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Home , Polyneuropathy

Reviews/Commentaries/ADA Statements COMMENTARY

Surgical Decompression for Diabetic Sensorimotor Polyneuropathy

iabetic neuropathy remains an un- this, patients have undergone these oper- sults may be no better than a number of met medical need. While scientific ations with neuropathy above the level of other noninvasive and less expensive in- D advances (1,2) have been made in the foot and hand. Additionally, the ac- terventions (15–18), all of which have understanding pathophysiology, the im- tual frequency of peripheral entrap- been claimed to achieve symptomatic pact on the clinical care of patients has ment in diabetic individuals is small. short-term improvement. been minimal, aside from symptomatic While some patients with DPN have Fourth, numerous centers have treatments for the pain that may accom- superimposed nerve entrapment syn- sprung up around the U.S. and the world pany diabetic sensorimotor polyneurop- dromes, these are the well-known sites of promoting their specially trained sur- athy (DPN) (3). Improved glucose control classic entrapments: the at geons and touting the benefits of these pro- is still the main recommendation for the the wrist causing classic carpal tunnel cedures (7). One can only guess the medical prevention and treatment of DPN, based syndrome, the at the elbow costs of these unproven procedures. on studies conducted over 10 years ago. causing at the elbow, Unfortunately, has been Ͼ Recently, two evidence-based reviews and the peroneal nerve at the fibular head here before. For 50 years, surgical pro- causing foot drop. Before this recent “ep- (4,5) for the treatment of diabetic neurop- cedures have been advocated for all sorts idemic” of nerve entrapments, entrap- athy have been published, which form the of diseases. In the 1950s, there were a ments at the other postulated sites have basis of the subsequent American Diabe- number of procedures for angina with been considered rare or even nonexistent many others to follow (19). While there tes Association position statement (6) on (11–13). the topic. are many explanations for the results from Second, the Tinel sign (14), which these types of , most important Into the apparent void of for was originally described in the setting of DPN, surgical decompression of multiple are the placebo effect and the natural his- nerve regeneration and not entrapment, is tory of the disorder. Only well-controlled, lower or upper limb is being advo- poorly standardized and lacks sensitivity cated as the treatment (7). The procedure randomized, double-masked, sham- and specificity. The proponents of the procedure, controlled clinical trials will is being utilized to treat symptomatic and subjective Tinel sign ignore the proven generalized DPN. This approach is based allow us to know whether these surgeries value of electrodiagnostic studies, an ob- are safe and effective for this indication— on a series of hypotheses. First, the signs jective test of nerve function. the same standard that any drug for DPN and symptoms of DPN are due to multiple Third, the American Academy of would have to meet. nerve entrapments. In the lower limb, (15) used an evidence-based What are we to do now? First, we be- foot numbness is ascribed to “entrap- criteria review for decompression lieve the findings of the American Acad- ment” of the peroneal nerve at both the for generalized DPN. Using standard pro- emy of Neurology’s evidence-based fibular head and the anterior tarsal tun- cedures to assess evidence, there was only review (15) should be strong evidence nel, the in the tarsal tunnel, one prospective trial. The utility of surgi- cal decompression for symptomatic dia- that the procedures should not be consid- and the sural nerve in the distal posterior ered care but, rather, subjected to further calf. In the upper limb, hand numbness is betic neuropathy received a grade IV rating; i.e., based on evidence from un- research until proven beneficial. Second, ascribed to entrapment of the ulnar nerve we strongly support trials to determine at both wrist and elbow, the controlled studies, case reports, or expert opinion. It was assigned a U grading, whether these surgical procedures are in the radial tunnel, and the median nerve beneficial. At this point, pilot trials should at the wrist. Second, these entrapments which is defined as “data inadequate or conflicting given current knowledge, be conducted to see whether there is rea- can be diagnosed by a trained examiner son to mount large phase 3 studies. The whose sole tool is the Tinel sign. Third, treatment is unproven.” Given that con- clusion, we believe that the treatment Centers for Medicare and Medicaid Ser- surgical “release” of these nerves will cor- cannot be recommended at this point in vices (CMS), which supported the recent rect DPN by decompressing the “com- time. A report on this topic by the Co- Lung Volume Reduction Surgery trial pressed” nerves. Fourth, special surgical chrane Collaboration will shortly follow. (20), is in the best position to support training is needed to be able to identify In the unblinded series of these pro- such trials and should have a great inter- these patients and operate on them. This cedures, pain relief as assessed by the op- est in doing so, given the widespread ap- series of hypotheses has spawned an en- erating surgeon occurred in 80–92% of plication of these unproven surgical tire industry. patients, some even occurring on the op- procedures among Medicare patients. There is much that is wrong with this erating table while recovering from the Third, we support further research into thinking. First, the distal neuropathy that anesthetic. Even more impressive are pa- the causes and treatment of DPN, an un- characterizes DPN is due to progressive tients reporting bilateral improvement met medical need. In conclusion, until such distal axonal loss (8–10). The proposed from unilateral procedures or patients time as definitive randomized trials are con- pathophysiological mechanism of entrap- with numbness or pain beyond the ana- ducted and the supporting evidence is ment cannot explain sensory or motor tomic distribution of the released nerves stronger, surgical decompression should symptoms or signs above the anatomic who improve after these procedures. If not be recommended for patients with dia- levels of the “entrapped” nerves. Despite only symptoms are being reported, the re- betic sensorimotor polyneuropathy.

DIABETES CARE, VOLUME 30, NUMBER 2, FEBRUARY 2007 421 Commentary

1 DAVID R. CORNBLATH, MD, FAAN 6. Boulton AJ, Vinik AI, Arezzo JC, Bril V, ogy. Neurology 66:1805–1808, 2006 2 AARON VINIK, MD, PHD, FCP, MACP Feldman EL, Freeman R, Malik RA, Maser 16. Khaodhiar L, Niemi JB, Earnest R, Lima C, 3 EVA FELDMAN, MD, PHD RE, Sosenko JM, Ziegler D: Diabetic neu- Harry JD, Veves A: Enhancing sensation 4 ropathies: a statement by the American ROY FREEMAN, MD in diabetic neuropathic foot with me- 5,6 Association. Diabetes Care ANDREW J.M. BOULTON, MD, FRCP chanical noise. Diabetes Care 26:3280– 28:956–962, 2005 3283, 2003 From the 1Department of Neurology, Johns Hop- 7. Dellon Institutes: relieving pain of dia- 17. Weintraub MI, Wolfe GI, Barohn RA, kins University School of Medicine, Baltimore, betic neuropathy and treatment of other Cole SP, Parry GJ, Hayat G, Cohen JA, Maryland; the 2Streltiz Diabetes Institute, Eastern peripheral nerve disorders [article online]. 3 Page JC, Bromberg MB, Schwartz SL, the Virginia , Norfolk, Virginia; the De- Available from www.delloninstitutes.com. Magnetic Research Group: Static mag- partment of Neurology, University of Michigan, Ann Accessed 10 November 2006 4 netic field therapy for symptomatic dia- Arbor, Michigan; the Department of Neurology, 8. Sugimura K, Dyck PJ: Multifocal fiber loss Beth Israel Deaconess Medical Center, Harvard betic neuropathy: a randomized, double- 5 in proximal in symmetric Medical School, Boston, Massachusetts; the De- distal . J Neurol Sci 53: blind, placebo-controlled trial. Arch Phys partment of Medicine, University of Manchester, 501–509, 1982 Med Rehabil 84:736–746, 2003 Manchester, U.K.; and the 6Department of Medi- 9. Dyck PJ, Thomas PK, (Eds.): Peripheral 18. Hamza MA, White PF, Craig WF, Gho- cine, University of Miami, Miami, Florida. name ES, Ahmed HE, Proctor TJ, Noe CE, Address correspondence and reprint requests to Neuropathy. 4th ed. Philadelphia, Saun- David R. Cornblath, MD, Meyer 6-181a, Johns Hop- ders, 2005 Vakharia AS, Gajraj N: Percutaneous elec- kins Hospital, Baltimore, MD 21287. E-mail: 10. Dyck PJ, Thomas PK (Eds.): Diabetic Neu- trical nerve stimulation: a novel analgesic [email protected]. ropathy. 2nd ed. Philadelphia, Saunders, therapy for diabetic neuropathic pain. Di- DOI: 10.2337/dc06-2324 1999 abetes Care 23:365–370, 2000 © 2007 by the American Diabetes Association. 11. Stewart JD: Focal Peripheral Neuropathies. 19. Leonard DR, Farooqi MH, Myers S: Res- 3rd ed. Philadelphia, Lippincott Williams toration of sensation, reduced pain, and ●●●●●●●●●●●●●●●●●●●●●●● & Wilkins, 2000 improved balance in subjects with dia- References 12. Dawson DM, Hallett M, Wilbourn AJ betic : a double- 1. Sullivan KA, Feldman EL: New develop- (Eds.): Entrapment Neuropathies. 3rd ed. blind, randomized, placebo-controlled ments in diabetic neuropathy. Curr Opin Philadelphia, Lippincott Williams & study with monochromatic near-infrared Neurol 18:586–590, 2005 Wilkins, 1999 treatment. Diabetes Care 27:168–172, 2. Brownlee M: The pathobiology of diabetic 13. Vinik A, Mehrabyan A, Colen L, Boulton 2004 complications: a unifying mechanism. Di- A: Focal entrapment neuropathies in dia- 20. Freeman TB, Vawter DE, Leaverton PE, abetes 54:1615–1625, 2005 betes. Diabetes Care 27:1783–1788, 2004 Godbold JH, Hauser RA, Goetz CG, Ol- 3. Vinik A, Ullal J, Parson HH, Casellini CM: 14. Nora DB, Becker J, Ehlers JA, Gomes I: anow CW: Use of placebo surgery in con- Diabetic neuropathies: clinical manifesta- What symptoms are truly caused by me- tions and current treatment options. Nat dian nerve compression in carpal tunnel trolled trials of a cellular-based therapy Clin Pract Endocrinol Metab 2:269–281, syndrome? Clin Neurophysiol 116:275– for Parkinson’s disease. N Engl J Med 341: 2006 283, 2005 988–992, 1999 4. Vinik AI, Maser RE, Mitchell BD, Freeman 15. Chaudhry V, Stevens JC, Kincaid J, So YT: 21. National Emphysema Treatment Trial Re- R: Diabetic . Dia- Practice advisory: utility of surgical de- search Group: A randomized trial com- betes Care 26:1553–1579, 2003 compression for treatment of diabetic paring lung-volume–reduction surgery 5. Boulton A, Malik R, Arezzo JC, Sosenko neuropathy: report of the Therapeutics with medical therapy for severe emphy- JM: Diabetic somatic neuropathies. Diabe- and Technology Assessment Subcommit- sema. N Engl J Med 348:2059–2073, tes Care 27:1458–1486, 2004 tee of the American Academy of Neurol- 2003

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