Diagnosing and Managing Neuropathy

Introduction to Neuropathy Diagnosis

The American Diabetes Association recommends diagnosing neuropathy through a systematic clinical assessment combining detailed history, focused neurologic examination testing both small and large fiber function, followed by nerve conduction studies/electromyography to confirm the diagnosis and distinguish axonal from demyelinating patterns, while simultaneously excluding treatable secondary causes through targeted laboratory testing 1

The American Diabetes Association suggests that chronic progressive neuropathy (months to years) suggests diabetic neuropathy, hereditary conditions, or chronic inflammatory processes 1
The American Diabetes Association recommends identifying which fiber types are affected, including small fiber symptoms such as burning pain, tingling, dysesthesias, and temperature sensitivity, and large fiber symptoms such as numbness, loss of balance, and loss of protective sensation 1
Autonomic symptoms such as orthostatic dizziness, syncope, dry cracked skin in extremities, erectile dysfunction, bladder dysfunction, and gastrointestinal symptoms should be assessed 1, 2

A comprehensive sensory and reflex examination assessing both small and large fiber function should be performed, including pinprick sensation, temperature sensation, vibration perception, and pressure sensation 3, 1
Ankle reflexes should be assessed for diminished or absent responses 3, 4

Nerve conduction studies and electromyography should be obtained as the primary diagnostic tool for large-fiber neuropathy, and to distinguish between axonal and demyelinating patterns 6
Laboratory tests such as fasting blood glucose, HbA1c, vitamin B12 level, and thyroid-stimulating hormone should be ordered to exclude other causes of neuropathy 7

For patients with diabetes, a structured approach should be followed, including timing of screening, annual screening thereafter, and clinical diagnosis of distal symmetric polyneuropathy 8, 3, 4
Autonomic function testing, including heart rate variability with deep breathing, postural hypotension testing, and ambulatory blood pressure monitoring, should be performed if autonomic neuropathy is suspected 1, 2, 8

Diabetic neuropathy is a diagnosis of exclusion, and other causes such as chronic inflammatory demyelinating polyneuropathy should be ruled out 1, 6
Asymptomatic neuropathy should not be missed, and annual screening with 10-g monofilament is mandatory even in asymptomatic patients 1
Conventional electrophysiology may miss early small fiber-predominant disease, and skin biopsy should be considered if symptoms suggest small fiber involvement but NCS is normal 7
Medication-induced neuropathy should not be forgotten, and common culprits such as chemotherapy agents, antimicrobials, and anti-TNF agents should be considered 7