Abstract Parkinson disease is a multi-factorial neurological disorder instigated by a collapse in the dopaminergic pathways due to an inhibition in the normal flow of dopamine in the brain neurons. The prevalence of this disease is notable among people who are over 60 years and above. The ineffectiveness of most drugs currently in use with no definite treatment regimes is hinged on the lack of understanding of the cellular and molecular processes that transcends in the manifestation of its pathogenesis. Understanding the biochemical processes of the dopaminergic pathways is essential for specificities in drug design and discovery as drugs must be designed to target the missing functionalities thus avoiding drug failure. In this review, series of causative agents classified under genetic and environmental factors were discussed alongside their underlining cellular and molecular pathways that reveals failure of biochemical systems and release of harmful enzymatic activities.
Keywords Parkinson, disease, neurological, dopaminergic, pathways, pathogenesis, drugs, cellular, molecular, disorder.