2.2 DEMENTIA
Dementia is a syndrome of impaired cognition caused
by brain dysfunction. It has been defined as “the development of multiple
cognitive deficits that include memory impairment and at least one of the
following: aphasia, apraxia, agnosia, or a disturbance in executive
functioning” (American Psychiatric Association, 1994). Dementia has become a major public health
concern because it leads to serious physical, functional, and psychologic
morbidity for the individual (Burns et al., 1991; Lyketsos and Rabins,
1994), because it shortens life expectancy (Kelman et al., 1994; Kukull et
al., 1994), and because caring for people with dementia exacts a heavy
toll on the care providers over the course of the illness (George and
Gwyther, 1986; Drinka et al., 1987).
Epidemiology
Most studies in the developed countries have reported
the overall prevalence of dementia to be between 5% and 10% of the elderly
(Canadian Study of Health and Aging Working Group, 1994; Evans et al.,
1989). In a largely illiterate rural population in northern India, Chandra
et al. (1998) found an overall prevalence rate of 0.84% and 1.36% for all
dementias; and 0.62% and 1.07% for Alzheimer’s Disease (AD) in population
aged > 55 years and > 65 years respectively. Neither gender nor
literacy was associated with the prevalence. These appear to be the lowest
prevalence of dementia reported from anywhere in the world. Universally,
the single largest subcategory of dementia is AD, with estimated size of
50% -90% of all dementias (Kukull and Ganguly, 2000).
Clinical features
Memory impairment is generally a prominent early
symptom of dementia. Individuals with dementia have difficulty learning
new material. In more severe dementia, individuals also forget previously
learned material, including the names of loved ones. Individuals with
dementia may have difficulty with spatial tasks, such as navigating around
the house or in the immediate neighborhood. Poor judgment and poor insight
are also common. In order to make a diagnosis of dementia, these cognitive
deficits must be sufficiently severe to cause impairment in occupational
or social functioning and must represent a decline from a previous level
of functioning. The order of onset and relative prominence of the
cognitive disturbances and associated symptoms vary with the specific type
of dementia.
Other symptoms of dementia include disinhibited
behavior, including making inappropriate jokes, neglecting personal
hygiene, exhibiting undue familiarity with strangers, or disregarding
conventional rules of social conduct. Suicidal behavior may occur in
mildly impaired individuals, who are more likely to have insight into
their deficits. Anxiety is fairly common, and some patients manifest
"catastrophic reactions," overwhelming emotional responses to relatively
minor stressors such as changes in routine or environment. Depressed mood
and sleep disturbances are common. Delusions of persecution and
misidentification, and hallucinations, most commonly in the visual
modality, could be present. Some patients exhibit sundowning, a peak
period of agitation during the evening hours. Dementia is sometimes
accompanied by motor disturbances, which may include gait difficulties,
slurred speech, and a variety of abnormal movements. Other neurological
symptoms, such as myoclonus and seizures, may also occur (American Psychiatric Association, 1997).
Assessment
The assessment of a patient presenting with symptoms
of dementia should address the patient's medical condition, including
functional status, cognitive status, other medical conditions, behavioral
problems, psychotic symptoms, and depression. The assessment should also
address the patient's support system, identify the primary caregiver and
assess the patient's decision-making capacity.
Assessment of Daily Function
Careful and competent
functional assessment identifies how to maximize patient autonomy (Kane,
et al., 1994). Functional assessment includes physical, psychological and
socioeconomic domains. Standardized assessment instruments can provide
information on the patient's capacity for self care and independent
living. Physical functioning is measured along a continuum and may focus
on basic Activities of Daily Living (ADL's) that include feeding, bathing,
dressing, mobility and toileting (Kane, et al., 1994; Katz, 1983). In
addition, Instrumental (or intermediate) Activities of Daily Living (IADL's)
assess more advanced self care activities, such as shopping, cooking, and
managing finances and medications. A useful informant-based tool to assess
dimensions of function is the Functional Activities Questionnaire (Pfeffer
et al., 1982).
Cognitive changes commonly associated with AD often
impact both the instrumental and eventually the basic activities of daily
living (Fitz and Teri, 1994; Small, et al., 1997). A baseline assessment
of functional abilities is important to determine a standard to which
future functional deficits can be compared. It will also provide realistic
treatment planning information and allow early supportive interventions to
be initiated (Ham, 1997). Assessment of a patient's living environment can
identify environmental supports that may be needed to maximize function,
ensure safety, and minimize caregiver stress.
Assessment of Cognitive Status
The cognitive status
of the patient should be assessed and documented using a valid and
reliable instrument, such as the Mini-Mental Status Examination (MMSE) (Folstein
et al., 1975). The MMSE can also be a useful predictor of ADL and IADL
impairment in patients diagnosed with dementia (Ford et al., 1996). The
MMSE is sensitive to formal education level and primary language of the
patient (Crum et al., 1993; Taussig et al., 1996; Small et al., 1997).
Valid bedside executive instruments, such as the Executive Interview and
an executive clock-drawing task, are better than MMSE in detecting
executive impairment
(Royall et al., 1992; Royall et al., 1998).
Neuropsychological testing is also helpful for
discerning cognitive functioning deficits of AD and other
neurological/psychological disorders (Cammermeyer and Prendergast, 1997;
Ritchie, 1997).
Assessment of Other Medical Conditions
Assessment of
the patient's medical condition should include obtaining information about
the client through structured interviews with the patient and a reliable
informant and office-based clinical assessment (Small et al., 1997).
Specific concerns include infectious disease, nutritional/feeding
difficulties, bowel/urinary disorders, mobility problems, cardiovascular
disease, pulmonary conditions, endocrine disease, coexisting neurological
disorders, and decubitus ulcerations (Ham, 1997; Fabiszewski, 1988).
Standard laboratory tests for a work-up of dementia
are directed toward identifying medical illnesses that can cause or
contribute to cognitive symptoms. The consensus of many reviews supports
the performance of a complete blood count, basic blood chemistries,
thyroid function tests, and a vitamin B12 level
(Knopman et al., 2001; Small et al., 1997). Imaging studies (computed
tomography or magnetic resonance imaging [MRI]) may identify conditions
other than neurodegeneration that could explain or contribute to the
dementia symptoms. Anatomic imaging reveals clinically unexpected lesions
in up to 5% of patients (Chui and Zhang, 1997; Knopman et al., 2001).
However, the greatest promise of MRI may lie in its ability to quantitate
the degree of brain atrophy.
Assessment of Behavioral Problems
The majority of AD patients
experience some form of behavioral problems during the course of the
disease (Small, et al., 1997; American Psychiatric Association, 1997). The
patient should be carefully evaluated for general medical, psychiatric, or
psychosocial problems that may underlie the disturbance (American
Psychiatric Association, 1997). Patterns in the behavior's frequency,
duration, potential triggers, and consequences should be documented.
Challenging behaviors have differing causes, emerge at different points in
the disease process, and present in a variety of manifestations (Cherry,
1997; Bolger, et al., 1994).
Psychotic symptoms are less common than the
behavioral disturbances identified above; however, there is increased
prevalence of psychotic symptoms as the disease progresses into the later
stages (Hirono, et al., 1998). Delusions, paranoia and hallucinations are
common and are of great concern since these symptoms are often linked to
aggressive, combative behaviors (Gilley, et al., 1997; Small, et al.,
1997; Koltra, et al., 1995). The Columbia University Scale for
Psychopathology in AD is a brief and effective instrument to assess
psychotic symptoms (Devanand, 1997).
Depression is underrecognised in older persons, and
depression is a common disorder in AD patients (American Psychiatric
Association, 1997; German, et al., 1985). Since administering assessment
tests for depression to AD patients is often challenging (Warshaw, et al.,
1995), gathering data from family members becomes especially important
(Jones and Reifler, 1994).
Regular Reassessments
Longitudinal monitoring of therapies
and regular health maintenance checkups are considered essential (Small,
et al., 1997), and ongoing care should include medication review,
treatment and monitoring of other medical conditions, treatment of
dementia by available medications if appropriate, monitoring of disease
progression, and referral to appropriate specialists (American Psychiatric
Association, 1997).
Frequency of visits is determined by a number of
factors including patient's clinical status, likely rate of change,
current treatment plan, need for any specific monitoring of treatment
effects, and reliability of skill of patients' caregivers (American
Psychiatric Association, 1997). It is generally necessary to see patients
in routine follow-up every six months, or sooner as indicated (American
Psychiatric Association, 1997; Small, et al., 1997). More frequent visits
(once or twice a week) may be required in the short-term for patients with
complex or potentially dangerous symptoms, or during administration of
specific therapies (American Psychiatric Association, 1997). Regular
appointments will also monitor dementia-associated behaviors such as sleep
disorders and agitation (Warshaw, et al., 1995), the development and
evolution of cognitive and non-cognitive psychiatric symptoms and their
response to intervention (American Psychiatric Association, 1997), provide
regular patient surveillance of cognitive and functional status, and
provide a forum for health promotion and maintenance activities (Small, et
al., 1997). |
