Olfactory bulb volume in patients with temporal lobe epilepsy

Area of Science:

• Neuroscience
• Neurology
• Olfactory System Research

Background:

• Temporal lobe epilepsy (TLE) is frequently associated with olfactory deficits.
• The precise mechanisms linking TLE to olfactory dysfunction, particularly its impact on the olfactory bulb (OB), require further investigation.

Purpose of the Study:

• To investigate olfactory bulb (OB) volume in patients diagnosed with temporal lobe epilepsy (TLE).
• To determine if the olfactory deficit observed in TLE patients influences the OB through a top-down effect from the cerebral cortex.

Main Methods:

• Olfactory testing using the Sniffin' Sticks device to assess odor threshold and identification in 20 TLE patients and 20 controls.
• Magnetic Resonance (MR) imaging with T2-weighted fast spin-echo sequences to measure OB volumes.

Main Results:

• TLE patients exhibited significantly impaired olfactory function compared to healthy controls (p < 0.001).
• A significant reduction in olfactory bulb (OB) volumes was observed in TLE patients (p = 0.013).
• The observed OB volume deficit did not correlate with the laterality of the epileptic focus.

Conclusions:

• The findings indicate that olfactory bulb (OB) volume is reduced in TLE patients, correlating with their olfactory dysfunction.
• This suggests that cortical epileptic activity in TLE can lead to structural changes in the olfactory bulb (OB), demonstrating a top-down influence.