Clinicoradiological features in amyotrophic lateral sclerosis patients with olfactory dysfunction

Area of Science:

• Neuroscience
• Neurology

Background:

• Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease affecting motor neurons.
• Olfactory dysfunction is observed in ALS, but its clinical and radiological correlates are not well understood.

Purpose of the Study:

• To investigate the association between olfactory dysfunction and clinicoradiological features in ALS patients.
• To explore brain structural changes related to olfactory dysfunction in ALS using MRI.

Main Methods:

• 30 ALS patients and 53 healthy controls (HCs) underwent the Odor Stick Identification Test for Japanese (OSIT-J).
• Clinical data (disease duration, ALSFRS-R, cognitive function) and MRI scans were collected.
• Voxel-based morphometry (VBM) analyzed MRI for atrophic changes correlated with OSIT-J scores.

Main Results:

• ALS patients showed significantly lower OSIT-J scores compared to HCs (p < 0.001).
• OSIT-J scores correlated with age, executive function (Frontal Assessment Battery, word fluencies), and memory recognition (ADAS-Jcog).
• VBM revealed correlations between OSIT-J scores and atrophy in the left orbital cortex and right hippocampus.

Conclusions:

• ALS patients frequently experience olfactory dysfunction.
• Olfactory dysfunction is associated with structural changes in the orbital cortex and hippocampus.
• Olfactory testing may serve as a valuable screening tool for frontotemporal alterations in ALS.