Alzheimers Disease Diagnosis

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[edit] Alzheimers Disease Diagnosis

The diagnosis of Alzheimers is best left to a neurologist. The neurologist will exclude a host of other neurological diseases that can sometimes mask as Alzheimers disease such as brain infarcts, subdural hematomas and other illnesses. The physician will do blood tests to rule out treatable causes of dementia such as vitamin B12 deficiency (=pernicious anemia), hypothyroidism and others.

CT and MRI scans are useful to exclude other brain disease, but in Alzheimers these scans are normal. For research purposes a PET (positron emission tomography) scan would be desirable as this will show abnormal glucose uptake and perfusion in some areas of the brain. The abnormalities look different in early versus late stage disease.

In this particular PIB-PET scan study the researchers were able to use color shades where the normal PET scan shows blue and purple colors whereas Alzheimers patients show green, yellow and red color shades (results of a University of Pittsburgh/Pennsylvania study). This will be an invaluable tool for early diagnosis and for follow-up examinations where the effectiveness of some of the newer medications can be directly tested. According to information from a conference in Vancouver/BC (Ref. 16) the PIB-PET scan likely will be the gold standard in the near future for early diagnosis of Alzheimers, but also for monitoring the effectiveness of any treatment (during a discussion period with Dr. H. Feldman).

As mentioned under "Alzheimers research" (see Alzheimers link below), a cerebrospinal fluid tap by lumbar puncture could determine the level of one of the subtypes of amyloid peptide (the beta(1-42)amyloid peptide), which would be low in patients with Alzheimers disease (Ref. 4). However, this would again be more of a research tool at the present time. The diagnosis is largely based on clinical experience, interviewing and ruling out other diseases, coupled with the PIB-PET scan, if this is available (and affordable).

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Alzheimers, dementia and delirium

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