%0 Journal Article
%T Methamphetamine and Parkinson's Disease
%A Noelia Granado
%A Sara Ares-Santos
%A Rosario Moratalla
%J Parkinson's Disease
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/308052
%X Parkinson's disease (PD) is a neurodegenerative disorder predominantly affecting the elderly. The aetiology of the disease is not known, but age and environmental factors play an important role. Although more than a dozen gene mutations associated with familial forms of Parkinson's disease have been described, fewer than 10% of all cases can be explained by genetic abnormalities. The molecular basis of Parkinson's disease is the loss of dopamine in the basal ganglia (caudate/putamen) due to the degeneration of dopaminergic neurons in the substantia nigra, which leads to the motor impairment characteristic of the disease. Methamphetamine is the second most widely used illicit drug in the world. In rodents, methamphetamine exposure damages dopaminergic neurons in the substantia nigra, resulting in a significant loss of dopamine in the striatum. Biochemical and neuroimaging studies in human methamphetamine users have shown decreased levels of dopamine and dopamine transporter as well as prominent microglial activation in the striatum and other areas of the brain, changes similar to those observed in PD patients. Consistent with these similarities, recent epidemiological studies have shown that methamphetamine users are almost twice as likely as non-users to develop PD, despite the fact that methamphetamine abuse and PD have distinct symptomatic profiles. 1. Parkinson¡¯s Disease Parkinson¡¯s disease (PD) is the second most common neurodegenerative disorder after Alzheimer¡¯s disease, affecting an estimated 7 to 10 million people worldwide. Incidence of the disease increases with age. PD usually affects people over the age of 50, but an estimated 4% of PD cases is diagnosed before the age of 50. Early in the course of the disease, the most obvious symptoms are movement-related. These include shaking, rigidity, slowness of movement, and difficulty with walking and gait. Later, cognitive and behavioral problems may arise, with dementia commonly occurring in the advanced stages of the disease. Other symptoms include sensory, sleep, and emotional problems. PD is caused by degeneration of midbrain dopaminergic neurons that project to the striatum. The loss of striatal dopamine is responsible for the major symptoms of the disease. Although a small proportion of cases can be attributed to known genetic factors, most cases of PD are idiopathic. While the aetiology of dopaminergic neuronal demise is elusive, a combination of genetic susceptibilities, age, and environmental factors seems to play a critical role [1]. Dopamine degeneration process in PD involves abnormal
%U http://www.hindawi.com/journals/pd/2013/308052/