Dementia

Dementia

The trauma of dementia is not the simple frustration of forgetting. The trauma includes the horror of being separated from one’s self, a self made up largely of one’s memories. A person without access to their memories – to their essential self – can become overwhelmed by the terror of being alone… Dementia brings new meaning to word alone.

Marilyn Mitchell, Dancing on Quicksand, 2002.

Dementia is a pervasive deterioration of intellectual ability that occurs over an extended period of time. Memory loss is the symptom most common in dementia and is typically the first cognitive change noticed by patients and families. Dementia also affects an individual’s: orientation to place and time; language functioning; ability to think abstractly and solve problems; power to evidence good judgment; visual and spatial ability; and personality.

Causes of Dementia

Dementia is often categorized according to the disease that is suspected of causing it. Though the causes of dementia are often difficult to determine, each disease process can result in slightly different symptoms. (Think of this like a pattern of cold symptoms: three people may have the same cold symptoms, but one person’s symptoms are causes by a virus, one by a bacterial infection, and one by allergies. These are all different causes of the same syndrome, or group of symptoms. Sometimes the treatment will be the same – a decongestant, for example – and sometimes the treatments will be difference – antibiotics, for example, used for bacterial infection only).

Common types of dementia are noted below. (Details are provided about only the most common causes).

Treatable Dementias

  • Toxic, from alcohol, drug, or heavy-metal exposure
  • Metabolic, as may be caused by thyroid disease or vitamin B-12 deficiency
  • Depression-related pseudodementia(dementia-like symptoms in the context of a depressive episode)
  • Medication-induced, the most common cause of reversible dementia in the elderly if detected early

Irreversible Dementias

  • Degenerative, including:
    • Alzheimer’s disease(AD) is the most common cause of dementia, representing 60 to 70 percent of all cases of dementia (Reuben, et al., 2001). The evidence is mixed, but early studies indicate that a specific gene, apolipoprotein E serum lipoprotein (APOE), may account for 10 to 40 percent of all cases of AD (Plassman & Breitner, 1996; Evans, et al., 1997). The gene appears to be responsible for early-onset AD (ages 50-75). Women with the APOE gene are at higher risk of contract AD than men are (Henri, 1998). This gene has not been found to be a risk factor for AD among African Americans (Froelich, Bogardus, & Inouye, 2001).
    • Parkinson’s disease is associated with the brain’s loss of a chemical called dopamine. Up to 40 percent of individuals with Parkinson’s disease develop dementia, with impairment primarily in executive functioning (planning, problem-solving, abstract thinking) and visual-spatial processing (Emre, 2003).
    • Dementia with Lewy bodies(DLB) is associated with abnormal structures (Lewy bodies) in the brain. It is less well understood than other forms of dementia. DLB is associated with a combination of symptoms of Alzheimer’s disease (confusion, attention problems) and Parkinson’s disease (motor problems), as well as visual hallucinations. Prevalence of DLB is estimated at between 15 and 35 percent of all cases of dementia, or approximately 0.6 percent of the general population over the age of 65 (Rahkonen, et al., 2003) 
    • Vascular dementia, which is caused by small strokes that decrease blood flow to the brain. Vascular dementia is the second most common form of dementia, representing 15 to 20 percent of all cases of dementia. The vascular damage leading to dementia may be categorized as one of the following:
      • Infectious, as may be caused by AIDS
      • Other – for example, conditions such as head injury, brain tumor, or subdural hematoma

Diagnosing Dementia

The diagnosis of dementia is based on criteria defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV; APA, 1994), which is the official listing and definition of psychiatric disorders by the American Psychiatric Association (APA). These criteria include:

1.      Deficits in short-term and long-term memory. Short-term memory is the retention of information over a span of a few minutes to a few hours, such as recalling what one had for breakfast today. Long-term memory is the retention of information over weeks to months, such as the name of the president of the United States, the place an individual was born, and names of children or grandchildren.

2.      The individual must have deficits in at least one of the following areas:

a.       Aphasia is the inability to understand or use language. A common problem is in identifying the names of familiar objects. Although many seniors complain that it is sometimes difficult to recall the right name or word (“tip-of-the-tongue”), individuals with AD are more often unable to produce the “stuck” words, even after a long delay.

b.      Agnosiais the inability to recognize and identify objects or persons despite having knowledge of the characteristics of the objects or persons. People with agnosia may have difficultly recognizing the geometric features of an object or face or may be able to perceive the geometric features but not know what the object is used for or whether a face is familiar or not.

c.       Apraxia refers to difficulty with physical movement despite normal physical functioning. Change in gait (walking) is one common example.

d.      Executive functioning includes problem solving, abstract thinking (recognizing, for example, that an apple and an orange are both fruit), organization, and judgment. Common examples of these deficits include having problems managing a checkbook or paying bills on time, not knowing what to do in an emergency such as a fire, or loss of ability to understand irony, sarcasm, or symbolic stories like parables.

3.      The deficits above significantly interfere with daily activities, or represent a significant deterioration from one’s previous level of functioning.

4.      No other medical condition, such as delirium or depression, accounts for the symptoms.

Additionally, in Alzheimer’s disease and some other forms of dementia, symptoms appear gradually and get progressively worse over time. In some forms of dementia, such as vascular dementia, symptoms may appear suddenly after a stroke or series of small vascular changes.

Because there are so many possible causes of cognitive problems and different areas of functioning are affected, psychiatrists, psychologists, and others use many different kinds of measures to diagnose the disease. After completing the following evaluations, an accurate diagnosis is likely:

  • Medical history: A physician should document current medical or physical conditions, onset and progression of memory complaints and behavioral changes, prescription drug intake, and family health history
  • Mental status evaluation: A patient should be assessed on his or her orientation to time and place and ability to remember, understand, communicate, and do simple calculations
  • Neuropsychological evaluation: This evaluation may consist of tests of memory, concentration, reasoning, visual-motor coordination, and language function
  • Physical examination: A patient will be evaluated on nutritional status, blood pressure, pulse, vision, hearing, a motor functioning
  • Magnetic resonance imaging (MRI) of the brain
  • Laboratory tests such as blood and urine tests: [Note that, while genetic research is related to Alzheimer’s disease is currently being conducted, genetic testing is not appropriate for diagnosis, since many people with Alzheimer’s disease do not have the genetic markers (Weiner et al., 1999)]
  • Psychiatric evaluation: Just as cardiologists are heart specialists, psychiatrists are brain specialists. If one is locally available, seniors should be referred to a geriatric psychiatrist. Otherwise, a referral should be made to a psychiatrist who is familiar with the diagnosis and treatment of dementia. Psychiatrists can also complete careful assessment of depression and other factors that may be causing the individual’s symptoms.

Prevalence of Dementia

The prevalence of dementia among seniors not living in institutions is 6 to 10 percent. At age 65, the prevalence of dementia is 5 to 7 percent, with the risk almost doubling ever five years of life until age 90, when rates level off to approximately 40 percent (Ficher, Schroppel, & Meller, 1996; Graves et al., 1996; Sadock & Sadock, 2000). Among nursing home residents, the rates of dementia are as high as 46 to 78 percent (Class et al., 1996; Magaziner et al., 2000). Dementia is the primary reason that many seniors are admitted to nursing homes.

Ethnicity

Rates of Alzheimer’s disease are comparable between Caucasians and African Americans, although African Americans have higher rates of vascular dementia. This difference has been attributed to a higher incidence among African Americans of hypertension, diabetes, and stroke (Heyman et al., 1991). Parkinson’s dementia is also less common among Caucasians than among African Americans (de la Mente, Hutchins, & Moore, 1989).

Gender

Research has been somewhat mixed, but large studies suggest that women and men develop AD at the same rate, although rates are higher for women over the age of 90 (Ruitenberg, Ott, van Swieten, Hofman, & Breteler, 2001). One explanation for this is that women live longer than men, thus they have inceased risk relatd to their age. Women have lower rates of vascular dementia than men (Ruitenberg, et al.).

Course of Dementia

The course of dementia depends on its cause. However, most dementias get worse over time. Exceptions to this pattern are dementias that, for example, are the result of a traumatic head injury or nonprogressive brain tumor. In these cases, the deficit remain relatively stable over time.

The above information was provided by the Society of Certified Senior Advisors (SCSA).