A Role for Oral Health Personnel in Stroke Prevention
Jukka H. Meurman, MD, PhD
Possible links between stroke and periodontal disease are reviewed in this article. Topics covered include the signs and symptoms of stroke, dental and other infections associated with stroke, and the role of oral healthcare personnel in the prevention of stroke and treatment of stroke patients.
Stroke is the second leading cause of death of people 60 years and older in industrialized countries. Annually, about 15 million people worldwide experience a stroke. Stroke can be classified as hemorrhagic or ischemic cerebral infarction; ischemic stroke accounts for 80% of cases. The World Health Organization defines stroke as follows: “A stroke is caused by the interruption of the blood supply to the brain, usually because a blood vessel bursts or is blocked by a clot. This cuts off the supply of oxygen and nutrients, causing damage to the brain tissue.” Symptoms and signs of stroke depend on the location and extent of the tissue injury. Ischemic stroke patients often have preceding transient ischemic attacks (TIA) before the “final” stroke. TIA symptoms are the same as in stroke, but they subside within an hour, and no signs of cerebral infarction can be seen in radiologic examinations.1
Symptoms and Signs of Stroke
Clinical manifestations of stroke are listed in Table 1. Severe stroke causes sudden death. Modern antithrombotic therapy has revolutionized treatment of stroke. However, the therapy must be started as soon as possible after the attack; every minute counts. The rule of thumb is that the patient must be admitted to the hospital within 3 hours; the 3-hour window is often advertised in posters and pamphlets targeting the public. Many countries have special stroke treatment units and stroke centers, and telemedicine today has brought antithrombotic treatment of stroke patients into almost every emergency hospital.1,2
If treatment is successful, the patient may return to having a fairly normal life, depending on the severity of the attack. Rehabilitation of stroke patients needs to be started as soon as the patient’s medical condition allows. In many cases the outcome is quite positive, although problems in dexterity and some degree of paralysis may continue to exist. Manual dexterity is important for daily maintenance of satisfactory oral hygiene. Therefore, from the dental point of view, maintenance may be challenging among stroke patients. Special aids are available, however; for example, electric toothbrushes should be recommended.
Infections in the Etiology of Stroke
Infections are known to pose risk for stroke.1 Table 2 lists the infections most commonly discussed as risk factors for stroke. The highly prevalent upper respiratory tract infections have been known for a long time to increase the risk of stroke. Chronic infections such as bronchitis and chlamydia also need to be considered. More recently, dental infections have been added to the concerns.
The paradigm of the associations between infections and stroke is depicted in Figure 1. Any infection causes upregulation of chemokines, cytokines, and other inflammatory mediators that, in turn, can have detrimental effects at the cellular and tissue level. For example, activation of blood coagulation systems may cause clotting and embolus spread in cerebral arteries. However, inflammatory reactions are highly complex. Many factors, such as genetics, dietary customs leading to obesity and metabolic syndrome, and behavioral factors, such as smoking and alcohol use, modify the systemic reactions. Nevertheless, it is clear that infection-caused inflammation poses a marked risk for stroke.
Oral Infections and Stroke
Data are accumulating that periodontitis, particularly, is statistically associated with stroke. In a recent Medline database search using the keywords shown in Table 3, a trend could be seen that the number of articles on stroke are increasing. Treatment studies are still scarce, however. Table 4 gives examples of studies where the association between periodontal disease and stroke has been investigated.3-8 Some of these studies have shown an association while others have not. Hence, more data are needed. As shown in Table 5, treatment of periodontal disease seems to improve carotid artery blood flow and have a positive effect on blood lipid values.9-13 However, there are very few intervention studies, so the scientific evidence is weak.
The Role of Oral Health Personnel in the Prevention of Stroke
Even though true scientific evidence is lacking, it is reasonable to believe that maintaining good oral health diminishes the risk for cardiovascular events, including stroke. Cross-sectional, case-control, and observational epidemiologic studies show an association particularly between poor periodontal health and stroke. Furthermore, signs of periodontal pathogens have been detected in atheromatous plaques. For example, Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis trigger serum inflammatory reactions linked to increased stroke risk. Treatment of periodontal disease seems to reduce carotid artery intima-media thickness and atherosclerosis biomarkers and improves endothelial function. Thus, oral health personnel have a role not only in treating stroke patients but also in counseling and prevention. Maintaining satisfactory oral hygiene among patients who have survived stroke but are left with paresis of various degrees can be challenging. Especially in those cases, face-to-face instructing of the patient on the best way to clean the teeth and mouth mucosa is needed and valuable for quality of life.3-13
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13. Toregeani JF, Nassar CA, Nassar PO, et al. Evaluation of periodontitis treatment effects on carotid intima-media thickness and expression of laboratory markers related to atherosclerosis. Gen Dent. 2016;64(1):55-62.
Disclosure: The author reported no conflicts of interest related to this article.
About the Author
Jukka H. Meurman, MD, PhD
Department of Oral and Maxillofacial Diseases
Helsinki University Hospital