Locus Coeruleus Degeneration Differs Between Frontotemporal Lobar Degeneration Subtypes

Area of Science:

• Neuroscience
• Neuropathology
• Neurodegenerative Diseases

Background:

• Locus coeruleus (LC) degeneration is understudied in frontotemporal lobar degeneration (FTLD).
• Differences in LC pathology may vary based on FTLD proteinopathy (tau, TDP, FUS).

Purpose of the Study:

• To investigate locus coeruleus (LC) degeneration across different FTLD subtypes.
• To compare LC pathology in FTLD with tau, TDP, and FUS proteinopathies.
• To assess LC degeneration in FTLD against control groups (healthy and vascular cognitive impairment).

Main Methods:

• Examined neuropathological cases of FTLD (tau, TDP, FUS), vascular cognitive impairment (VCI), and healthy controls.
• Assessed micro- and macroscopical LC degeneration, including neuronal count and depigmentation.
• Compared degeneration severity across FTLD subgroups and control groups.

Main Results:

• All FTLD groups exhibited significantly higher microscopical LC degeneration than controls.
• FTLD-tau cases showed more severe micro- and macroscopical LC degeneration than FTLD-TDP cases.
• Age positively correlated with LC degeneration in FTLD-tau, but not FTLD-TDP.

Conclusions:

• Microscopic LC degeneration is prevalent in all FTLD cases compared to controls.
• Macroscopic LC degeneration is more pronounced in FTLD-tau than FTLD-TDP.
• Differential LC degeneration patterns in FTLD subgroups may support diagnostic imaging.