What is Dementia?

Dementia - It's not always Alzheimer's

A diagnosis of mild cognitive impairment or of actual dementia may not always mean that one has Alzheimer's disease as there are over 80 forms of dementia. The definition of dementia is the gradual reduction of cognitive skills, memory, language usage and problem solving ability. Alzheimer's is a type of dementia and is the most common. However many of the AD symptoms mimic that of other types of dementia.

The term MCI (mild cognitive impairment) is the precursor of many forms of dementia. It is characterized by pronounced forgetfulness. Most of us as we age forget where we parked the car or where we put the house keys. This is due to the normal aging process as well as a lack of attention. With MCI this forgetfulness increases in frequency and severity over time. However, those diagnosed with MCI often stay at this level and their symptoms getting no worse.

As the dementia progresses over time, other symptoms such as physical dexterity will start to deteriorate as well. Although these are symptoms of AD, they are also hallmarks of other dementias as well. It is important to diagnose such conditions as accurately as possible as new drugs are developed which may be more effective in some types of dementia than in others.

The second most common from of dementia is multi-infarct dementia also known as vascular dementia. This is where a series of mini-strokes cause blood clots to block small vessels in the brain and destroy the tissue. Symptoms are similar to AD but often the damage is slight. The mental change is noticeable in a series of small steps but the decline is gradual than in AD.

Lewy Body Disease is another form of dementia with symptoms similar to AD. The disease gets its name from the deposits which are found in the brain after death which are named after the doctor who first discovered them. Lewy bodies are round deposits which contain damaged nerve cells. A precise diagnosis may be difficult as a scan may only reveal degeneration of the brain. Lewy bodies are typically only discovered by autopsy after death.

Parkinson's disease is characterized by low levels of the neurotransmitter dopamine. Symptoms include tremors and a general slowing of motor activity. It is only in the late stages of the disease that dementia is observed. Some Parkinson patients go on to develop AD just as some AD patients go on to develop Parkinson's disease.

Picks Disease or Fronto-temporal dementia - another form of dementia is very rare. It affects the frontal lobes and presents symptoms similar to AD. It is often difficult to diagnose and absolute certainty of the disease is usually not obtained until an autopsy is performed.

Creutzfeldt - Jakob disease - is caused by an infectious agent, most likely a virus. Again, symptoms are similar to those of AD. This is a fatal disease with death occurring usually after one year from initial diagnosis.

It is necessary to see a qualified physician who will take a comprehensive medical history, give a thorough medical, psychiatric and neurological exam, a mental status tests, visual imaging exams as well as various blood tests. It is with these tools that a proper diagnosis will hopefully be made and possible treatment modes can be evaluated.