A chronic, inflammatory, immune-mediated disease of the central nervous system for which there is currently no cure. Multiple Sclerosis is a disease that results from individuals’ immune system attacking their central nervous system (brain, spinal cord, and optic nerves). The immune system damages myelin sheath (fatty substance surrounding the nerve fibers), Schwann cells, and the nerve fiber itself, disrupting the transmission of nerve impulses.60 This results in the damaged myelin forming scar tissue, commonly referred to as demyelination. Demyelination episodes are commonly referred to as relapses, exacerbations, attacks, or flare-ups. This leads to fatigue, weakness, numbness, incoordination, imbalance, vision loss, bladder dysfunction, bowel dysfunction, difficulty speaking, and cognitive impairment.61 Clinical signs and symptoms are summarized in Figure 16.
Epidemiology and Aetiology
Multiple sclerosis affects approximately 400,000 individuals in the U.S. and 2.3 million individuals worldwide.60 Diagnosis generally occurs between the ages of 20 and 50; however it can also occur in children.67 The average age of multiple sclerosis disease onset is 30 years; though, this can vary widely depending on the type of multiple sclerosis and one’s gender. The aetiology of multiple sclerosis is thought to be multifactorial; the interaction of a genetically susceptible individual with one of more environmental factors. The environmental factors include exposure to Epstein-Barr virus, sun exposure, Vitamin D, and smoking.61,68-72 It is important for the dental professional to understand that smoking has been shown to exacerbate symptoms of multiple sclerosis and increase risk of disease progression.73,74 Figure 17 provides additional statistics about this disease.
Patient Management and Oral Health Considerations for Multiple Sclerosis
Many multiple sclerosis symptoms can make it difficult to adequately care for the teeth (hand numbness, pain, spasticity, etc.) leading to dental caries, periodontal disease, and other conditions due to neglect.75 Oral self-care instructions should be based on the patient’s functional ability and values. It is also not uncommon for patients diagnosed with multiple sclerosis to experience oral cavity problems such as drug-induced xerostomia, bruxism, and malocclusion.75 Dysarthria, dysphonia, stuttering and dysphagia are also commonly associated with the disease.62 Depression is one of the more common symptoms of multiple sclerosis.62 The same oral conditions described in the depression section of this course are also seen in individuals diagnosed with multiple sclerosis. Extra-oral facial nerve pain, such as trigeminal neuralgia,66 is also common in individuals diagnosed with multiple sclerosis and may be an early symptom before a patient has the diagnosis of multiple sclerosis. Always note extra-oral findings of facial nerve pain in a patient’s dental record and immediately make physician referrals when patients report facial pain that cannot be explained.