Please click on one of the subjects below for more more information about that subject. General Information "Probable" Alzheimer's Disease Laboratory and Blood Testing Vascular Dementia Lewy Body Dementia New Diagnostic Tests GENERAL INFORMATION     In 1907, Alois Alzheimer reported the first case of the illness that was named after him. The case he described was a 51- year- old woman with progressive cognitive decline and behavioral changes, associated with plaques and tangles in the brain. Today, more than 4 million Americans suffer from Alzheimer's disease. Over the next 50 years, by some estimates, the number of alzheimer cases is expected to triple. The annual cost of caring for demented patients in the United States is more than $100 billion.    Early and accurate diagnosis is critical to helping those with dementia. For example, there is evidence that progression of vascular dementia may be modified by risk factor management. Similarly, if alzheimer's disease is diagnosed very early, medicines such as Aricept and Reminyl can more effectively delay progression of the disease. "PROBABLE" ALZHEIMER'S DISEASE     The National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association (NINCDS-ADRA) has established guidelines to help diagnose alzheimer's disease.These guidelines define definite, probable, and possible alzheimer's disease. Probable alzheimer's disease is established by clinical examination and tests such as the Mini Mental State Exam(MMSE) or Clock Test. Other criteria include: two or more deficits in cognitive tasks, progressive memory loss,and no disturbance of consciousness. For example, sometimes delirium in the elderly is mistaken for alzheimer's disease. Delirium is a state where a patient may be only semi-conscious, and this state can be induced by pain, infection,dehydration, or drugs. Delirium usually clears up once the cause is pinpointed and altered. A diagnosis of probable alzheimer's disease is further supported if the patient also has language or motor difficulties,has impaired activities of daily living, and has a family history of alzheimer's disease. Alzheimer's disease may also be indicated if there are plateaus in the course of the disease. For example, the patient may seem better for a while, but then begins again to decline. Sudden onset of cognitive problems and memory loss is not characteristic of probable alzheimer's disease. Computerized brain scans, early in the illness often show little change from normal aged individuals. However, as the illness progresses,CT scans will show loss of brain cells. Patients with probable alzheimer's disease may also show gross changes in behavior such as agitation,delusions,hallucinations,and depression. Depression can complicate a diagnosis of alzheimer's disease. This is so because non-demented persons suffering from depression have difficulty concentrating and memorizing. These patients are usually aware that their depression interferes with their memory. On the other hand, most alzheimer patients are not likely to seek medical attention for memory loss;in fact medical attention is most often requested by caregivers. Possible alzheimer's disease is suggested when the course of cognitive decline is slow and gradual, and no primary medical cause for dementia can be found. Often,with possible alzheimer's disease, some other secondary disease process, with symptoms similar to alzheimer's disease, complicates an easy diagnosis of alzheimer's disease. Definite alzheimer's disease is diagnosed reliably only by autopsy. The presence of significant senile plaques and neurofibrillary tangles in the brain confirms the clinical diagnosis of alzheimer's disease. Studies have shown that trained clinicians can diagnose alzheimer's disease with about a 90% accuracy. LABORATORY AND BLOOD TESTING     Laboratory and blood chemistry profiles are important in the diagnosis of dementia. Systemic infections,revealed by blood chemistry, can cause delirium, and be mistakenly diagnosed as dementia. Similarly, a deficiency of Vitamin B12 can cause memory and cognitive loss,but this deficiency can be diagnosed by routine blood chemistry. Further, alterations in thyroid function can cause memory and cognitive problems, and this can also be diagnosed by laboratory work. Laboratory testing can also pinpoint whether dementia-like symptoms are caused by neurosyphilis or the HIV-virus. Some HIV-infected patients develop a dementia similar to alzheimer's disease. VASCULAR DEMENTIA     Although alzheimer's dementia is the most prevalent dementia, other dementias are important and may be confused with alzheimer's disease early on. Vascular dementia is probably the second most common form of dementia. Generally, vascular dementia is characterized by sudden onset of memory or cognitive problems, following occurrence of a cerebrovascular accident, CVA,(stroke).Multiple strokes may cause additive cognitive loss. CT or Magnetic Resonance Imaging can usually pinpoint areas of CVA, known as cortical infarcts. LEWY BODY DEMENTIAS     Another very important kind of dementia is parkinson dementia with Lewy Bodies. Some workers feel this dementia is as prevalent as vascular dementia. In this dementia, there is general slowness of thought and actions( referred to as bradyphrenia). Delusions and hallucinations are common.Symptoms fluctuate markedly. Rigidity and gait changes are more common than tremor. Sometimes rigidity and gait changes occur in alzheimer patients, but when they do, they tend to occur very late in advanced stages of the disease.If rigidity and other parkinson-like signs occur early in the course of Alzheimer's disease,some workers regard that as a Lewy Body type of Alzheimer's disease. NEW DIAGNOSTIC TESTS     Pharmaceutical companies are scrambling to find an effective,safe diagnostic test for alzheimer's disease. The market for such a test would be enormous, estimated , conservatively ,at $200 million yearly. Several diagnostic tests have been developed by three biotechnology companies. Nymox Corporation has found that Alzheimer patients have high levels of a protein, called neural thread protein, in brains, blood, urine, and cerebrospinal fluid. Nymox has developed an antibody technique that detects neural thread protein in urine samples. Their test, called AlzheimAlert,is performed on urine specimens sent to a special certified laboratory. The urine test, according to company statistics,is 80% sensitive and over 90% specific. MitoKor corporation has found that mitochondrial DNA, encoding for cytochrome c oxidase, is altered in alzheimer patients. The alteration is a deletion of a nucleotide pair at base position 4977. MitoKor, based in San Diego, has licensed its alzheimer assay, Mito-Load, to SRL Inc, of Japan, for use in clinical assay work there. Athena Diagnostics, in Worcester, Massachusetts, has developed several diagnostic assay kits for alzheimer testing. One of their assays detects the presence of the Apolipoprotein E4 allele. Apolipoprotein E is involved with cholesterol transport and there are three genetic isoforms, E2,E3,E4. The E4 isoform has been found to be a significant risk factor for Alzheimer's disease, especially after age 65. Athena Diagnostics also has an assay kit to detect two proteins called tau and amyloid beta 1-42. Research work in the last few years has shown that in alzheimer patients, tau protein elevates in the cerebrospinal fluid, at the same time that levels of amyloid beta 1-42 decline. The two tests, used together, can reliably discriminate who has alzheimer's disease and who doesn't. Athena Diagnostics also offers a test for presenilin-1, which is a protein that is altered in early- onset alzheimer's disease, that tends to run in families. Early-onset, familial, alzheimer's disease strike its victims when they are in their 40's or 50's. Early- onset alzheimer's disease tends to have a virulent course, and persons afflicted with this form may decline very rapidly, compared to those persons who get alzheimer's disease after age 65. So far, diagnostic kits have not yet replaced good clinical judgement as a way to diagnose the disease. Most researchers feel that diagnostic kits will help increase the accuracy of clinical judgements. This site is a member of the Medical Banner Exchange