OD was relatively common in this paediatric TBI cohort and the hypothesized relationship with severity of injury was supported. It is recommended that information about OD after TBI be routinely provided to children and families. Further research is needed in larger cohorts to support the implementation of routine clinical assessment, understand the relationship between OD and other injury characteristics, determine the functional implications of OD and document recovery trajectories.

The neuropsychological outcomes of pediatric traumatic brain injury (TBI) have received increasing study over the past 20 years and are currently well delineated in the research literature. One outcome that has received little attention is that of olfactory dysfunction after pediatric TBI. This is despite literature indicating that anosmia and olfactory dysfunction are common after adult TBI and are likely to be linked to severity of injury, neuropathology, and executive dysfunction. At a clinical level, anosmia is known to be reported after pediatric TBI. Despite this, little is known about its prevalence and recovery. A systematic review was undertaken to provide objective information about olfactory dysfunction post-TBI in children. Despite broad inclusion criteria, only four published studies were identified. The studies found were limited by methodological weaknesses, variability in measures, small sample size, and difficulty of comparison across cohorts studied. Despite this, they reported consistent findings of anosmia and olfactory dysfunction in their TBI cohorts and identified a dose-response relationship between severity of injury and olfactory dysfunction. The results of the studies are discussed in terms of relevant findings, limitations, and areas requiring further exploration.

Overall our findings provide little support for a significant relationship between EF and OD in pTBI. In particular, there was no strong evidence that acute olfactory function is an accurate predictor of later EF in pTBI. Given the dearth of pediatric research, the limitations of our study and the potential significance of acute olfactory performance as an early marker of later EF deficits in children, further investigation is warranted.