A narrative review published in Experimental Neurology examined the neurological consequences of methamphetamine use. According to this review, methamphetamine use in early adulthood is associated with an increased risk of early-onset stroke, Parkinson’s disease (PD), and parkinsonism.
The aim of this review was to elucidate the neurological damage caused by methamphetamine, which is well documented but poorly understood. Clinical evidence suggests that methamphetamine exposure damages the structure of dopaminergic neurons, which in turn affects brain function.
The authors synthesized the results of previous studies and data from their own research group at the University of New South Wales in Australia. The epidemiology and clinical features of methamphetamine-associated stroke and PD have been described.
Early onset strokes, described as stroke in adults under 45 years of age, have a prevalence of 7 to 15 events per 100,000 person-years in the general population. However, the risk is significantly increased in patients taking methamphetamine.
In a case series from 2009 to 2015, 38 stroke deaths out of 1,649 methamphetamine-related deaths were observed. Two thirds of these deaths occurred in patients under 45 years of age. All but one of these strokes were hemorrhagic and intravenous methamphetamine was the most common route of administration before a stroke.
The clinical picture of a methamphetamine-related stroke is similar to that of a non-traumatic stroke from any cause. The most common distinguishing feature of the patient is age; Methamphetamine-related strokes occur in much younger people who tend to have fewer clinical risk factors for stroke.
The mechanisms involved in stroke include methamphetamine-induced hypertension, tachycardia, thromboembolism, cerebral vasculitis, and vasospasm. Chronic methamphetamine use also damages the walls of blood vessels, which in turn increases their risk of rupture.
Overall, the death rate from methamphetamine-induced strokes appears to be much higher than from other strokes from any cause. Methamphetamine users may also be at a higher risk of permanent disability after a stroke, with an estimated only 25% of people making a full recovery. Methamphetamine is therefore a major cause of neurological deaths and disabilities, especially among younger people.
The evidence linking methamphetamine to early-onset Parkinson’s disease or parkinsonism is less complete. The prevalence of Parkinson’s disease in the general population is estimated to be 2 to 3% in people aged 65 and over; Development before the age of 50 is rare.
In population-based studies, the median age of Parkinson’s disease in methamphetamine users appears to be several years earlier than in the general population. In a 2015 study, the median age of onset of Parkinson’s disease in a cohort of patients with previous or current methamphetamine use was estimated to be 45 years. Two studies conducted in the US found an increased risk of Parkinson’s or Parkinson’s in the years after hospitalization associated with methamphetamine.
The association between methamphetamine use and PD risk is believed to be due to methamphetamine-induced structural damage to dopaminergic neurons. While few neurological imaging studies have been performed in methamphetamine users, preliminary studies have found reduced dopamine levels and the availability of dopamine transporters in the brain after chronic methamphetamine use.
Few studies have evaluated the effectiveness of pharmacological and non-pharmacological treatments for Parkinson’s disease in patients with chronic methamphetamine use. Although methamphetamine abstinence has been shown to somewhat improve the availability of dopamine in the brain, it is not known whether sobriety reverses the risk of Parkinson’s disease.
More research is needed to better understand the neurological damage associated with chronic methamphetamine use, particularly the risk of Parkinson’s and Parkinson’s.
“Evidence from a variety of sources supports an association between methamphetamine use and an increased risk of earlier development of Parkinson’s and Parkinson’s, at least in a subset of people,” the study authors wrote.
Lappin JM, Darke S. Methamphetamine and increased risk of early-onset stroke and Parkinson’s disease: an overview. Exp Neurol. Published online June 21, 2021. doi: 10.1016 / j.expneurol.2021.113793
This article originally appeared on Psychiatry Advisor