Parkinsonism has been reported to occur due to a number of toxins including metals (iron, copper, and manganese), the by-product 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), and certain pesticides, such as paraquat, organochlorine, and carbamate. The specific mechanisms by which these neurotoxins damage nigral dopaminergic neurons are unknown. An important mechanism by which neurotoxins could selectively target dopaminergic cells may be via uptake through the presynaptic dopamine transporter. Because of the potential role of pesticides as an environmental risk factor for Parkinson’s disease (PD), several paradigms have been developed to create animal models of PD including MPTP, 6-hydroxydopamine, and rotenone. Despite clinical similarities, the principal differences between PD and these animal models are the lack of progressive neurodegeneration and the absence of typical neuronal Lewy bodies in the animal models.
KeywordsIntensive Care Unit Botulinum Toxin Specific Mechanism Environmental Risk Factor Facial Masking
21 Toxin-induced parkinsonism.mp4 (MP4 21,336KB)
The patient exhibits signs of akinetic-rigid parkinsonism with severe facial masking and increased blink frequency. He displays bilateral hand dystonia and marked left-sided hypokinesia. His gait is associated with absent left arm swing.