Which Occurs First in Patients with Type 2 Diabetes Mellitus? Central or Peripheral Neuropathy
Objective: To study the central and peripheral neuropathy by electrophysiological tests in type two diabetes mellitus patients (DM-2) before symptomatic peripheral neuropathy.
Methodology: DM-2 (n=30) and age- and sex-matched (n=30) healthy subjects (controls) with normal bilateral sural sensory nerve action potentials (SNAPs) were selected after informed written consent. Their 16-channel EEG records were transformed using Fast Fourier Transformation (FFT). EEG power spectra obtained were log-transformed and compared using student’s t-test.
Results: DM-2 without symptoms of peripheral neuropathy had low amplitudes of bilateral sural SNAPs in comparison to the controls though they were above the normal cut-off values of ≥ 4 μV. In EEG, DM-2 had more beta power (p<0.05) at midline Fz (24.77±11.58 vs. 12.26±11.55,), Cz (33.04±19.41 vs. 17.65±19.51,), and Pz (30.34±16.54 vs. 16.13±15.57,) and at other sites (Fp2, F8, F4, C4, T4, T6, P4, O2, Fp1, F7, F3, C3, T3, T5, P3, and O1) during eyes-close condition. Similar differences in beta power were seen in eyes-open condition. The delta power was more (p<0.05) in DM-2 during eyes-close condition at midline Fz (64.64±34.54 vs. 47.37±22.47), Cz (73.87±45.07 vs. 51.73±25.58), and Pz (66.13±36.84 vs. 44.15±19.68) and at other sites (Fp2, F8, C4, P4, O2, Fp1, F7, T3, T5, O1). Similar differences in delta power were seen in eyes-open condition. Alpha activities were more (p<0.05) in DM-2 at some sites during eyes-open condition.
Conclusion: Diffuse central neuropathy occurs along with the peripheral neuropathy in DM-2 as measured by the electrophysiological tests.
2. Fauci AS, Kasper DL, Longo DL, Braunwald E, Hauser SL, Jameson JL et al. Harrison’s principles of internal medicine. 17thed. New York: The McGraw-Hill Companies, Inc; 2008;2275-2276.
3. Christopher TK, Elizabeth RS. Cognitive dysfunction and diabetes mellitus. Endocrine Reviews 2008;29(4):494-511.
4. Misulis KE, Head TC. Basic principles of nerve conduction study and electromyography. In: Essentials of clinical neurophysiology. 3rd ed. Burlington: Butterworth-Heinemann, 2003;127-160.
5. Preston DC, Shapiro BE. Basic nerve conduction studies. In: Electromyography and neuromuscular disorders clinical electrophysiologic correlations. 2nd ed. Philadelphia: Elsevier Butterworth-Heinemann, 2005;25-45.
6. Mooradian AD, Perryman K, Fitten J, Kavonian GD, Morley JE. Cortical function in elderly non-insulin dependent diabetic patients. Behavioral and electrophysiologic studies. Arch Intern Med 1988;148:2369–2372.
7. Daniel JC, Kovatchev BP, Gonder-Frederick LA, Kent HS, Anthony Mccall, Kevin JG et al. Relationships between hyperglycemia and cognitive performance among adults with type 1 and type 2 diabetes. Diabetes Care 2005;28:71-77,
8. Lustman P, Anderson RJ, Freedland KE, de Groot M, Carney RM, Clouse RE. Depression and poor glycemic control: a meta-analytic review of the literature. Diabetes Care 2000;23:934-942.
9. Kawakami N, Takatsuka N, Shimizu H, Ishibashi H. Depressive symptoms and occurrence of type 2 diabetes among Japanese men. Diabetes Care. 1999;22:1071-1076.
10. Munshi M, Grande L, Hayes M, Ayres D, Suhl E, Capelson R et al. Cognitive dysfunction is associated with poor diabetes control in older adults. Diabetes Care 2006;29:1794–1799
11. Bruce DG, Casey GP, Grange V, Clarnette RC, Almeida OP, Foster JK et al. Cognitive impairment, physical disability and depressive symptoms in older diabetic patients: the Fremantle Cognition in Diabetes Study. Diabetes Res ClinPract 2003;61:59–67
12. Cukierman T, Gerstein HC, Williamson JD. Cognitive decline and dementia in diabetes–systematic overview of prospective observational studies. Diabetologia 2005;48:2460–2469
13. Curb JD, Rodriguez BL, Abbott RD, Petrovitch H, Ross GW, Masaki KH et al. Longitudinal association of vascular and Alzheimer’s dementias, diabetes, and glucose tolerance. Neurology 1999;52:971–975
14. Luchsinger JA, Tang MX, Stern Y, Shea S, Mayeux R. Diabetes mellitus and risk of Alzheimer’s disease and dementia with stroke in a multiethnic cohort. Am J Epidemiol 2001;154:635-641
15. Ott A, Stolk RP, Hofman A, van Harskamp F, Grobbee DE, Breteler MM. Association of diabetes mellitus and dementia: the Rotterdam Study. Diabetologia 1996;39:1392-1397
16. Peila R, Rodriguez BL, Launer LJ. Type 2 diabetes, APOE gene, and the risk for dementia and related pathologies: the Honolulu-Asia Aging Study. Diabetes 2002;51:1256-1262
17. Gibbs FA, Williams D, and Gibbs EL. Modification of the cortical frequency spectrum by changes in CO2, blood sugar and oxygen. J. Neurophysiol 1940;3:49-58
18. John R. Hughes. Names of rhythms or patterns. In: EEG in clinical practice. 2nd ed. Boston: Butterworth-Heinemann; 1994;15-18.
19. Grigsby AB, Anderson RJ, Freedland KF, Couse FE, Lustman PJ. Prevalence of anxiety in adults with diabetes: a systematic review. J PsychosomRes 2002;53:1053-1060.
20. Collins MM, Corcoran P, and Perry IJ. Anxiety and depression symptoms in patients with diabetes. Diabet Med 2009;26:153-161.
21. Khan KA, Lalani S, Dhanani R, Iqbal SA, Rafique G, White F. Anxiety and depression among outpatients with type 2 diabetes: A multi-centre study of prevalence and associated factors. Diabetology& Metabolic Syndrome 2010;2:72
22. Peyrot M, Rubin RR. Levels and risks of depression and anxiety symptomatology among diabetic adults. Diabetes Care 1997;20(4):585-590.
23. da Silva NE, Lopes F. The Normal EEG of the Waking Adult. In: Electroencephalography: Basic principles, clinical applications, and related fields. 5th Ed. Pennsylvania: Lippincott Williams & Wilkins, 2005;168-192.
24. Duffy FH, Iyer VG, Surwillo WW. The normal EEG. In: Clinical electroencepahlography and topographic brain mapping. New York: Springer-Verlag 1989;99-134.
25. Duffy FH, Iyer VG, Surwillo WW. Abnormal EEG pattern. In: Clinical electroencephalography and topographic brain mapping. New York: Springer-Verlag 1989;135-189.