Dementia

August 18, 2011

Dementia, a devastating syndrome of multiple etiologies, probably affects up to 4 million people in the United States. The cost of the dementia syndromes to the United States has been estimated at up to $140 billion per year in caregiving costs, lost productivity, and medical and institutional care. Because the risk of dementia increases with age, and as the proportion of the U.S. population over 65 is rapidly increasing, dementia is emerging as a major public health problem of the 21st century. The dementia syndrome refers to a group of symptoms related to a sustained decrease in intellectual function from previous levels. Memory decline is always a part of this syndrome along with combinations of other impairments such as problems with judgment, language, recognition, or performing tasks. Personality change can also occur as a component. The dementia syndrome usually begins gradually, although in some cases it can occur suddenly, depending on the underlying cause. Some studies have suggested that dementia is more common in women than men, especially after age 85, while other studies have shown no gender differences.

There are multiple causes of the dementia syndrome, with over 60 disorders having been associated with dementia. However, the most common causes are: (1) Alzheimer’s disease, (2) vascular disease, and (3) diffuse Lewy body dementia. Other less common, but debilitating causes of the dementia syndrome include Parkinson’s disease, Huntington’s disease, and progressive supranuclear palsy. Potentially reversible causes of dementia include depression, medication effects, thyroid disease, vitamin deficiencies, and syphilis.

Alzheimer’s disease also known as dementia of the Alzheimer’s type (DAT) is the most common type of dementia, accounting for 50-60% of cases. The risk of DAT is age related with the risk over age 65 about 5-8% and the risk over age 85 increasing to 25-50%. Other risk factors for developing DAT include Down’s syndrome, history of head injury, and a family history of dementia. While the risk for DAT appears inherited in some cases, in other cases, there is no family history. The cause of DAT is not known, but is currently thought to be related to the genetically determined overproduction of abnormal brain proteins (“beta amyloid”) or abnormal brain protein processing and deposition. Microscopically, the brains of DAT sufferers show abnormal “plaques” and “tangles.” The impact of DAT on brain chemistry is a prominent degeneration of systems involving the neurotransmitter acetylcholine that is critical to intact cognitive function, although other neurotransmitters are also involved. The clinical picture of a typical patient with DAT is a description of a gradual decline that may not have been noted by family members until difficulties became obvious several years after onset (i.e., getting lost while driving, leaving the stove burners on).

Vascular dementia accounts for 10-20% of dementias. The major risk factor for this type of dementia is high blood pressure or hypertension. The clinical picture of vascular dementia differs from that of DAT; in vascular dementia, it is more common to see a stepwise decline. Treatment of high blood pressure or other cardiovascular disease can sometimes halt the progression of the illness but will usually not reverse symptoms. Often, a clue to vascular dementia is an association in time with a stroke and the onset of sustained memory problems. Strokes are not always obvious in terms of their symptoms and neuroimaging (such as magnetic resonance imaging or MRI) can detect strokes that were clinically silent.

Dementia with Lewy bodies (DLB) likely occurs in 15-25% of elderly patients with dementia. In DLB, patients have both cognitive impairment as well as symptoms of Parkinson’s disease (muscular rigidity, shuffling gait when walking, tremor in the hands, limited facial expression, and so forth). In addition, other symptoms such as falls, hallucinations, false beliefs (delusions), fluctuations in alertness or cognition, as well as fainting episodes may be present. Importantly, patients with DLB are very sensitive in terms of side effects to medications called neuroleptics or antipsychotics which are often used to treat behavioral symptoms in dementia.

Behavioral or neuropsychiatric symptoms commonly occur in dementia of all types and include depression, apathy, agitation, delusions, hallucinations, and sleep problems. A recent study found that 80% of participants exhibited at least one of these symptoms at some point after the onset of the memory disturbance. These symptoms, as opposed to the core cognitive symptoms of dementia, tend to be the ones that create problems for patients, families, and caregivers, and can lead to earlier placement in nursing homes.

The assessment of a person suspected of having dementia should include careful history, physical/neurological examination, as well as selected laboratory testing. On examination, focal neurological problems should be identified and the patient should be screened for depression as well as memory problems. The latter is usually screened for with the Mini-Mental State Examination (MMSE), a cognitive screening test that can be easily performed by physicians during an office visit. Importantly, the MMSE neither confirms nor rules out the presence of dementia; however, scores below a certain cutoff indicate the need for further workup and attention. Laboratory screening for thyroid disease and vitamin B12 deficiency is also recommended. Imaging of the brain, such as a noncontrast computerized tomography (CT) or MRI scan, is often appropriate. Neuropsychological testing is a helpful adjunct both to examine patterns of cognitive impairment that may be helpful to distinguish among the types of dementia as well as to establish a baseline of cognition for the individual patient.

Treatment of dementia includes both psychosocial and pharmacological treatments. Psychosocial treatments may include therapy to help the patient come to terms with their diagnosis as well as to work with the caregiver and family system in maintaining good activity levels for the patient and reducing the burden on caregivers. Referral to dementia support groups and resources is especially helpful for patients and their families. Pharmacological treatment includes treatment of: (1) the core cognitive symptoms as well as (2) secondary behavioral complications. Currently, the mainstay of treatment for the core cognitive symptoms in DAT (also used in DLB and, to a lesser extent, vascular dementia) are a class of drugs known as the “cholinesterase inhibitors” (donepezil, rivastigmine, galantamine). Notably, while these agents do not reverse the underlying illness of dementia, they slow its speed of decline and, in some cases, may improve problematic behaviors. Side effects of these medications include nausea, diarrhea, and loss of appetite. Vitamin E and selegiline may also reduce the rate of decline in patients with DAT. Ultimately, it is thought that actual disease modification in DAT will occur from preventing accumulation of abnormal brain protein (beta amyloid). For vascular dementia, treatment of underlying vascular risk factors (smoking, hypertension, diabetes, heart disease) is important. Treating the behavioral complications of all types of dementia is another very important part of treatment. Behavioral approaches can be effective in decreasing problem behaviors. Medications should be tailored to both the individual patient and the accompanying constellation of symptoms and may include: neuroleptics or antipsychotics (used to treat hallucinations, paranoia, or delusions), antidepressants (used to treat depression and anxiety), anticonvulsants (used for mood stabilization and for agitation), and trazodone or Desyrel (used for sleep difficulties and for agitation). Benzodiazepines (diazepam or Valium, alprazolam or Xanax, lorazepam or Ativan, and so forth) should generally be avoided or minimized due to concern of side effects (worsened cognition, falls) and especially of “paradoxical disinhibition” (reaction of agitation/worsened behaviors as opposed to the desired calming effect).

The vast majority of people with dementia are cared for at home by family or other informal caregivers.

Even when placement is needed in alternative living settings, family and informal caregivers continue to provide vital care to their loved ones with dementia. While caregivers can derive great satisfaction from this role, they also face chronic stress that can result in a variety of health problems. Caregivers need to cope with changes and losses in their relationship with the affected patient. The role of parent and child may be reversed, and the intimacy and companionship shared by spouses or parents may be lost. In some cases, caregivers may find themselves caring for family members with whom they have had a difficult relationship. Friends may not know how to behave or how to help. Siblings may disagree on treatments or living situations for the affected family member. All of these changes can contribute to the stress of caregiving. The warning signs of “caregiver stress” include exhaustion, insomnia, irritability, problems with concentration, physical health problems, impatience, low mood, excessive worry, feelings of isolation or loneliness, resentment, and guilt. Caregiver stress can be reduced by getting respite from caregiving including regular physical exercise, a healthful diet, learning relaxation techniques, getting regular medical care, and using respite opportunities to socialize and get rest. Support and education groups provide caregivers knowledge about particular conditions, helpful resources in the community, and techniques for handling difficult behaviors. Groups also provide a safe and encouraging place to express fears and celebrate successes. Future planning for legal, financial, and medical situations can also relieve stress and improve well-being.

SEE ALSO: Alzheimer’s disease

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