Use of methamphetamine is associated with an increased risk of major damage to arteries in the neck and stroke, according to two case reports published in the December 26th edition of Neurology. The cases involved young women who experienced speech difficulties and weakness following use of methamphetamine. The study’s lead author, Wengui Yu commented, "it appears methamphetamine use is toxic to large blood vessels".
Methamphetamine use is an major health and social concern. Studies have suggested that use of methamphetamine can worsen damage to the brain caused by HIV and increase HIV’s ability to replicate in the brain. There is also conflicting evidence regarding methamphetamine’s association with risky sexual behaviour.
The case reports involved two HIV-negative women, aged 36 and 29. Following use of methamphetamine they developed sudden onset speech problems and weakness. Brain scans indicated that both women had experienced severe strokes and that there had been tears to the carotid arteries - the main arteries in the neck leading to the brain. According to a scale used to assess stroke severity, the National Institutes of Health Stroke Scale, the 36-year-old woman received a score of 21. She required treatment with a clot-busting drug known as a tissue plasminogen activator. The 29-year-old woman, required a stent (a tube inserted into the artery) to treat the blockage and received a score of 17. Stroke Scale scores over 16 predict a high probability of death or severe disability.
"This is the first time there's been a possible link between methamphetamine use and carotid artery dissection, a tear in the neck artery," comment the investigators".
Other than methamphetamine use, neither of the women had any other significant risk factors for stroke. Both women recovered with mild to moderate disabilities after they received acute stroke therapy.
Anti-HIV therapy can cause metabolic changes than can increase the long term risk of stroke. Some studies have found higher levels of methamphetamine use amongst HIV-positive individuals than their HIV-negative peers. These case studies will therefore be an issue of concern for HIV-positive users of the drug. It is also worth noting that fatal interaction between methamphetamine and the protease inhibitor, ritonavir, has been observed.
Mc Intosh A et al. Carotid artery dissection and middle cerebral artery stroke following methamphetamine use Neurology 67: 2259-2260, 2006.