Medical researchers classify dementia into two broad categories, under which there are several known versions of the disease. These are cortical and subcortical dementias. Essentially, dementia in general is an impairment of your mental processes. It may affect how you reason, how well you remember and how clearly you think. The Cleveland Clinic states these problems must be severe enough to cause you difficulty dealing with daily life in order to be classified as dementia.
Alzheimer's Disease
The most widely known dementia is called Alzheimer's disease. It is a cortical dementia. It typically affects the elderly, but sometimes occurs in younger people. The most obvious symptom of Alzheimer's is a loss of memory. Typically, older people who suffer from it remember quite clearly events of their youths, but cannot remember what was just said or what they are doing. Sometimes, this can lead to wandering, which is why people with severe cases must be kept under observation. Other symptoms can include paranoia, communication problems, changes of personality and behaving inappropriately.
There is no cure, but there are medications that may be used to help clarify thinking. These include Aricept (generic: donepezil), Razadyne (generic: galantamine hydrobromide) and Exelon (generic: rivastigmine). Namenda (generic: memantine) also may be prescribed along with one of the others---known as cholinesterase inhibitors---for better effects.
Huntington's Disease
Huntington's disease is classified as a subcortical dementia. You may get it if someone in your family has had it. Along with bodily motions that may be uncontrollable, you also may experience disturbances of your emotional balance and a deterioration of your mental faculties. This disease, the Mayo Clinic reports, most often develops in middle age, but can affect younger people, too. When it does, those cases tend to be more severe. Symptoms may include changes of personality such as depression, anger and irritability. Your ability to reason and plan, as well as your memory, may be affected, and you may find yourself out of balance and clumsy.
Creutzfeldt-Jakob Disease
Creutzfeldt-Jakob disease also is known as CJD in the medical community. It is a fatal cortical dementia. While the Mayo Clinic reports CJD as similar to Alzheimer's disease, it begins and progresses far more rapidly. There is another form of the disease named in the 1990s called variant Creutzfeldt-Jakob disease that the Mayo Clinic states probably was caused by beef infected with mad cow disease or bovine spongiform encephalopathy. Like other forms of dementia, CJD may manifest with changes in personality, withdrawing from society, lapses in memory and concentration difficulties.
