A stroke, previously known medically as a cerebrovascular accident (CVA), is the rapid loss of brain function(s) due to disturbance in the blood supply to the brain. This can be due to ischemia (lack of blood flow) caused by blockage (thrombosis, arterial embolism), or a hemorrhage (leakage of blood). As a result, the affected area of the brain cannot function, which might result in an inability to move one or more limbs on one side of the body, inability to understand or formulate speech, or an inability to see one side of the visual field.
A stroke is a medical emergency and can cause permanent neurological damage, complications, and death. It is the leading cause of adult disability in the United States and Europe and the second leading cause of death worldwide. Risk factors for stroke include old age, hypertension (high blood pressure), previous stroke or transient ischemic attack (TIA), diabetes, high cholesterol, cigarette smoking and atrial fibrillation. High blood pressure is the most important modifiable risk factor of stroke.
In an ischemic stroke, blood supply to part of the brain is decreased, leading to dysfunction of the brain tissue in that area. There are four reasons why this might happen:
Thrombosis (obstruction of a blood vessel by a blood clot forming locally)
Embolism (obstruction due to an embolus from elsewhere in the body, see below),
Systemic hypoperfusion (general decrease in blood supply, e.g., in shock)
Venous thrombosis.
People missing some or all of their teeth or who have significant loss of bone and tissue surrounding their teeth may be at an increased risk for having a stroke, according to a new study that appeared in the October issue of the Journal of Periodontology (JOP).
Researchers from Boston University investigated the relationship between periodontal disease and history of stroke in patients 60 years of age and older by examining the data of the Third National Health and Nutrition Examination Survey (NHANES III).
"We found that patients 60 years and older who were edentulous, partially edentulous and/or had significant clinical attachment loss were more likely to have a history of stroke compared to dentate adults without significant clinical attachment loss," said Dr. Martha E. Nunn, Goldman School of Dental Medicine, Boston University. "However, based on the results of this study, it is unclear whether periodontal disease is an independent risk factor for stroke or simply a risk marker that reflects negative effects of risk factors common to both periodontal disease and stroke."
Age, tobacco use, hypertension, diabetes, serum glucose, C-Reactive protein (CRP) and alcohol intake were also included as additional risk factors in this study. These confounders are independent risk factors for cardiovascular disease and if left untreated, periodontitis has been shown to have harmful effects on the control of diabetes, serum glucose levels and increases CRP levels.
