Dementia Care Research and Psychosocial Factors

Area of Science:

• Neuroscience
• Neurology
• Cognitive Science

Background:

• Primary progressive aphasia (PPA) is a neurodegenerative syndrome characterized by progressive language impairment.
• Current treatments for PPA are limited, with no established pharmacological or neuromodulation strategies offering significant symptom improvement.
• Neuroimaging reveals selective involvement of the language network in PPA, suggesting targeted interventions may be beneficial.

Purpose of the Study:

• To investigate the efficacy of repetitive transcranial magnetic stimulation (rTMS) in modulating functional connectivity within the language network in patients with PPA.
• To assess the impact of rTMS on language function and communication abilities across different subtypes of PPA.

Main Methods:

• A double-blinded, sham-controlled, cross-over study involving 10 PPA patients (4 lvPPA, 2 nfvPPA, 1 svPPA, 3 PPAOS).
• Intermittent theta burst stimulation (iTBS) was administered over 10 days, targeting the left caudal middle frontal gyrus individualized to each patient's language network.
• Language assessments and resting-state fMRI were conducted at baseline, post-active iTBS, and post-sham iTBS to evaluate changes in language performance and functional connectivity.

Main Results:

• Active iTBS led to significant improvements in language function and functional communication across all PPA subtypes and PPAOS.
• These language enhancements were observed in both standardized assessments and functional communication evaluations.
• Active iTBS also resulted in increased functional connectivity within the language network and other cognitive networks.

Conclusions:

• Personalized, functional-network guided iTBS shows preliminary promise for improving language impairments in a diverse group of PPA and PPAOS patients.
• The observed improvements in language tests correlate with increased functional network connectivity, suggesting a neural mechanism for TMS-induced benefits.
• This study provides evidence for iTBS as a potential therapeutic strategy for PPA and PPAOS.