Background and Aims:

In pure-motor ALS patients, we recently observed that smaller volume of the left pallidum was related with impaired recognition of disgust. In the present study, we investigated the resting-state functional connectivity (RS-FC) of the pallidum in ALS, and the relationship between RS-FC changes and disgust recognition.

Methods:

19 pure-motor ALS patients and 52 matched healthy controls underwent RS functional MRI and a neuropsychological assessment including the Comprehensive Affect Testing System (CATS), investigating emotion recognition. A seed-based RS-FC analysis was run between the left and right pallidum and the rest of the brain, and compared between groups. Correlation analyses were run between the RS-FC significant changes and patients’ performance in recognizing disgust.

Results:

Compared to controls, ALS presented reduced RS-FC between bilateral pallidum and right superior and middle frontal gyri, and increased RS-FC between bilateral pallidum and left superior temporal and postcentral gyri, and left Rolandic operculum. Increased RS-FC was observed between left pallidum and left supramarginal gyrus and between right pallidum and contralateral insula and thalamus. In patients, lower performance in recognizing disgust was related with reduced RS-FC between bilateral pallidum and right middle and superior frontal gyri, and with increased RS-FC between bilateral pallidum and left postcentral gyrus and Rolandic operculum.

Conclusions:

In a cognitively unimpaired ALS patients, reduced pallidum-frontal RS-FC and increased pallidum-insular-thalamic RS-FC may suggest a fronto-striatal functional disconnection, which could have a role in the lower ability of patients in recognizing disgust.

Funding: Italian Ministry of Health (GR-2013-02357415); European Research Council (StG-2016_714388_NeuroTRACK).