Causes of Memory Problems
Most memory problems are not caused by Alzheimer’s disease. They are caused by depression, anxiety, stress, vitamin and hormone deficiency or adverse effects of prescription and over the counter medications. Memory problems that they cause can be reversed if properly and timely diagnosed.
What is “Dementia”?
The word “Dementia” refers to a broad category of brain diseases that cause a long term and often a gradual decrease in a person’s ability to think and remember, which affects that person’s day-to-day activities. Other symptoms of dementia often include emotional problems, problems with language and decreased motivation. Consciousness is usually not affected.
The most common type of dementia is Alzheimer’s disease which makes up 50% to 70% of dementia cases. Other common types include vascular dementia (25%), Lewy body dementia (15%), and frontotemporal dementia. Less common causes include normal pressure hydrocephalus, Parkinson’s disease, syphilis, and Creutzfeldt–Jakob disease. Diagnosis of dementia is usually based on history of the illness and cognitive testing with medical imaging and blood work used to rule out other possible causes. Efforts to prevent dementia include trying to decrease risk factors such as high blood pressure, smoking, diabetes, obesity and lack of exercise.
Diagnosis
Symptoms of various dementias are very similar and it is usually difficult to diagnose the type of dementia by symptoms alone. Diagnosis may be aided by brain scanning techniques. It has been shown that screening exams are useful in those people over the age of 65 with memory complaints.
Dementia and delirium
Cognitive dysfunction of a short duration is called delirium. Delirium can be easily confused with dementia due to similar symptoms. Delirium is characterized by a sudden onset, fluctuating course, a short duration (often lasting from hours to weeks), and is primarily related to a medical problem. In comparison, dementia has typically a long, slow onset (usually at least a year, except in cases of stroke or head trauma), slow decline of mental functioning, as well as a longer duration (from months to years).
Dementia and depression
Some mental illnesses, including depression and psychosis, may produce symptoms that must be differentiated from both delirium and dementia. Therefore, any dementia evaluation should include a depression screening such as the Neuropsychiatric Inventory or the Geriatric Depression Scale. It used to be thought that anyone who presented with memory complaints had depression and not dementia (because it was thought that those with dementia are generally unaware of their memory problems). However, recent evidence shows that many older people with memory complaints in fact have MCI, the earliest stage of dementia. Depression should always remain high on the list of possibilities, however, for an elderly person with memory trouble.
Neurocognitive Testing
Neurocognitive testing is one of the main tools for diagnosis of dementia. It usually consists of administration of a full battery of paper and pencil tests, often lasting several hours that help determine patterns of decline associated with varying types of dementia. Tests of memory, executive function, processing speed, attention, and language skills are relevant, as well as tests of emotional and psychological adjustment. These tests assist with ruling out other etiologies and determining relative cognitive decline over time or from estimates of prior cognitive abilities.
Role of an informant
Another approach to diagnosis of dementia is to ask an informant (relative or other supporter) to fill out a questionnaire about the person’s everyday cognitive functioning. Informant questionnaires provide complementary information to cognitive tests. Probably the best known questionnaire of this sort is the Informant Questionnaire on Cognitive Decline in the Elderly. The Alzheimer’s Disease Caregiver Questionnaire is another useful tool.
Laboratory tests
Routine blood tests are also usually performed to rule out treatable causes. These tests include vitamin B12, folic acid, thyroid-stimulating hormone (TSH), C-reactive protein, complete blood count, electrolytes, calcium, renal function, and liver enzymes. Abnormalities may suggest vitamin deficiency, infection or other problems that commonly cause confusion or disorientation in the elderly. The problem is complicated by the fact that these cause confusion more often in persons who have early dementia, so that “reversal” of such problems may ultimately only be temporary. Testing for alcohol and other known dementia-inducing drugs may be indicated.
Structural imaging
A CT scan or magnetic resonance imaging (MRI) is commonly performed, although these tests do not pick up diffuse metabolic changes associated with dementia in a person that shows no gross neurological problems (such as paralysis or weakness) on neurological exam. CT or MRI may suggest normal pressure hydrocephalus, a potentially reversible cause of dementia, and can yield information relevant to other types of dementia, such as infarction (stroke) that would point at a vascular type of dementia.
PET and SPECT
The functional neuroimaging modalities of SPECT and PET are more useful in assessing long-standing cognitive dysfunction, since they have shown similar ability to diagnose dementia as a clinical exam and cognitive testing. The ability of SPECT to differentiate the vascular cause (i.e., multi-infarct dementia) from Alzheimer’s disease, appears to be superior to clinical examination only.
Prevention
Many prevention measures have been proposed, including both lifestyle changes and medication although none has been reliably shown to be effective. Among old people who are otherwise healthy computerized cognitive training may improve memory; however it is not known if it prevents dementia. The degree of education or having been a manager in the past have been associated with a reduced risk for developing dementia.
Certain genetic variations in the APOE gene have been associated with a greater risk of developing Alzheimer’s dementia.
As with most medical conditions, a timely evaluation by a physician specializing in diagnosis and treatment of memory disorders is the best approach to assuring the optimal outcome of a memory problem.
© 2018 MoodNote LLC All Rights Reserved
