Re: B12 deficiency

Posted By CCF Neurology MD - AY on September 20, 1998 at 16:19:13:

In Reply to: B12 deficiency posted by Ann S. on September 20, 1998 at 15:12:32:






Dear Doctor,
I have written to you previously concerning a problem I had from waking up after surgery.When I went to Boston to have an EEG and to speak with another neurologist, he stated that the only thing that he saw that may have interfered or caused a problem with the anesthesia is my B12 level. He said it was low and suggested I get a shot. Upon researching the relationship between B12 and the nervous system I read that it has some control of neural function. I have since had more bloodwork and my B12 is low again. I am not a vegetarian. Could this deficiency be a contributory factor to the uncontrollable tics that I presented immediately following the surgery and the fact that my motor function was disassociated with my mental function? I understand the other problems that can result in the malabsorption of cyanocobalamin such as pernicious anemia,etc. Thank you for your time and sharing your knowledge.
Ann



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Thanks for your question.  Vitamin B12 deficiency can cause a number of
neurological impairments.  A more sensitive test to detect B12 deficiency
is a level of "methylmalonic acid (MMA)" - which is one of the precursors of
B12 metabolic pathways.  In a B12 deficiency, the MMA level is significantly
above normal.  In a patient that is just "borderline" B12 deficient, the
use of the anesthetic Nitrous Oxide can precipitate acute symptoms of
B12 deficiency: numbness in extremities, unsteadyness of gait, and weakness
in the lower extremities.  These symptoms typically appear 2-6 weeks
after a surgical procedure (involving Nitrous Oxide anesthesia) and resolve
quickly with Vit. B12 treatment.
The pathological changes of B12 deficiency occur in specific areas of the
spinal cord, namely posterior columns and lateral columns, hence explaining
the impairment in coordination of movements, and motor weakness, respectively.
Another test that you might mention to your treating physician for a full
evaluation of Vit. B12 deficiency is a "Schilling test" to assess the
proper absorption of dietary Vit. B12 by your gastrointestinal system.
I hope this information is helpful.  Best of luck.
This information is provided for general medical education purposes only.
Please consult your doctor regarding diagnostic and treatment options.