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Olfactory Memory Dysfunction in Patients with Traumatic Brain Injury
Medrxiv : the Preprint Server for Health Sciences
|July 30, 2026
Summary
Traumatic brain injury (TBI) affects long-term olfactory function, impacting odor identification, discrimination, and memory. Loss of consciousness duration is particularly linked to impaired odor memory, suggesting it captures injury beyond TBI severity alone.
Area of Science:
- Neuroscience
- Neurology
- Sensory Science
Background:
- Clinical indices for traumatic brain injury (TBI) severity may lack prognostic precision.
- Olfactory function, reliant on sensory, limbic, and memory networks, offers a potential objective marker for neural dysfunction post-TBI.
Purpose of the Study:
- To investigate the association between TBI severity and long-term olfactory function.
- To determine if loss of consciousness (LOC) characteristics correlate with specific olfactory deficits.
Main Methods:
- Seventy-nine TBI patients (48 mild, 31 moderate-to-severe) and 59 controls underwent olfactory testing (odor identification, discrimination, memory) years post-injury.
- General linear models analyzed olfactory outcomes against TBI severity and LOC, adjusting for demographic factors.
Main Results:
- TBI severity correlated significantly with all olfactory measures (odor identification, discrimination, memory).
- Moderate-to-severe TBI patients showed deficits across all olfactory tests compared to controls.
- Mild TBI patients exhibited impairments in odor discrimination and memory.
- Prolonged or unknown LOC duration was specifically linked to poorer odor memory performance.
Conclusions:
- Long-term olfactory function, including identification, discrimination, and memory, is demonstrably impaired by TBI severity.
- Olfactory memory appears particularly sensitive to LOC duration, potentially reflecting injury aspects not captured by standard TBI severity classifications.
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