Olfactory function in acute traumatic brain injury.

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Olfactory and executive dysfunctions following orbito-basal lesions in traumatic brain injury.

OBJECTIVE: To study the acute relationship between olfactory function and traumatic brain injury (TBI), cognitive functions and outcome. METHODS: Sixty-two patients with TBI were evaluated within the first 2 weeks following TBI. The Sniffin'Sticks identification test was used to assess olfaction. A neuropsychological evaluation was carried out to assess attention, verbal fluency, naming, memory, problem-solving and mental flexibility. The extended Glasgow Outcome Scale (GOSE) and the Disability Rating Scale (DRS) were rated at discharge from acute care. RESULTS: Traumatic lesions located in the basal frontal area resulted in odour identification scores that were significantly lower than when lesions were elsewhere (p < 0.001). A significant positive correlation was shown between odour identification scores and mental flexibility scores (p = 0.004) and patients with hyposmia had worse performances on executive tests measuring problem-solving, verbal fluency and mental flexibility (p < 0.01). Moreover, the odour identification score and the DRS total score were related (p = 0.019). CONCLUSIONS: These findings add information regarding acute olfactory status following TBI and provide evidence on the importance of assessing olfaction very early post-TBI in order to plan intervention and determine what accident prevention advice will be required for home or work re-integration.