Dementia is defined as a clinical syndrome involving a sustained loss of intellectual functions and memory that results in dysfunction in daily living.¹ Dementia falls into two broad categories: reversible and nonreversible. AD is a type of nonreversible dementia, yet it is especially important to rule out reversible dementia early to attain the best possible outcomes. Reversible dementia accounts for less than 20% of all causes of dementia. One particular disorder, depressive pseudodementia, is an example of a readily treatable reversible dementia. This alteration in cognitive function is more closely related to the underlying depression than to a true neurological impairment. It is a challenge to diagnose because one third of clients with dementia also have co-existing depression. Other examples of potentially reversible dementia include neoplasms; autoimmune disorders such as multiple sclerosis and disseminated lupus erythematosus; toxins such as those incurred with alcoholism; infections; trauma such as subdural hematoma; nutritional disorders such as vitamin B12 deficiency; and specific drugs or polypharmacy. Many categories of drugs may contribute to or cause dementia, including anticholinergics, digoxin, steroids, and drugs used in the treatment of Parkinson’s disease, anxiety, ulcers, and cardiovascular disease.

Nonreversible dementias fall into four broad categories: degenerative diseases of the central nervous system, vascular disorders, trauma, and infections. AD, a neurodegenerative disease, accounts for about two thirds of dementia in the geriatric population.¹ It was first described by Alois Alzheimer, who reported on a 56-year-old female who presented with a rapidly progressive memory loss of 5 years’ duration and delusions about being killed. At the time of her institutionalization she had great difficulty reading, writing, naming, and acquiring new information with the backdrop of a totally normal neurological exam. Upon autopsy her brain showed atrophy, and Bielschowsky silver staining revealed neuronal changes now called “neurofibrillary tangles,” and “miliary foci” now known as senile or neuritic plaque. Alzheimer noted the presenile nature of the dementia, and his name lives on with his early diagnosis.²

AD is considered to be the most common dementia, with nearly 10% of the population older than age 65 being affected.² It is suggested that 7.1% of all deaths in 1995 were attributable to AD, which places it on par with cerebrovascular disease as the third leading cause of death. The prevalence of AD doubles every 5 years beyond age 65 and affects approximately 4.5 million Americans. By 2050, it is estimated that some 13.5 million Americans will have AD. Financial estimates put the annual national direct and indirect costs of caring for persons with AD at $100 billion.³ Thus interventions that improve quality of life and minimize expense can play a significant role in the treatment of this disease.

Research has shown an increased risk of AD with first-degree relatives, and recently several genes have been directly linked. Chromosomes 1, 14, and 21 all carry a potentially linked gene.² Chromosome 19 codes for the gene for ApoE, a plasma protein better known for triglyceride and cholesterol transport. Those individuals who carry the ApoE E4 allele have an estimated risk of developing AD of 45% to 60%. This is a fruitful area of research, and future efforts will undoubtedly uncover other genetic links.²

Assessment of Alzheimer’s Disease

Physicians list five required areas in the initial assessment of AD ⁴:

1. Instrumental activities of daily living (IADL)

2. Cognition, most commonly assessed using the Mini Mental State Examination (MMSE)

3. Co-morbid medical conditions

4. Disorders of mood and emotion

5. Caregiver status

Assessment of IADL determines the client’s ability to perform the complex tasks necessary for independent function, such as the ability to use the telephone, travel alone, shop, cook, take medication, and manage money. Clients are scaled as fully independent, need assistance, or dependent in all areas.⁴ As an example, Robert exhibits deficiencies in IADL because he requires assistance managing finances and remembering to change from his pajamas to daytime clothing in the morning. IADL assessment also revealed dependence in traveling secondary to his known history of getting lost while driving in familiar places.

The Mini Mental State Exam (MMSE ⁵) scales an individual’s neurocognitive function in areas such as orientation, immediate and delayed recall, attention, naming, following a command, reading, and writing. The results are 24 to 30 (maximum score is 30) as normal, 20 to 23 as mild, 10 to 19 as moderate, and 1 to 9 as severe. A score of 23 or less places an individual at likely risk of a neurocognitive deficit and is suggestive of AD, although additional testing and evaluation to discriminate the type of dementia are recommended.^4,⁵ Robert’s score on the MMSE was 22 out of a maximum score of 30 as a result of lost points in the areas of orientation, immediate recall, naming, and attention.

The client in this case has minimal co-morbid medical conditions except for mild insomnia, which may be related to the AD, benign prostatic hypertrophy, and a lumbar muscle strain. Some concern exists regarding the use of Benadryl, an antihistamine, also classified as an anticholinergic, because it may worsen the symptoms of dementia. Geldmacher and Whitehouse ⁶ report that many commonly used drugs such as analgesics, anticholinergics, antihypertensives, psychotropics, and sedative-hypnotics can interfere with cognition, and so discontinuing this medication was indicated for Robert. Robert’s risk of vascular dementia from stroke is very low because he has no history of hypertension or coronary artery disease and denies any mood alterations. These findings help to minimize the diagnosis of pseudodementia, in which clients are aware of a slowing of cognition but are often unaware of their own depressive symptoms.⁶

Robert is fortunate to have a healthy wife, secure financial status, and supportive family and friends. These areas of support will be called upon in many ways over the next few years. Specific scales exist to measure caregiver burden. AD ultimately has a more profound effect on the caregiver than the client. The client withdraws to another place in the past, while the caregiver often is rooted in the reality of the present. These scales measure the severity of caregiver stress associated with the common AD neuropsychiatric problems in addition to others such as sleep-wake cycle shifting. They may assist with caring for the caregiver as needed.⁴ Hallucinations, often of the visual variety, occur in up to 25% of clients with AD, and delusions affect about 50%. Symptoms of depression and anxiety occur in up to 40% of cases and may be the presenting signs of the disease. These psychological disturbances can wreak havoc on the caregiver and cause burnout.⁶

Laboratory Studies

Kawas ⁷ stresses the importance of the laboratory workup to ensure the absence of a reversible dementia in the newly diagnosed client. In addition to a careful history and physical and neurological exam, the client should have some type of brain imaging such as a non–contrast-enhanced computed tomographic (CT) scan or magnetic resonance imaging (MRI). Measurement of electrolytes and hepatic, thyroid, and renal functions in addition to vitamin B12 and folate levels is recommended. Testing for HIV and neurosyphilis (tertiary, irreversible form) is suggested based upon risk assessment. A lumbar puncture should be performed in clients with a history or signs of cancer or infection. Some physicians⁸ recommend a urinalysis and complete blood count. Abnormalities found through imaging and/or laboratory screening require further testing and assessment relative to the risk of reversible dementia. Indiscriminate testing has a low yield and large economic burden. In this case, Robert’s CT and laboratory tests were normal and a neurosyphilis test was negative.

Diagnosis

The definitive reference for classifying mental illness, including dementia, is the Diagnostic and Statistical Manual of Mental Disorders.⁹ Based upon Robert’s history, physical and cognitive testing, and laboratory/imaging assessments, the diagnosis of dementia of the Alzheimer’s type appears to be appropriate. He fits more closely to the mild stage in terms of his AD symptoms and is a candidate for behavioral and pharmacological intervention.⁸