SanderFridman, psychiatry, Forensic Psychiatric Program of the Federal University of Rio de Janeiro - Rio de Janeiro - Brazilsander_fridman@hotmail.com
Submitted July 08, 2001
Wang et al question the
laboratory criteria for establishing B12 or folate deficiency.
The high levels of folate considered to be already pathogenetic (10
and 12nmol/L) are quite alarming since, in our experience, levels quite
lower than that are frequent and are generally untreated.
On the other hand, B12 researched levels by Wang et al were not
accordingly high, since literature indicates peripheral and central
neuronal degenerative pathology responsive to B12 supplementation therapy
with levels of B12 as high as 350pg/ml. [1]
Wang et al reinforce the importance of not expecting
enlarged erythrocites before checking for cobalamine and folate
levels in patients with neuropsychiatric symptoms in general - not only dementia symptoms.
Rieder and Wang's discordant points of view about the meaning of low B12 and folate levels in the further development of Alzheimer Dementia
may be due to Wang's overlooked exclusion criteria to DSM-III-R
diagnosis of "Primary Dementia of Alzheimer Type" . It is excluded by
definition in the presence of low B12 and/or low folic acid.
Clinical diagnosis of probable AD is based on the
presence of slowly progressive and diffuse cognitive losses together
with the improbablity of another possible cause
for the dementing process (like B12, folate, B1, Zinc deficit; sedative
drugs chronic intoxication; Lues, HIV, etc). Only then does the evaluator indicate the presence of an ongoing underlying Alzheimer
neuropathological process.
AD is considered by the DSM system as an "all
excluded" kind of diagnosis - the last one in the dementia hierarchy.
The problem is that the most repeated concept in DSM-III-R, which is
present in almost every dignostic category, is that "The mental
symptoms cannot be better explained by any other organic disease that
affects brain function", which elevates organic mental disorders to the
highest diagnostic hierarchy. In DSM-IV, it is the same. However, the DSM system
hasn't established--until now--what is considered a minimal organic
workup for anyone to seriously answer to that criteria.
Reference
(1)ROWLAND, LP: Vitamin B12 deficiency, malabsorption, and
malnutrition: Merrit's Textbook of Neurology 9th ed.
Williams & Wilkins 1995:945-951.
Wang et al question the laboratory criteria for establishing B12 or folate deficiency.
The high levels of folate considered to be already pathogenetic (10 and 12nmol/L) are quite alarming since, in our experience, levels quite lower than that are frequent and are generally untreated.
On the other hand, B12 researched levels by Wang et al were not accordingly high, since literature indicates peripheral and central neuronal degenerative pathology responsive to B12 supplementation therapy with levels of B12 as high as 350pg/ml. [1]
Wang et al reinforce the importance of not expecting enlarged erythrocites before checking for cobalamine and folate levels in patients with neuropsychiatric symptoms in general - not only dementia symptoms.
Rieder and Wang's discordant points of view about the meaning of low B12 and folate levels in the further development of Alzheimer Dementia may be due to Wang's overlooked exclusion criteria to DSM-III-R diagnosis of "Primary Dementia of Alzheimer Type" . It is excluded by definition in the presence of low B12 and/or low folic acid.
Clinical diagnosis of probable AD is based on the presence of slowly progressive and diffuse cognitive losses together with the improbablity of another possible cause for the dementing process (like B12, folate, B1, Zinc deficit; sedative drugs chronic intoxication; Lues, HIV, etc). Only then does the evaluator indicate the presence of an ongoing underlying Alzheimer neuropathological process.
AD is considered by the DSM system as an "all excluded" kind of diagnosis - the last one in the dementia hierarchy.
The problem is that the most repeated concept in DSM-III-R, which is present in almost every dignostic category, is that "The mental symptoms cannot be better explained by any other organic disease that affects brain function", which elevates organic mental disorders to the highest diagnostic hierarchy. In DSM-IV, it is the same. However, the DSM system hasn't established--until now--what is considered a minimal organic workup for anyone to seriously answer to that criteria. Reference
(1)ROWLAND, LP: Vitamin B12 deficiency, malabsorption, and malnutrition: Merrit's Textbook of Neurology 9th ed. Williams & Wilkins 1995:945-951.