at the point of injury may potentially limit interventions on people who may ultimately survive with good functional outcomes.

Methods ISS/GCS and long-term outcomes were reviewed by assessing all UK military neurorehabilitation patients with an operational/combat brain injury treated over 4 years (February 2008–July 2012) at Defence Medical Rehabilitation Centre (Headley Court).

Results 34 participants from 9 operational tours of Iraq and Afghanistan were analysed. Overall, 44% of injuries were due to improvised explosive devices (IEDs) and 41% from gunshot wounds; 70.9% of injuries were penetrating wounds with the remainder due to blast/blunt trauma or combined injury. The primary injury was head/neck in 76.5%, although eight patients (23.4%) requiring neurorehabilitation were initially ‘non-head injury’. Eight patients (26.5%) sustained more than 10 injuries, and 18 had between three and nine injuries. Eleven patients (32%) had an initial GCS of 3, and 16 (47%) had ISS of 75 (deemed ‘unsurvivable’). All patients with ISS of 75 were long-term survivors. At 4 months after discharge, 47% (16) were fully independent, and a further 41% (14) were independent in own homes, but needed assistance with some activities, such as paying bills. Over three-quarters (27 patients, 79%) returned to full/part-time work, 11 of whom returned to military duties; 93% of ‘unsurvivable’ ISS, and 91% of patients with GCS of 3 were capable of returning/returned to work. In total, 7/11 casualties returning to military duties had major trauma ISS, and two were ‘unsurvivable’. All seven casualties with both GCS 3 and ISS 75 survived and returned to independence (help with some activities).

Conclusions ISS/GCS at the point of injury does not reflect eventual outcome. IEDs/gunshots cause the greatest number of injuries and the highest incidence of brain injury. Brain injury should be considered in every battlefield casualty, irrespective of whether the head/neck/spinal cord was avoided. ISS should not be considered indicative or predictive of long-term prognosis/quality of life/employability as brain injury in this small cohort is both survivable and recoverable. It should not be used as a retrospective guide to alter treatment pathways, as there is poor correlation with long-term outcome. Subsequent neurorehabilitation should always be considered because survival, return to independence and full employment are very likely.