Table 3.

(adapted from Wolfe, 1999)²

Diagnostic Criteria for CSPN*
Inclusion Criteria
Symptoms
	Loss of sensation (numbness) or altered sensation (tingling/paresthesia/dysesthesia or pain beginning in the distal extremities(usually with onset in feet before hands) Symptoms present for at least 3 months No symptoms of weakness Symptoms of gait unsteadiness and autonomic dysfunction are allowable
Signs
	Sensory signs are present in a symmetrical fashion in distal limbs and may include any of the following: loss of vibration, proprioception, light touch, pain(pinprick),or temperature Hyporeflexia or areflexia may be present but is not required, even at the ankles Minimal weakness or atrophy is allowable in muscles supplying movement to the fingers and toes
Laboratory Studies
	Electrophysiology: sensory and motor NCS and needle EMG are often, but not invariably, abnormal; when abnormal, findings indicate a primarily axonal PN Quantitative sensory tests: vibration and temperature thresholds are often, but not invariably abnormal Other studies: if NCS/EMG and QST are normal, other studies including skin punch biopsy to measure epidermal nerve fiber density and autonomic studies including sudomotor tests (quantitative sudomotor axon reflex test, Silastic imprint testing, sympathetic skin response) and vasomotor test (heart rate variability to deep breathing, Valslva ratio) may provide evidence of peripheral nerve dysfunction Blood and urine tests: these should be normal or negative; a monoclonal protein by serum protein electrophoresis and/or immunofixation electrophoresis is allowable in patients with MGUS
Exclusion criteria
Any identifiable metabolic, toxic, infectious, systemic, or hereditary disorder known to cause PN NCS abnormalities consistent with demyelination If a monoclonal gammopathy is present, the presence of an underlying lymphoproliferative disorder, malignancy, or amyloidosis Weakness on examination other than mild toes and/or finger weakness

^*CSPN indicates cryptogenic sensory polyneuropathy; NCS, nerve conduction studies; EMG, electromyography; PN; polyneuropathy, QST, quantitative sensory testing; and MGUS, monoclonal gammopathy of uncertain significance.