Diabetic neuropathy

Toronto Expert Panel on Diabetic Neuropathy diagnostic criteria for distal symmetric polyneuropathy (DSPN)[3]Dyck PJ, Albers JW, Andersen H, et al; Toronto Expert Panel on Diabetic Neuropathy. Diabetic polyneuropathies: update on research definition, diagnostic criteria and estimation of severity. Diabetes Metab Res Rev. 2011 Oct;27(7):620-8. https://onlinelibrary.wiley.com/doi/full/10.1002/dmrr.1226 http://www.ncbi.nlm.nih.gov/pubmed/21695763?tool=bestpractice.com

Possible clinical DSPN

• Presence of symptoms or signs of DSPN.

• Symptoms may include:

  • Decreased sensation.

  • Positive neuropathic sensory symptoms (e.g., "asleep numbness," "prickling" or "stabbing," "burning" or "aching" pain) predominantly in the toes, feet or legs.

• Signs may include:

  • Symmetric decrease of distal sensation

  • Unequivocally decreased or absent ankle reflexes.

Probable clinical DSPN

• A combination of symptoms and signs of distal sensorimotor polyneuropathy with any two or more of the following:

  • Neuropathic symptoms

  • Decreased distal sensation

  • Unequivocally decreased or absent ankle reflexes.

Confirmed clinical DSPN

• An abnormal nerve conduction study, and a symptom or symptoms or a sign or signs of sensorimotor polyneuropathy.

Subclinical DSPN (stage 1a)

• No signs or symptoms of polyneuropathy

• Abnormal nerve conduction.

Toronto Expert Panel on Diabetic Neuropathy definition of small-fiber neuropathy[3]Dyck PJ, Albers JW, Andersen H, et al; Toronto Expert Panel on Diabetic Neuropathy. Diabetic polyneuropathies: update on research definition, diagnostic criteria and estimation of severity. Diabetes Metab Res Rev. 2011 Oct;27(7):620-8. https://onlinelibrary.wiley.com/doi/full/10.1002/dmrr.1226 http://www.ncbi.nlm.nih.gov/pubmed/21695763?tool=bestpractice.com

Possible small-fiber neuropathy

• Presence of distal symmetric symptoms, and/or clinical signs of small-fiber damage.

Probable small-fiber neuropathy

• Presence of distal symmetric symptoms, clinical signs of small-fiber damage, and normal or abnormal sural nerve conduction (NC) study.

Definite small-fiber neuropathy

• Presence of length-dependent symptoms, clinical signs of small-fiber damage, normal or abnormal sural NC study, and/or abnormal quantitative sensory testing (QST) thermal thresholds at the foot and reduced intraepidermal nerve fiber density (IENFD) at the ankle.

Skin biopsy is used for determining IENFD.[3]Dyck PJ, Albers JW, Andersen H, et al; Toronto Expert Panel on Diabetic Neuropathy. Diabetic polyneuropathies: update on research definition, diagnostic criteria and estimation of severity. Diabetes Metab Res Rev. 2011 Oct;27(7):620-8. https://onlinelibrary.wiley.com/doi/full/10.1002/dmrr.1226 http://www.ncbi.nlm.nih.gov/pubmed/21695763?tool=bestpractice.com [82]Lauria G, Hsieh ST, Johansson O, et al; European Federation of Neurological Societies; Peripheral Nerve Society. European Federation of Neurological Societies/Peripheral Nerve Society Guideline on the use of skin biopsy in the diagnosis of small fiber neuropathy. Report of a joint task force of the European Federation of Neurological Societies and the Peripheral Nerve Society. Eur J Neurol. 2010 Jul;17(7):903-12, e44-9. https://onlinelibrary.wiley.com/doi/full/10.1111/j.1468-1331.2010.03023.x http://www.ncbi.nlm.nih.gov/pubmed/20642627?tool=bestpractice.com Nerve biopsy, due to its invasive and highly specialized nature, is not recommended for routine use. Corneal nerve fiber density assessed using corneal confocal microscopy has demonstrated sensitivity and specificity equivalent to IENFD for the diagnosis of diabetic peripheral neuropathy.[83]Chen X, Graham J, Dabbah MA, et al. Small nerve fiber quantification in the diagnosis of diabetic sensorimotor polyneuropathy: comparing corneal confocal microscopy with intraepidermal nerve fiber density. Diabetes Care. 2015 Jun;38(6):1138-44. https://diabetesjournals.org/care/article/38/6/1138/37389/Small-Nerve-Fiber-Quantification-in-the-Diagnosis http://www.ncbi.nlm.nih.gov/pubmed/25795415?tool=bestpractice.com [114]Ziegler D, Papanas N, Zhivov A, et al; German Diabetes Study (GDS) Group. Early detection of nerve fiber loss by corneal confocal microscopy and skin biopsy in recently diagnosed type 2 diabetes. Diabetes. 2014 Jul;63(7):2454-63. https://diabetesjournals.org/diabetes/article/63/7/2454/34349/Early-Detection-of-Nerve-Fiber-Loss-by-Corneal http://www.ncbi.nlm.nih.gov/pubmed/24574045?tool=bestpractice.com

Toronto Expert Panel on Diabetic Neuropathy staging of cardiac autonomic neuropathy (CAN)[23]Spallone V, Ziegler D, Freeman R, et al; Toronto Consensus Panel on Diabetic Neuropathy. Cardiovascular autonomic neuropathy in diabetes: clinical impact, assessment, diagnosis, and management. Diabetes Metab Res Rev. 2011 Oct;27(7):639-53. https://onlinelibrary.wiley.com/doi/full/10.1002/dmrr.1239 http://www.ncbi.nlm.nih.gov/pubmed/21695768?tool=bestpractice.com

Stage 1: Possible or early CAN: presence of one abnormal cardiovascular reflex test, to be confirmed over time

Stage 2: Definite or confirmed CAN: at least two abnormal cardiovascular reflex tests are required

Stage 3: Severe or advanced CAN: presence of definite CAN plus the presence of orthostatic hypotension