Assessment and Management of Diabetic Peripheral Neuropathy

Initial Clinical Assessment

The American Diabetes Association recommends that all patients with type 2 diabetes should be screened for peripheral neuropathy at diagnosis, and type 1 diabetes patients should be screened 5 years after diagnosis, then annually thereafter using a structured clinical examination that includes 10-g monofilament testing plus at least one additional neurological test 1, 2
Patients should be assessed for specific symptoms: numbness, tingling, burning sensations, or pain in a distal symmetric "stocking and glove" distribution, with documentation of these symptoms 3, 4
Pain severity should be assessed using a simple numeric rating scale (0-10 Likert scale) 5, 4
Nocturnal exacerbation of symptoms is characteristic of diabetic neuropathy and should be noted 5
Autonomic symptoms such as orthostatic dizziness, syncope, constipation, diarrhea, urinary retention, erectile dysfunction, and abnormal sweating should be screened for 1, 2
Risk factors including diabetes duration, glycemic control, smoking, alcohol use, chemotherapy exposure, and family history should be identified 6, 1

The examination must assess both small-fiber and large-fiber function using multiple modalities, including pinprick sensation testing, temperature perception, vibration perception using a 128-Hz tuning fork, and lower-extremity reflexes (ankle reflexes) 3, 1
Protective sensation should be assessed with 10-g monofilament testing at multiple sites on each foot, as this is the single most sensitive test for identifying ulceration risk 2, 6
Loss of protective sensation (LOPS) is confirmed when 10-g monofilament sensation is absent plus one other abnormal neurological test 2

Initial testing panel should include fasting blood glucose and hemoglobin A1c, complete blood count, vitamin B12 level, thyroid-stimulating hormone (TSH) and free T4, and should be ordered for all patients with suspected peripheral neuropathy 4, 6
Additional testing such as hepatitis B, C, and HIV testing, anti-ganglioside antibodies, and anti-MAG antibodies should be considered when clinically indicated 4, 6

Nerve conduction studies and electromyography are rarely needed for typical diabetic neuropathy but should be ordered when clinical features are atypical, the diagnosis is unclear, or asymmetric symptoms are present 3
These studies help differentiate axonal versus demyelinating neuropathy, entrapment syndromes from generalized neuropathy, and severity and distribution of nerve involvement 5

Glycemic optimization is the foundational disease-modifying intervention and should be targeted to individualized HbA1c goals based on patient factors, as recommended by the American Diabetes Association 1, 4
Cardiovascular risk factor management, including optimizing blood pressure control, managing dyslipidemia aggressively, and addressing weight management, is crucial 3, 1, 4
First-line medications for neuropathic pain include duloxetine, pregabalin, gabapentin, and tricyclic antidepressants, but opioids should not be used due to potential adverse events 1, 4
Non-pharmacologic interventions such as regular physical activity, acupuncture, cognitive behavioral therapy, and concurrent treatment of sleep and mood disorders should be considered 4, 1

Up to 50% of diabetic peripheral neuropathy is asymptomatic, and diagnosis should not rely on symptoms alone 3, 2
Diabetic neuropathy is a diagnosis of exclusion, and other treatable causes should always be evaluated for 3, 5
Asymmetric symptoms should prompt evaluation for alternative etiologies, not diabetic neuropathy 5
Annual screening is mandatory even in asymptomatic patients to prevent ulceration and amputation, as recommended by the American Diabetes Association 1, 2
The 10-g monofilament test identifies feet at highest risk for ulceration and must be performed annually 3, 2