Methamphetamine Use and Brain Aneurysm
A brain aneurysm is a weakening in the wall of a brain artery that causes that wall to balloon or bulge abnormally. If an artery weakened in this manner bursts open inside the brain, it will trigger a life-threatening form of bleeding called an intracranial hemorrhage. A number of different types of aneurysms can appear at different locations inside the skull. Use of the illegal drug methamphetamine can potentially lead to the development of a form of brain aneurysm known as a berry aneurysm.
Blood reaches the brain through two paired sets of arteries, called the right and left vertebral arteries and the right and left internal carotid arteries. Generally speaking, the vertebral arteries supply blood to rear areas of the brain, while the internal carotid arteries supply blood to the front areas of the brain. At the bottom of the brain, the vertebral and carotid arteries also form the basis for an interconnecting ring of arteries commonly known as the Circle of Willis. Arteries stemming from this ring supply blood to various regions of tissue throughout the brain.
Brain Aneurysm Basics
As a rule, aneurysms develop in arteries, not veins; this is true because arteries bear the brunt of the force required to pump blood from the heart to the rest of the body. Roughly 5 percent of all Americans have an aneurysm in one of the arteries inside their brains, the US National Library of Medicine reports. However, the vast majority of these aneurysms never rupture and cause no symptoms or real-world problems. When a rupture does occur inside the brain (or outside the brain within the skull cavity), it sometimes starts as a slow form of bleeding that grows worse over time. In other cases, a larger rupture occurs and produces immediate, extensive bleeding. Problems can also occur if an intact aneurysm grows large enough to push against nearby brain tissues.
The specific symptoms of a brain aneurysm depend upon a number of factors, including the location of weakened artery, whether the artery ruptures or remains intact, and whether a ruptured artery leaks blood slowly or releases blood rapidly into the surrounding tissues. Generally speaking, common symptoms of a damaging brain aneurysm include a severe headache that appears without warning, pain that appears in the eyes or neck, neck stiffness, the onset of double vision, and partial or total vision loss.
Symptoms specifically associated with a ruptured brain aneurysm include drooping eyelids, headaches, nausea, vomiting, unusual sleepiness or sluggishness, impaired speech, mental confusion, the sorts of vision changes mentioned in the previous paragraph, seizures, unexplained movement problems or muscle weakness, and numbness or other unexplained losses of normal nervous system function. Some people also lose consciousness or enter the nonresponsive state called a coma. People with ruptured brain aneurysms frequently die, even when they receive appropriate emergency medical treatment.
The Effects of Methamphetamine Use
When methamphetamine enters the body, it produces significant increases in the levels of a neurotransmitting chemical in the central nervous system (brain and spinal cord) called norepinephrine or noradrenaline. Among its many functions, this chemical helps control normal function in the body’s arteries and veins, and when its levels rise, it produces a narrowing of these blood vessels that doctors commonly refer to as vasoconstriction. In turn, the presence of vasoconstriction increases the amount of pressure exerted on the walls of arteries located throughout the body, including the arteries found in and around the brain. The presence of methamphetamine in the bloodstream can also trigger a condition called vasculitis, which occurs when the immune system produces levels of inflammation that damage the integrity of these vessels. One of the potential consequences of vasculitis is a dangerous weakening of the artery walls.
Methamphetamine’s influence on artery health can lead to the formation of a common type of brain aneurysm called a berry aneurysm, according to a 2008 report by the University of Maryland School of Medicine. In addition, methamphetamine’s influence can cause a berry aneurysm to burst open and produce slow or rapid bleeding inside or outside the brain. Berry aneurysms get their name because they have a berry-like shape. Typically, they range in diameter from several millimeters to a centimeter or more; however, in some cases, unusually large berry aneurysms grow larger than two full centimeters in diameter. Depending on individual circumstances, an aneurysm in a methamphetamine user can burst open without warning, or rupture during the course of a toxic reaction to the drug commonly known as a methamphetamine overdose.