chapter 39 Neurologic Illnesses and Other Conditions
Treatment of patients with various neurologic illnesses is many times more enjoyable than treatment of any other dental patient because patients with these special needs are genuinely a joy to be around. On the other hand, this patient population may present more challenges for the practitioner. As in Chapter 38, references in this chapter are Internet sites* because they generally have the most up-to-date information available about these conditions.
Patients with mental disabilities often suffer more dental disease than other dental patients. Financial considerations may make it difficult to obtain dental treatment, so sometimes treatment is delayed or avoided altogether. Those with neurologic illnesses may be unable to understand the consequences of poor dental hygiene and irregular care, and they may be uncooperative during dental treatment. Many of these disabilities interfere with the ability of the person to perform the fine motor skills needed to properly care for his or her dentition.1
In dentistry, the typical long-term relationships we have with patients allow us to often see the patient’s degradation of mental function over time in Alzheimer disease (AD). The informed consent we obtain before performing dentistry may sometimes come from a person other than the patient. Determining the patient’s legal guardian may be difficult, but obtaining truly “informed consent” from that person is an absolute necessity.
The term Alzheimer disease dates back to a 51-year-old woman admitted to the Frankfurt hospital in 1901 with signs of dementia. At a meeting held in 1906, Dr. Alois Alzheimer reported on this patient. The title of his lecture was “Über eiene eigenartige Erkrankung der Hirnrinde” (On a peculiar disorder of the cerebral cortex). A few years later, presenile dementia was designated Alzheimer disease.3
AD is the most common cause of dementia in older people. It affects the parts of the brain that control thought, memory, and language. The cause of the disease still is unknown, and there is no cure.4 About 10% of patients older than 65 years have AD, and almost 50% of those 85 years and older have some signs of this disease. AD, however, is not necessarily a normal part of aging. Today, 4 million Americans have AD.5
People with AD may have trouble remembering recent events, activities, or the names of familiar people or things. As the disease progresses, symptoms are more obvious and become serious enough to cause those with AD, or more commonly their family members, to seek help. Later, people with AD may become anxious or aggressive, and they may wander away from home. Eventually, some patients will need complete 24-hour nursing care.4
AD is a slowly progressing disease, starting with mild memory problems and ending with severe mental damage. Currently, there are no curative therapies for AD, but the drug tacrine (also called THA or Cognex) may alleviate some symptoms. There are other medications that may help with sleeplessness, agitation, wandering, anxiety, and depression. This symptomatic therapy can make a very positive difference for some of those with AD.
Scientists believe that genetic factors may be involved in more than half of the cases of AD. For example, the protein apolipoprotein E (ApoE) appears to be involved, but the exact mechanism of action is not completely understood.6 AD is probably not caused by any one factor, however. It is likely that several factors in combination are involved.
The National Institute on Aging, the U.S. Federal Government’s lead agency for AD research, funds AD centers located throughout the United States. These centers carry out a wide range of research including studies on the causes, diagnosis, treatment, and management of AD.7
Local anesthesia can be used in this patient population without specific concerns. Patients not severely affected with AD may benefit from some sort of sedation for dental therapy. Inhalation sedation is an excellent choice for patients mildly affected with AD and others who retain the ability to cooperate for the sedation and dental procedure. Oral sedation is generally not the first choice in this patient population because of its inherent lack of safety related to the inability to slowly and properly titrate the drug. Intravenous (IV) sedation is a good choice exactly because of the ability to slowly and precisely titrate the drugs to a clinical end point. Moderate sedation in AD patients moderately or severely affected may lead to a decrease in cooperativeness as a result of an increase in mental clouding and mental confusion. For these patients, general anesthesia, possibly office based, may be the most appropriate therapy.
Pervasive developmental disorder (PDD) is a general category of disorders that are characterized by severe and pervasive impairment in several areas of development.9 Among others, autism falls under this general category of disorders. Understanding of autism has grown tremendously since Dr. Leo Kanner first described it in 1943.10 However, there is still no cure for the alterations in the brain that result in what we call autism. The more common other PDDs are listed in Box 39-1.11
Data from www.autism-society.org.
Common Pervasive Developmental Disorders (PDDs)
Pervasive developmental disorder—not otherwise specified (commonly referred to as atypical autism): A diagnosis of PDD-NOS may be made when a child does not meet the criteria for a specific diagnosis but there is a severe and pervasive impairment in specified behaviors.
Rett disorder: This is a progressive disorder that, to date, has occurred only in girls. There is a period of normal development and then a loss of previously acquired skills and loss of purposeful use of the hands replaced with repetitive hand movements beginning at the age of 1 to 4 years.
Autism is a developmental disability that is typically diagnosed early in life. Autism and autistic-like behaviors may occur in as many as 1 in 500 individuals.12 It is four times more prevalent in males than in females and is not related to racial, ethnic, or social groups. Family income, lifestyle, and educational levels do not affect the chance of autism’s occurrence. Those with autism typically have difficulties with communication, social interactions, and leisure or play activities. Occasionally, aggressive and self-injurious behavior is seen.11
Autism is a disorder with a continuum of presentations, some mildly affected and others severely affected. Two children, both with the same diagnosis, can act very differently from one another and have varying skill sets. Therefore there is no standard “type” or “typical” person with autism.
Current research links autism to organic alterations in the brain. There might be a genetic basis to the disorder, but to this point, a specific gene has not been directly linked to autism. If there is a genetic basis to autism, it probably involves interactions among several genes. Some patients with autism may appear to have mental retardation, a behavior disorder, problems with hearing, or even odd and eccentric behavior (Box 39-2).11
Data from www.autism-society.org.
Areas That May Be Affected by Autism
Communication: Language develops slowly or not at all; these patients use words without attaching the usual meaning to them; they communicate with gestures instead of words and have a short attention span.
Behaviors: The child may be overactive or very passive; he or she throws tantrums for no apparent reason, perseverates (shows an obsessive interest in a single item, idea, activity, or person), apparently lacks common sense, may show aggression to others or self, and often has difficulty with changes in routine.
Autism may coexist with other disorders that have neurologic effects, such as epilepsy, mental retardation, and Down syndrome (DS). It may also coexist with genetic disorders, such as fragile X syndrome, Landau-Kleffner syndrome, Tourette syndrome, or William syndrome.13–16 It is not unusual for those with autism to test low in IQ. About one in four will develop seizures at some point in their lifetime.11
The more severely affected the individual, the more difficulty he or she will have in cooperating with dental treatment. Autism itself infers no specific contraindications for using normal sedative and analgesic or anesthetic drugs. There are no physiologic changes of concern as a result of this specific condition. Patient cooperation may be problematic, however. Local anesthesia, inhalation, enteral, IV moderate sedation, and general anesthesia are all acceptable. As specific disease states are encountered secondary to autism (i.e., seizures), appropriate alteration to the anesthetic or sedative plan should be made.
Cerebral palsy (CP) is most often a developmental disability that manifests as an inability to fully control motor function, particularly muscle control and coordination (Box 39-3). CP is not communicable and is not a disease.17
Data from www.ucp.org.
Effects of Cerebral Palsy
Types of Cerebral Palsy