Dementia was first documented by ancient Egyptian physicians around two thousand BC. Throughout antiquity, physicians identified this decline, yet this observation was not described as it is now until the late eighteenth century. In 1797, the French psychiatrist, Philippe Pinel coined the term dementia (démence). Dementia is derived from the Latin de meaning "out of" and mens meaning "the mind." Pinel's medical description of dementia was quite accurate; however, the name he used is not reflective of the disease process. Dementia is not being "out of one's mind." Dementia is the slow deterioration of mental capacities that is a direct result of a disease process in the brain. Dementia first emerges as mental changes, which may be subtle. Then, dementia further affects the brain so that bodily functions diminish. Unfortunately, this process can progress to death.

Once dementia is suspected, the next step is to determine what could be causing the symptoms. There are many different diseases that lead to dementia. Lewy Body disease, Pick's disease, alcoholism, HIV disease, head trauma, Parkinson's disease, Huntington's disease, Creutzfeldt-Jakob disease, vitamin B12 deficiency, among others all cause dementia. Some of these types of dementias affect the young, but the majority present later in life and vast majority of individuals with dementia are old. Also, some dementias are reversible when the underlying cause is treated, for example, when due to a deficiency in vitamin B12. However, the majority of patients with dementia have irreversible, but treatable forms. In the old, usually defined as greater than sixty-five years old, the two most common dementias, both of which are irreversible, are Alzheimer's disease and vascular dementia.

Alzheimer's disease

vascular dementia

Alzheimer's Disease

Alzheimer's is the most common recognized form of dementia. It accounts for about two-thirds of all cases of dementia and affects all ethnic groups. Also, it approximately affects men and women at the same rate.

The differentiation of Alzheimer's disease from other forms of dementia was first described in the early twentieth century. In 1907, the German psychiatrist Alois Alzheimer published a case study of a patient who had a progressive decline of mental functioning that lead to death. Dr. Alzheimer performed an autopsy on this demented patient and discovered structural changes in the patient's brain. Further study revealed other demented patients also had these structural changes at autopsy. Subsequently, because of his discovery, the illness was named after him, and his descriptions of brain pathology are still the definitive means to diagnose this type of dementia.

Currently, there are no means to conclusively diagnose Alzheimer's disease in the living. When dementia symptoms are noted, physicians rely on tests that exclude other causes. For example, older patients with depression or a deficiency in thyroid hormone may become forgetful. However, these patients usually have other signs of depression or thyroid disease, and the deficiencies in memory respond to treatment when it is directed at the underlying cause. Thus, in the absence of a direct cause for patients' symptoms, physicians make the diagnosis of Alzheimer's disease if it fits what is known about the clinical presentation.

Studies of the clinical presentation of Alzheimer's disease reveal that it affects the old and progresses slowly: the course of the illness ranges from five to twenty years. Most patients first develop symptoms in their seventies, though it may present early or later in life. These facts are imperative for diagnosis and shed light on what constitutes risks for developing the illness.

Old age is the most consistently associated risk factor for developing Alzheimer's disease. Aging is not the cause of Alzheimer's disease, but the risk of developing the disease increases as people age. Besides age, a family history of Alzheimer's disease is a risk factor for developing the illness. It is not known exactly how this predisposition to develop Alzheimer's disease is inherited, but one gene called ApoE/Î4 (which is a form of the alpolipoprotein E gene, which codes for a molecule that is involved in cholesterol transport) is associated with a higher risk for developing the illness. To note, having this gene just puts an individual at risk for developing Alzheimer's disease, and one can have this gene and not develop the illness. This suggests that other genetic factors are involved in the familial transmission of Alzheimer's disease, and other genes have been associated with the illness. Also, other factors have been associated with Alzheimer's disease, but do not have as high an association as old age and family history.

There are treatments that can slow the progression of Alzheimer's disease. As Alzheimer's disease affects the elderly, a treatment plan must include family members and other caregivers - so treatment extends the quality of life for all.

Vascular Dementia

Vascular dementia is the second most common type of dementia. It accounts for about ten to fifteen percent of dementia in the old and affects men at a higher rate then women.

The reason it affects men at a higher rate, is that vascular dementia is caused by damage to the brain by stroke, and men at are a greater risk for stroke. Men have higher rates of hypertension, hypercholesteremia, alcoholism, and smoking. All of these conditions are risk factors for stroke and subsequently vascular dementia.

Since strokes cause vascular dementia, the course of mental deterioration follows a "step-wise" fashion. In contrast to the gradual course of Alzheimer's disease, vascular dementia patients have abrupt periods of mental deterioration that are followed by periods of minimal deterioration. This course is a reflection of the sudden damage of the brain by stroke.

Currently, like in Alzheimer's disease there is currently no intervention to repair the brain damage in vascular dementia. However, there are preventative measures and treatments that are used to lessen the chance for further progression.