Neurodegenerative

Neurodegeneration refers to the progressive loss of structure or function of neurons, leading to neuronal death. It encompasses a broad range of disorders known as neurodegenerative diseases, which typically affect aging populations and can involve disturbances in cognition, movement, behavior, and autonomic function. Common examples include Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, frontotemporal dementia, and spinocerebellar ataxias, as well as prion diseases. These conditions are often marked by selective vulnerability of specific neuronal populations and, in many cases, by intracellular protein aggregates such as amyloid beta and tau in Alzheimer's, alpha-synuclein in Parkinson's, or huntingtin in Huntington's disease.

Etiology is usually multifactorial, involving genetic predispositions, environmental factors, and the aging process. Pathophysiology commonly features impaired proteostasis, mitochondrial dysfunction, oxidative stress, neuroinflammation, excitotoxicity, and synaptic loss, which together contribute to progressive neurological decline.

Clinical presentation varies by disease and brain region affected, but may include memory impairment, motor dysfunction, language and executive deficits, behavioral changes, and autonomic disturbances. Diagnosis relies on clinical assessment supported by neuroimaging, biomarkers in cerebrospinal fluid or blood, and, when appropriate, genetic testing. There is no cure for most neurodegenerative diseases; management emphasizes symptom relief, rehabilitation, and supportive care. Some conditions have disease-modifying therapies aiming to slow progression, while others rely on symptomatic medications and multidisciplinary care. Ongoing research explores gene therapy, antisense approaches, stem cell therapies, and strategies to prevent or reduce protein aggregation and neuroinflammation.