Daniel Fu-Chang Tsai, Yu-Chen Chou
Neurodegenerative diseases cause not only progressive cognitive and physical decline, but also profound disruption to the continuity and integrity of personhood. Traditional approaches often treat memory or decisional autonomy as the core of personhood; yet such a lens risks overlooking how these illnesses concretely reshape relationships, lived dignity, and the moral texture of care. This paper first outlines major categories of neurodegenerative diseases, then examines stage-specific clinical impacts and corresponding ethical challenges. It further addresses the technological and ethical issues raised by AI-assisted early diagnosis, the effects of patients' neuropsychiatric and behavioral symptoms on caregivers, and-centrally-the philosophical question of how personhood and dignity should be understood when cognition deteriorates. By tracing the ethical focus as it shifts from protecting autonomy, to balancing safety and freedom, and finally to prioritizing comfort and dignity near the end of life, this analysis argues for a care ethics approach that integrates respect for agency with relational responsibilities and the preservation of dignity across disease trajectories.