Neurology -- Correspondence for Juhasz-Pocsine et al., 68 (21) 1843-1850

Correspondence published:

Neurologic complications of gastric bypass surgery for morbid obesity: Donald Iverson, M.D., Melissa McKenzie, D.O. (19 September 2007)

Reply from the authors: Katalin Juhasz-Pocsine, Stacy A. Rudnicki, Robert L. Archer, Sami I Harik (19 September 2007)

Neurologic complications of gastric bypass surgery for morbid obesity 19 September 2007

Donald Iverson, M.D.,
Humboldt Neurological Medical Group, Inc.
2828 O’Neil Lane, Eureka, CA 95503,
Melissa McKenzie, D.O.
Send Correspondence to journal:
Re: Neurologic complications of gastric bypass surgery for morbid obesity

admin{at}hnmg.eurcoxmail.com Donald Iverson, M.D., et al.

We read Juhasz-Pocsine et al’s review of the neurologic complications of gastric bypass with interest. [1] As our group has also seen a number of neurologic complications of this procedure, we considered reporting our findings until this excellent review appeared. We have several questions.
Of the 12 patients with posterolateral myelopathy, five patients had low Vitamin B12 levels. Were B12 levels checked in the remaining seven? There was no report of methylmalonic acid (MMA) levels in any patient. Neurologically significant B12 deficiency can occur in patients with low-normal B12 levels (less than 300 pq/ml).[2] In those patients, deficiency is diagnosed by elevated MMA levels.[3]
The review also reports that five of eight patients tested had copper deficiency. Copper deficiency is seen in gastric bypass patients [4] and is a well-described cause of myelopathy. [5] Was the myelopathy in the four untested patients (patients #7,9,13, 16) attributed solely to B12 deficiency?
Patient #8 had both B12 and copper deficiency and many other patients had multiple metabolic abnormalities. Would the authors agree that the search for causes of myelopathy in these patients should not necessarily end when a single abnormality is identified? Besides B12, MMA, and copper levels, which tests would the authors consider to be routinely indicated in gastric bypass patients?
The improvement in all but one patient after “[correction of] their nutritional deficiencies via oral or parenteral supplementation” suggests that some of these patients may have had B12 or copper deficiency.
References
1. Juhasz-Pocine K, Rudnicki SA, Archer RL, Harik SI. Neurological complications of gastric bypass surgery for morbid obesity. Neurology 2007;68:1843-1850.
2. Stabler SP, Allen RH, Savage DG, Lindenbaum J. Clinical spectrum and diagnosis of cobalamin deficiency. Blood 1990;76-871-881.
3. Sumner AE, Chin MM, Abrahm JL, et al. Elevated methylmalonic acid and total homocysteine levels show high prevalence of vitamin B12 deficiency after gastric surgery. Ann Intern Med 1996;124:469-476.
4. Kumar N, Ahlskog JE, Gross JBJ. Acquired hypocupremia after gastric surgery. Clin Gastroenterol Hepatol 2004;2:1074-1079.
5. Kumar N, Gross JB Jr, Ahlskog JE. Copper deficiency myelopathy produces a clinical picture like subacute combined degeneration. Neurology 2004;63:33-39.
Disclosure: The authors report no conflicts of interest.

Reply from the authors 19 September 2007

Katalin Juhasz-Pocsine,
UAMS
4301 W. Markham slot 500 Little Rock, AR 72205,
Stacy A. Rudnicki, Robert L. Archer, Sami I Harik
Send Correspondence to journal:
Re: Reply from the authors

pocsinekatalinj{at}uams.edu Katalin Juhasz-Pocsine, et al.

We thank Drs. Iverson and McKenzie for their comments. All of our patients with posterolateral myelopathy were tested for Vitamin B12 (B12) serum levels and those with normal levels also had their methylmalonic acid (MMA) serum levels checked. Only one patient (#12) had elevated MMA with a high B12 level. This patient was given parenteral B12 replacement two months before her MMA level was checked. She also had multiple other nutritional deficiencies. In spite of high B12 levels, her myelopathy progressed.[1]
It is difficult to clinically differentiate between B12 and copper deficiencies as causes of myelopathy. We advise checking for both in patients with myelopathy after bariatric surgery. [5]
Multiple nutritional deficiencies often co-exist, including copper and B12, as seen in our series and well demonstrated in the case of patient #12. [1] Co-existence of copper and B12 deficiency may also lead to normocytic anemia, which reduces suspicion of these deficiencies.
We recommend testing for complete blood count, liver function tests, albumin, fat soluble vitamins, B vitamins, folate, cholesterol, calcium, magnesium, phosphate, copper, and iron levels in all bariatric patients with neurological deficits. [6] We also recommend cerebrospinal fluid investigations if the differential diagnosis mandates it.
References
6. Koffman BM, Greenfield LJ, Ali II, Pirzada NA. Neurological complications after surgery for obesity. Muscle Nerve 2006;33:166-176.
Disclosure: The authors report no conflicts of interest.