Physiological, behavioral and subjective sadness reactivity in frontotemporal dementia subtypes

Area of Science:

• Neuroscience
• Clinical Neurology
• Psychology

Background:

• Frontotemporal dementia (FTD) is a neurodegenerative disorder marked by socioemotional deficits.
• FTD comprises three subtypes: behavioral variant FTD (bvFTD), semantic variant primary progressive aphasia (svPPA), and non-fluent variant primary progressive aphasia (nfvPPA).
• Emotional reactivity is impaired in bvFTD and svPPA, but less studied in nfvPPA.

Purpose of the Study:

• To investigate emotional reactivity to sadness across physiological, facial, and subjective measures in FTD subtypes.
• To explore the neural correlates of diminished sadness reactivity using voxel-based morphometry.
• To characterize emotional deficits and associated neurodegeneration in FTD.

Main Methods:

• Examined emotional reactivity (physiology, facial behavior, subjective experience) in 105 FTD patients (bvFTD, svPPA, nfvPPA) and 27 controls using a sad film stimulus.
• Utilized voxel-based morphometry to assess neural correlates of reactivity in a subset of participants.
• Compared physiological responses (respiration rate, blood pressure), facial expressions, and self-reported emotions.

Main Results:

• All FTD subtypes exhibited reduced physiological responding (respiration rate, diastolic blood pressure).
• bvFTD and svPPA patients reported diminished subjective emotional experience.
• No FTD subtype showed impaired facial emotional behavior; brain region volumes correlated with sadness reactivity deficits.

Conclusions:

• Emotional impairments in FTD extend to sadness reactivity across multiple domains.
• Sadness reactivity deficits vary among FTD subtypes, highlighting distinct neurodegenerative patterns.
• Comprehensive assessment of emotional reactivity is crucial for understanding FTD and its neurobiological underpinnings.