Dementia overview

Dementia Microchapters
Patient Information
Overview
Classification
Causes Alzheimer's Disease Parkinson's Disease Binswanger's Disease Dementia with Lewy bodies Thiamine deficiency Vascular dementia Marijuana abuse AIDS Neurosyphilis Normal pressure hydrocephalus Vitamin B12 deficiency Vitamin B6 deficiency
Differential Diagnosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor(s)-in-Chief: Vindhya BellamKonda, M.B.B.S [2]

Overview

Dementia (from Latin de- "apart, away" + mens (genitive mentis) "mind") is the progressive decline in cognitive function due to damage or disease in the brain beyond what might be expected from normal ageing.

Particularly affected areas may be memory, attention, language, and problem solving. Especially in the later stages of the condition, affected persons may be disoriented in time (not knowing what day of the week, day of the month, month, or even what year it is), in place (not knowing where they are), and in person (not knowing who they are).

Symptoms of dementia can be classified as either reversible or irreversible depending upon the etiology of the disease. Less than 10 percent of cases of dementia have been reversed. Dementia is a non-specific term encompassing many disease processes, just as fever is attributable to many etiologies. We do not routinely screen asymptomatic older adults for cognitive impairment. However, cognitive difficulty observed in a patient encounter, and family or patient concerns for memory and cognition, require thorough evaluation.

Without careful assessment, delirium can easily be confused with dementia and a number of other psychiatric disorders because many of the signs and symptoms are also present in dementia (as well as other mental illnesses including depression and psychosis). Screening for depression in patients with dementia is recommended because depression is a common treatable comorbidity that may also masquerade as dementia. Cognitive deficits may be pronounced and similar to dementia. However, both depressive symptoms and cognitive impairment respond to treatment with antidepressants, distinguishing these patients from those with Alzheimer disease and secondary depression. Late-life depression remains underdiagnosed and inadequately treated

Diagnosis

Laboratory testing

It includes: CBC, CMP, TSH, Vitamin B 12, serum Folate level, VDRL(in high risk patients)

CT

A CT scan is commonly performed, although this modality (as is noted below) may not have optimal sensitivity for the diffuse metabolic changes associated with dementia in a patient who shows no gross neurological problems (such as paralysis or weakness) on neurological exam. CT may suggestnormal 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. In most cases, MRI is preferred over CT because it is more sensitive for a broad range of potential pathologies while avoiding exposure to potentially harmful ionizing radiation.

MRI

A MRI is commonly performed, although this modality (as is noted below) may not have optimal sensitivity for the diffuse metabolic changes associated with dementia in a patient who shows no gross neurological problems (such as paralysis or weakness) on neurological exam. 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. Neuroimaging is also indicated when there are historical features or findings on physical examination suggestive of a subdural hematoma, thrombotic stroke, or cerebral hemorrhage

Brain Biopsy

it is reserved for younger patients and those with atypical clinical presentations in which a treatable cause of dementia (eg, inflammatory disorders such as vasculitis or multiple sclerosis) is considered. It has a very limited role in the diagnosis of dementia.

Other Imaging Findings

Recently, the functional neuroimaging modalities of SPECT and PET have shown quite similar ability to diagnose dementia as clinical exam . SPECT's ability to differentiate vascular type from Alzheimer disease types of dementias appears to be superior to clinical exam. Cerebral atrophy is common in patients with neurodegenerative dementia but also in normal aging. Atrophy may be generalized or regionally localized. Brain loses approximately 0.5 percent of its volume each year in normal aging, compared with 1 to 2 percent in MCI and 2 to 4 percent in dementia due to AD

Treatment

Primary Prevention

Prevention of dementia is the attempt to avoid developing dementia. Although no cure for dementia is available, there are many ways to decrease the risk of acquiring dementia in the first place, including both lifestyle changes and medication. "Use it or Lose it" might be applied to the brain when it comes to dementia. Intellectual activities help keep the mind in shape in the older days. Activities, such as reading, playing cards and board games and playing a musical instrument prevents dementia of both Alzheimer's and vascular dementia . The risk decreases proportionally to the frequency of activity. Family members or other informants who know the patient well are invaluable resources for providing an adequate history of cognitive and behavioral changes. A drug history is particularly important, as many medications may impact cognition in older patients.

Medical Therapy

Different options of medical therapy include: Cholinesterase inhibitors, N-methyl-D-aspartate (NMDA) receptor antagonist, Antioxidants, monoamine oxidase inhibitor, Vitamin E