Alzheimer’s disease diagnosis 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 (thanks to www.alzforum.org for this link) as this will show abnormal glucose uptake and perfusion in some areas of the brain. The abnormalities look different in early Alzheimer’s versus late stage Alzheimer’s 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). In view of newer anti-aging medicine information, one should rule out heavy metal poisoning (mercury, lead and others) from pollution or longterm exposure at work (smelters etc.). If screening urine tests for mercury are positive, chelation therapy can be offered.
Alzheimer’s Disease Diagnosis
References:
1. OL Lopez et al. Neurology 2000 Dec 55(12):1863-1869.
2. K Yasojima et al. Brain Res 2000 DEC 887(1):80-89.
3. A Kontush et al. FreeRadicBiol Med2001Jan30(1): 119-128.
4. H Vanderstichele et al. Amyloid 2000Dec7(4):245-258.
5. Neely et al. Lipids 2000 Nov35(11):1249-1257.
6. RA Yokel Neurotoxicology 2000 Oct21(5):813-828.
7. Petanceska et al. Exp Gerontol 2000 Dec 35 (9-10):1317-1325.
8. MB Liddell et al. Brit J Psychiatry 2001 Jan 178: 7-11.
9. Sramek et al.ExpertOpinInvestigDrugs2000Apr9(4):899-915.
10.K Kosaka et al. Neuropathology 2000 March 20(1): 1-7.
11.V Haroutunian et al.Arch Neurol 2000 Aug57(8):1145-1150.
12. C Puckett et al. Am J Hum Genet 1991Aug49(2):320-329.
13. M Haltia Ann Med 2000 Oct 32(7): 439-500.
14. Ferri: Ferri’s Clinical Advisor: Instant Diagnosis and Treatment, 2004 ed., Copyright © 2004 Mosby, Inc.
15. Rakel: Conn’s Current Therapy 2004, 56th ed., Copyright © 2004 Elsevier
16. The 50th Annual St. Paul’s Hospital Continuing Medical Education Conference for Primary Physicians, Nov. 16 – 19, 2004
