¹Dr Ibrahim Khan, ²Ansa Batool, ³Dr Abdul Jabbar, ⁴Dr Jahangir Liaquat, ⁵Dr.Darya
khan laghari, ⁶Dr Allah Rakha

Biomarkers in Neurodegenerative Diseases:
Early Detection of Alzheimer’s and Parkinson’s
Disease

Abstract:

Neurodegenerative diseases are progressive disorders characterized by the accumulation of pathological proteins, neuronal dysfunction, synaptic loss, and progressive neuronal degeneration. Alzheimer’s disease (AD) and Parkinson’s disease (PD) are among the most common neurodegenerative disorders and are associated with substantial cognitive, motor, functional, and socioeconomic consequences. Biomarkers have increasingly become important for detecting pathological changes before advanced clinical manifestations develop.The study was designed to evaluate the role of established and emerging biomarkers in the early detection of Alzheimer’s and Parkinson’s disease, with emphasis on blood, cerebrospinal fluid, imaging, and molecular biomarkers.A comparative clinical and biomarker-focused framework was used to assess biomarkers associated with AD and PD. Biomarkers were evaluated according to their biological targets, specimen requirements, diagnostic applications, relationship with disease pathology, and potential usefulness during early disease stages. Established and emerging
evidence regarding amyloid, tau, neurofilament, and α-synuclein biomarkers was considered.Alzheimer’s disease biomarkers demonstrated strong potential for detecting amyloid and tau pathology, particularly phosphorylated tau species and amyloid-β-based measures. Plasma p-tau217 and related blood-based biomarkers provided promising approaches for less￾invasive detection of AD pathology. In Parkinson’s disease, α-synuclein seed amplification assays demonstrated strong potential for detecting pathological α-synuclein, while neurofilament light chain showed usefulness for identifying neuronal injury and distinguishing PD from some atypical parkinsonian disorders.Biomarkers provided an increasingly important foundation for biological diagnosis and early detection of neurodegenerative diseases. Blood-based biomarkers offered practical advantages for AD, whereas α-synuclein-based molecular assays represented an important advance for PD. Integration of biomarkers with clinical assessment and imaging was expected to improve diagnostic accuracy and facilitate earlier disease-specific intervention.

Key words
Neurodegenerative diseases; Alzheimer’s disease; Parkinson’s disease; biomarkers;
phosphorylated tau; amyloid-β; α-synuclein; neurofilament light chain;

GlobalHealth & Medicine. 2026; 8(3):291-305. Original Article
DOI:10.35772/ghm.2026.01069

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