Olfactory function in acute traumatic brain injury

Traumatic brain injury (TBI) represents a significant public health problem and is associated with a high rate of mortality and morbidity. Although TBI is amongst the most common causes of olfactory dysfunction the relationship between injury severity and olfactory problems has not yet been investigated with validated and standardized methods in the first days following the TBI.

We measured olfactory function in 63 patients admitted with TBI within the first 12 days following the trauma by means of the Sniffin' Sticks identification test (quantitative assessment) and a parosmia questionnaire (qualitative assessment). TBI severity was determined by means of the Glasgow Coma Scale (GCS) and by duration of post-traumatic amnesia (PTA) as measured by the Galveston Orientation and Amnesia Test.

Poor olfactory scores correlated with a longer amnesia period, but not with GCS scores. Further, we observed higher parosmia scores in assault victims than in victims of falls or motor vehicle collisions.

We show that PTA is intimately related to olfactory problems following a TBI. Thus, a thorough evaluation of olfaction is essential in order to detect posttraumatic olfactory dysfunction and to take appropriate actions early on to help the individual deal with this impairment.