What is the recommended approach for a peripheral neuropathy screen?

Peripheral Neuropathy Screening

Screen all patients with type 2 diabetes at diagnosis and type 1 diabetes patients 5 years after diagnosis, then annually thereafter, using a 10-g monofilament test combined with at least one additional neurological assessment tool. 1

Screening Timing and Frequency

• Type 2 diabetes: Begin screening at diagnosis 1
• Type 1 diabetes: Begin screening 5 years after diagnosis 1
• Frequency: Repeat at least annually for all diabetic patients 1
• Higher-risk patients: Screen more frequently (every 1-6 months depending on risk category) 1

Required Clinical Tests

The screening examination must include:

Small Fiber Function Assessment (Choose One)

• Pinprick sensation testing 1
• Temperature perception testing 1

Large Fiber Function Assessment (Both Required)

• Vibration perception using a 128-Hz tuning fork 1
• 10-g monofilament testing at multiple foot sites 1

Additional Assessments

• Ankle reflexes 1
• Pressure sensation 1

Diagnostic Criteria

Loss of protective sensation (LOPS) is confirmed when:

• Absent 10-g monofilament sensation AND one other abnormal neurological test 1
• This combination identifies feet at highest risk for ulceration and amputation 1

Complete Screening Protocol

Beyond sensory testing, the comprehensive foot examination should include:

• Detailed history: Document diabetes control, smoking, exercise tolerance, claudication, rest pain, prior ulcerations or amputations 1
• Skin integrity assessment: Look for breaks, calluses, or deformities 1
• Vascular examination: Palpate dorsalis pedis and posterior tibial pulses 1
• Structural assessment: Identify bunions, hammertoes, prominent metatarsals that increase ulceration risk 1

When Advanced Testing Is NOT Needed

Electrophysiological testing (EMG/nerve conduction studies) is rarely indicated except when: 1

• Clinical features are atypical
• Diagnosis remains unclear after clinical examination
• Asymmetric pattern of symptoms suggests alternative diagnosis 1

Exclusion of Alternative Causes

Before confirming diabetic neuropathy, rule out: 1

• Cervical/lumbar radiculopathy or spinal stenosis 1
• Vitamin B12 deficiency 1, 2
• Hypothyroidism 1, 3, 2
• Alcohol toxicity 1, 3
• Neurotoxic medications (especially chemotherapy) 1
• Renal insufficiency causing metabolic toxicity 1
• Chronic inflammatory demyelinating neuropathy 1
• HIV infection 1

Autonomic Neuropathy Screening

Assess for autonomic symptoms in patients with microvascular complications: 1

• Hypoglycemia unawareness 1
• Resting tachycardia or orthostatic hypotension 1
• Gastroparesis, constipation, diarrhea, fecal incontinence 1
• Erectile dysfunction 1
• Neurogenic bladder 1
• Abnormal sweating patterns 1

Common Pitfalls to Avoid

• Do not rely solely on symptoms: Up to 50% of diabetic peripheral neuropathy is asymptomatic 1
• Do not skip the 10-g monofilament test: This is the single most sensitive test for identifying ulceration risk 1
• Do not perform only one test: The combination of monofilament with another modality is required for diagnosis 1
• Do not assume diabetes is the cause: Always consider and exclude other treatable etiologies 1, 3, 2