Possible Relationship Between Early B-12 Deficiency Disease & PN

[Wayne__0]

  My question relates to the remote possibility that already diagnosed (emg & neurologist exam) peripheral neuropathy (PN) being caused by early B-12 deficiency.  Reason is that original Neurologist concluded that PN was most probably resulting from cholesterol-lowering drugs (that I was in the 2% who so react to - in my case - Lipitor).
  BUT, now having followed for some time your forum, I asked for an received blood test for B-12 deficiency because 1) mother had pernicious anemia and 2) so many references to PN do relate to lack of B-12 -- after diabetes and such things as excessive booze (neither of which apply).  B-12 test revealed "early stages" of deficiency (reading of 19.3 -vs- normal range of 8.5 to 13.5) and one shot of B-12 was administered immediately.  Felt good for couple of days -- more energy, better mental processing, but falling back to where was, and do not get another shot until next month.  Lower legs again feeling on and off like wrapped with metal spats (reveals my age - 67), but no pain (never have any since PN diagnosed -- my problem was foot drop and loss of sensorimotor nerves), difficulty walking straight all the time, would wander off to the sides.
  Being as apparently I am genetically predisposed to high cholesterol (last thirty years in 250 range, but with high HDL, which now dropping), really should be taking cholesterol-lowering drugs, but with the noted neurologist adamantly opposed (family practice MD not so upset), and due to the fact there is cause to believe that they cause PN (2% factor) and are known to cause myopathy (much larger percentage), it appears I am between rock and hard place.  (Neurologist stepped out, saying that he not sufficiently knowledgeable this field -- potential toxic reactions/causes for PN -- to stay with case and recommended I go to Mayo Clinic, Rochester, as they "..have the only game in town.")  Now, however, with B-12 factor involved, we have a new ballgame, or at least muddied waters.  PN association advises on their site to be aggressive in seeking solutions through early treament, such as is available.  I realize that identifying causes of PN very complex, but do you believe that there is a chance I could have both a toxic reaction to Lipitor and have B-12 deficiency, or that there more likely is a single cause?
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Wow. Complex problem. I'm not a neuropathy specialist, so I can't comment specifically about Lipitor. I am aware that the "statin" drugs can cause myopathy (muscle damage) but I don't know about the neuropathy.
I do know that there are a ton of possible causes for neuropathy. Neuropathy is a generic term - it just means damage to nerves, as opposed to other structures in the nervous system (nerve roots, spinal cord, brain, etc). Causes run the gamut from toxic/metabolic, infectious/inflammatory, hereditary, mechanical, vascular, neoplasm, etc. The number of different causes for neuropathy is mind-boggling. However, the number of causes which can be treated is somewhat less. This is why tests such as B12, thyroid, and a handful of others are ordered: they are looking for the treatable causes.
The first step in evaluating neuropathy (assuming the history and neurologic exam have been carefully done) is an EMG/NCS (electromyography and nerve conduction study). Done well, this test establishes the pattern of the neuropathy: what nerves affected, axonal vs demyelinating, etc. Then a set of blood tests may be ordered, knowing the relatively more limited number of causes of the subset of neuropathies defined by EMG.
For the B12 deficiency, it would be important to know if the B12 really was low or not. For borderline values, there is a set of confirmatory blood tests usually employed (I also repeat the B12 itself just to be sure). It won't hurt you to get B12 shots regularly, even if it is not low. But if there is a serious deficiency, you want to really know.
As a general neurologist (actually, a subspecialist in a different area), I can get a start on diagnosing neuropathy. But for really difficult cases I recommend you consult a neuromuscular specialist. At stake is whether you can or should continue to use medications essential to another aspect of your health, and an estimation of the risk involved. You want someone with enough expertise to be able to say with confidence that it's NOT the Lipitor if it really is not.
Certainly, Mayo is an excellent place and if it's close to you then you should go. If Cleveland is not too far, you are certainly welcome to come here, and our neuromuscular specialists are also top notch. There are a few other excellent places - other than CCF or Mayo, I'd check out a large university medical center and ask for their neurology department. Ask how many faculty members are in the department, and how many neuromuscular specialists they have. For CCF, the number is 800 223 2273, ext 4-5559 (neurology appointments).