ASSESSMENT OF NEUROMUSCULAR JUNCTION INTEGRITY IN PATIENTS WITH TYPE 2 DIABETES MELLITUS
Background:Diabetes Mellitus produces long-term damage and failure of various tissues, in particular, diabetes-induced neural damage. Changes of neuromuscular transmission would contribute to the progressive weakness in diabetic patients; Electrophysiological studies are of recognized use in the confirmation of alterations of neuromuscular transmission and helping to differentiate them from other conditions.
The current study was performed to evaluate the integrity of neuromuscular junction (NMJ) in patients with type 2 diabetes using repetitive nerve stimulation (RNS) technique and assessment of acetylcholine receptors antibodies in the serum.
Patients and Methods:This cross-sectional study involved 103 patients with type 2 diabetes mellitus. The entire subjects met certain inclusion and exclusion criteria to exclude other possible contributing factors of neuropathy. All subjects completed a pre-requested questionnaire, then physical and neurological examinations were done, routine nerve conduction study, repetitive nerve stimulation and assessment of acetylcholine receptors antibodies were performed.
Results:Among 103 patients with type 2 DM patients 56 of them were diagnosed as peripheral polyneuropathy however, the rest (47) their NCS result were normal, 11 (10.7%) of them showed positive decrement test, All those with positive decrement test they have also peripheral polyneuropathy, serum acetylcholine receptor antibody test was negative in all the participants (those with positive and negative decrement test).
Conclusions:This preliminary study implies that type 2 diabetes contributes to the neuromuscular junction dysfunction. Further studies are indicated to explain the pathophysiology and mechanisms responsible for positive decrement test in type 2 diabetic patients.
2. Vinik A. Diabetic Sensory and Motor Neuropathy. N Engl J Med. 2016; 374:1 455 -64. DOI: 10.1056/NEJMcp1503948
3. Vinik A, Nevoret M-L, Casellini C, Parson H. Diabetic neuropathy. In: Poretsky L, Liao EP, eds. Acute and chronic complications of diabetes. Amsterdam: Elsevier. 2013;747-87.
4. Kimura J and Kohara N . Principles and Practice of Nerve Conduction Studies and Electromyography. 4th edition. 2013; Igaku-Shoin Lt.
5. Chumillas MJ, Cortes V. Electrodiagnosis in disorders of neuromuscular transmission. Revista de Neurologia. 2000; 30(1): 65-70.
6. Kimura J and Kohara N . Principles and Practice of Nerve Conduction Studies and Electromyography. 1st edition. 2003; Igaku-Shoin Ltd
7. Zivkovic S.A., Shipe C. Use of Repetitive Nerve Stimulation in the Evaluation of Neuromuscular Junction Disorders. Am J. END. Technol. 2005; 45:248-261.
8. Matthew P. Neurophysiological strategies for the diagnosis of disorders of the neuromuscular junction in children. Dev. Med & Child Neurol. 2008; 50: 328-333.
9. Jasper RD, Devon IR. Clinical Neurophysiology. 3rd edition. 2009; Oxford University press, Mayo Foundation for Medical Education and Research.
10. American Diabetes Association. American Academy of Neurology: Report and recommendations of the San Antonio Conference on Diabetic Neuropathy (Consensus Statement). Diabetes Care. 1988.11:592–597.
11. Preston DC, Shapiro BE. Electromyography and Neuromuscular disorder, clinical – Electrophysiologic correlation, Second Edition; Elsevier. US.2005. P.52-61
12. AAEM Quality Assurance Committee. Practice parameter for repetitive nerve stimulation and single fiber EMG evaluation of adults with suspected myasthenia gravis or Lambert-Eaton myasthenic syndrome: summary statement. Muscle Nerve.2001; 24:1236-38.
13. Preston DC, Shapiro BE. Electromyography and Neuromuscular disorder, clinical – Electrophysiologic correlation, Third Edition; Elsevier.US.2013.p. 530-48
14. Lo YL, Leoh TH, Dan YF, Tan YE, Nurjannah S, Ratnagopal P. Repetitive stimulation of the long thoracic nerve in myasthenia gravis: clinical and electrophysio1ogical correlations. J Neurol Neurosurg Psychiatry.2003; 74:379-81.
15. Shaw J.E, Sicree R.A, Zimmet P.Z. Global estimate of the prevalence of diabetes for 2010 and 2030. Diabetes Res Clin Pract. 2010.87 (1), 4-14.
16. Vincent AM, Callaghan BC, Smith AL, Feldman EL. Diabetic neuropathy: cellular mechanisms as therapeutic targets. Nat Rev Neurol. 2011;7: 573–583.
17. Marques MJ and Santo Neto H. Acetylcholine receptors and nerve terminal distribution at the neuromuscular junction of non-obese diabetic mice. Anat Rec. 2002; 267: 112–119.
18. Souayah N, Potian JG, Garcia CC, Krivitskaya N, Boone C, Routh VH et al. Motor unit number estimate as a predictor of motor dysfunction in an animal model of type 1 diabetes. Am J Physiol Endo-crinol Metab.2009; 297: E602–E608.
19. Garcia CC, Joseph GP, Kormakur H, Baskaran T, Lester GS, Nizar S, et al. Acetylcholinesterase deficiency contributes to neuromuscular junction dysfunction in type 1 diabetic neuropathy. Am J Physiol Endocrinol Metab.2012; 303: E551–E561
20. Wakata N, Nemoto H, Konno S, Nakazora H, Nomoto N, Sugimoto H, et al. Myasthenia Gravis and Diabetes Mellitus: A 35-year Retrospective Study. Intern Med. 2007. 46(9):557-9.