1. Overview & Pathophysiology
Diabetic neuropathy is a heterogeneous group of disorders affecting the somatic and autonomic nervous systems. It is the most common complication of diabetes.
Distal Symmetric Polyneuropathy (DSPN): The most common form, typically presenting as a “stocking-glove” sensory loss or pain. It is a major risk factor for foot ulcers and amputation.
Risk Factors: The development of neuropathy is multifactorial. Key risk factors include:
Elevated blood glucose (A1C).
Elevated triglycerides.
High Body Mass Index (BMI).
Smoking.
Hypertension.
2. Screening Protocols
Screening is vital because the early stages of neuropathy are often asymptomatic (loss of sensation).
Frequency:
Type 1 Diabetes: Start 5 years post-diagnosis, then annually.
Type 2 Diabetes: Start at diagnosis, then annually.
Method (The “10g Monofilament”):
Screening should include testing with a 10g Semmes-Weinstein monofilament to detect Loss of Protective Sensation (LOPS).
Other assessments:
Vibration (128 Hz tuning fork).
Temperature.
Pinprick sensation.
Proprioception.
3. Management Strategies
Management is divided into prevention/slowing progression and symptom management.
A. Disease Modification (Glycemic Control)
Type 1 Diabetes: Intensive glycemic control significantly prevents or delays the development of neuropathy.
Type 2 Diabetes: Intensive control reduces the frequency of neuropathy but is less effective than in Type 1.
B. Management of Painful Neuropathy Neuropathic pain can be severe and debilitating (burning, shooting, lancinating). Treatment aims to reduce pain by ~30–50% and improve quality of life/sleep.
First-Line Pharmacotherapy:
Anticonvulsants: Pregabalin, Gabapentin.
Antidepressants (SNRI): Duloxetine, Venlafaxine.
Antidepressants (TCA): Amitriptyline, Nortriptyline (use with caution due to anticholinergic side effects).
Second-Line:
Opioid-like agents (e.g., Tramadol, Tapentadol) may be considered but have higher risk profiles.
5. Diabetes Canada 2018 Clinical Practice Guidelines Recommendations
Key takeaways from the “Recommendations” section (Page S220).
Screening:
Type 1: Screen annually starting 5 years post-diagnosis [Grade D, Consensus].
Type 2: Screen annually starting at diagnosis [Grade D, Consensus].
Tools: Use the 10g monofilament testing of the dorsal aspect of the great toe.
Glycemic Control: Optimize control to prevent/delay neuropathy in Type 1 [Grade A, Level 1] and Type 2 [Grade B, Level 2].
Pain Management:
Examples of agents: Pregabalin, Duloxetine, Gabapentin, Amitriptyline, Venlafaxine [Grade B, Level 2 for most].
Opioids (Tapentadol, Tramadol) are second-line [Grade B].