Dementia: A Focused Review

Dementia can also be caused by endocrine disorders. If hypothyroidism is left untreated, for example, dementia can appear, and aggressive thyroid replacement may not return a patient to his or her previous level of cognitive functioning. The dementia with untreated hypothyroidism is also accompanied by irritability, paranoia, and depression. Cushing disease and Addison disease may lead to dementia. Hypoparathyroidism is the most common cause of basal ganglia calcification with dementia. Hyperthyroidism and hyperparathyroidism may also lead to dementia.

Untreated vitamin B₁₂ deficiency can lead to dementia in the absence of anemia or megaloblastosis. Vitamin B₁₂ replacement may improve cognition, but dementia may still continue. High-dose vitamin B supplements do not slow cognitive decline in patients with mild to moderate Alzheimer dementia.¹⁴

Head trauma may cause dementia from diffuse axonal injury secondary to shearing forces, focal contusions, hemorrhages, lacerations, and hypoxic ischemia. Symptoms include anterograde and retrograde amnesia, deficiencies in encoding and retrieval of new information, disorganized thinking, poor concentration, and fluent aphasia.

Dementia pugilistica, a syndrome caused by repeated head trauma in boxers, leads to a clinical picture of dementia and ataxia. A study of retired National Football League players found that the incidence of diseases of memory (dementia, Alzheimer disease [AD], or other memory-related disease) was higher in retired players than in the general population.¹⁵ However, cognitive tests and neurological examinations were not completed, which significantly limits interpretation of these results.

A chronic subdural hematoma may be caused by mild head trauma in elderly patients and can lead to a clinical picture of dementia. Associated symptoms may include headache, slowed thinking, hemiparesis, change in personality, seizures, and aphasia. Any patient with a subdural hematoma must receive immediate neurosurgical evaluation. Surgical drainage may or may not be required, but an acute bleed can occur, and the pa-tient may have further neurological deterioration.¹⁶

Infectious processes can cause a clinical picture of dementia. Neurosyphilis can cause dementia even after 20 years from the time of infection. General paresis, a subtype of neurosyphilis, may present as a progressive dementia, changes in speech, irritability, grandiose delusions, and hallucinations.^5,17 The rapid plasma reagin test has a high false-positive rate and results may be negative in late syphilis. A fluorescent treponemal antibody absorption test may be a better tool for diagnosis.

HIV-associated dementia affects subcortical structures while sparing the cortex. Forgetfulness, poor concentration, and slowed thinking are early symptoms. Apathy and social withdrawal may arise, and psychosis occurs occasionally. Patients with AIDS may have infections, CNS malignancies, or systemic illness that may lead to cognitive impairment.

Toxins can cause a clinical picture of dementia. Long-term alcohol(Drug information on alcohol) use can lead to alcoholic dementia, which includes anterograde and retrograde amnesia. Alcoholic dementia is mild and slowly progressive; it is associated with impairments on initial letter fluency, fine motor control, and free recall.

Comprehensive treatment planning

Patients with dementia need a comprehensive treatment plan, including biological, psychotherapeutic, social, and family interventions (Table 4).

Biological interventions include treatment of any underlying medical disorders and the appropriate use of medications for target symptoms. Psychotherapeutic interventions can be generally divided into 4 categories:

• Behavior-oriented

• Emotion-oriented

• Cognition-oriented

• Stimulation-oriented

Although many psychotherapeutic interventions are commonly used in clinical practice, only a few of these interventions have undergone double-blind randomized evaluation.⁷

Social interventions include assessments of the patient’s living environment, his ability to drive, risk level for abuse and/or neglect, availability of daytime/nighttime supervision, and occupational therapy to ensure home safety. Services such as a home health aide, a house cleaner, and Meals on Wheels may be needed to assist with basic activities of daily living. A discussion about financial/estate planning, health care power of attorney/advanced care directives, and long-term–care facilities may be needed as the dementia progresses.

Family interventions to help prevent caregiver burnout include supporting family caregivers with psychoeducation, respite care, and referral to local support groups through national associations. A list of print and Internet resources that may be useful for those who care for patients with dementia is posted on www.psychiatrictimes.com in the online version of this article.

Table 5 highlights key clinical and neuropsychological features of certain diseases that may cause dementia. The following discussion focuses primarily on cognitive aspects.

Alzheimer disease

The most common cause of dementia in North America and Europe is AD; approximately 4 million persons in the United States have AD.¹⁸ Risk factors include increasing age, traumatic brain injury, reduced brain reserve capacity, limited educational/occupational achievement, cerebrovascular disease, hyperlipidemia, hypertension, athero-sclerosis, coronary heart disease, atrial fibrillation, smoking, obesity, and diabetes.