Individual differences in interoceptive accuracy and prediction error in motor functional neurological disorders: A...

Area of Science:

• Neuroscience
• Neurology
• Psychiatry

Background:

• Motor functional neurological disorders (mFND) lack investigation into interoception and neuroanatomy links.
• Interoception is theoretically relevant to mFND pathophysiology.
• Understanding these relationships is crucial for advancing mFND research.

Purpose of the Study:

• To investigate white matter integrity in mFND patients compared to healthy controls.
• To explore associations between fiber bundle integrity and cardiac interoception in mFND.
• To identify neuroanatomical underpinnings of interoceptive processing in mFND.

Main Methods:

• Voxel-based analysis and tractography were used to quantify fractional anisotropy (FA).
• 38 mFND patients and 38 healthy controls (HCs) were compared.
• Secondary analyses included subgroups: functional seizures (FND-seiz) and functional movement disorders, with within-group analyses for mFND patients.

Main Results:

• No significant between-group differences in interoceptive accuracy or FA were found between mFND patients and HCs.
• The FND-seiz subgroup exhibited reduced integrity in right-lateralized tracts, including the extreme capsule/inferior fronto-occipital fasciculus and arcuate fasciculus.
• Individual differences in interoceptive accuracy and prediction error in mFND correlated with fiber bundle integrity from regions like the insula and temporoparietal junction.

Conclusions:

• This is the first study to link brain-interoception relationships in mFND.
• Individual interoceptive differences in mFND map onto multimodal integration-related fiber bundles.
• Right-lateralized limbic and associative tract disruptions characterize FND-seiz patients.