Neurodegenerative Diseases: Mechanism, Limitations, and Emerging Treatments

Neurodegenerative diseases, including Alzheimers disease (AD), Parkinsons disease (PD), Huntingtons disease (HD), and amyotropic lateral sclerosis (ALS), are characterized by gradual neural damage, leading to cognitive and behavioral impairments. Their prevalence increased along the aging population, bringing significant medical, social, and economic problems worldwide. Thorough and abundant research on these diseases have been conducted since their discovery, including aspects such as their characteristics, mechanisms, causes, and stages of development. However, despite this extensive research, effective therapies still remain undiscovered, largely due to complicatedness and multifactoriality of their pathogenesis. In recent years, advances in molecular biology, technologies, and models are starting to provide possible approaches such as targeted protein clearance, anti-inflammatory strategies, gene therapy, and metabolic modulation to address these gaps. This review summarizes shared and distinct features across major neurodegenerative diseases, the core pathogenic mechanisms, progress in disease modeling and biomarker development, and emerging therapeutic strategies. By integrating current mechanistic insights with innovative research tools, this work presents the importance of early diagnosis and precision medicine interventions, aiming to inform future research directions and improve patient outcomes.