Itching Frequency and Neuroanatomic Correlates in Frontotemporal Lobar Degeneration

Area of Science:

• Neuroscience
• Geriatrics
• Dermatology

Background:

• Itching is a common symptom in older adults, often linked to skin or systemic issues.
• Itching involves brain regions also implicated in frontotemporal lobar degeneration spectrum disorders (FTLD-SD), suggesting a potential neurodegenerative link.
• Itching of undetermined origin (IUO) may signal an underlying neurodegenerative process.

Purpose of the Study:

• To compare the prevalence of itching in FTLD-SD versus Alzheimer disease (AD).
• To identify the neuroanatomical correlates of IUO.

Main Methods:

• A case-control study analyzed data and brain MRIs from patients with FTLD-SD or AD.
• Participant data were reviewed to identify cases of IUO.
• Structural brain MRI was performed within six months of diagnosis.

Main Results:

• Itching was significantly more frequent in FTLD-SD (38%) compared to AD (18%).
• Patients with FTLD-SD had 2.4 times higher odds of experiencing itching than other dementia cases.
• IUO was associated with gray matter atrophy in the amygdala, insula, precentral gyrus, cingulum, and thalamus, particularly in FTLD-SD.

Conclusions:

• FTLD-SD is disproportionately represented among individuals with IUO compared to AD.
• Dysfunction in the right anterior insula and connected regions contributes to itching in FTLD-SD.
• Physician awareness of the neurodegeneration-itching link may aid in managing itch in the elderly; further research on treatments is warranted.