From the Guidelines
Diagnosis of peripheral neuropathy requires a comprehensive clinical evaluation, including a careful clinical history and a peripheral neurological and vascular examination of the lower extremities to exclude other causes of neuropathic pain and leg/foot pain. The diagnostic criteria for peripheral neuropathy involve a combination of clinical assessment, laboratory testing, and specialized tests.
Key Components of Diagnosis
- A detailed clinical history focusing on symptom onset, progression, distribution, and associated conditions like diabetes, alcohol use, vitamin deficiencies, or medication exposure 1
- A peripheral neurological and vascular examination of the lower extremities to exclude other causes of neuropathic pain and leg/foot pain, such as peripheral vascular disease, arthritis, malignancy, alcohol abuse, and spinal canal stenosis 1
- Laboratory testing, including complete blood count, comprehensive metabolic panel, HbA1c, vitamin B12, folate, thyroid function tests, and serum protein electrophoresis to identify common causes
- Nerve conduction studies and electromyography to characterize the neuropathy as axonal or demyelinating and to determine if it's sensory, motor, or mixed
- Skin biopsy for epidermal nerve fiber density to help diagnose small fiber neuropathy when conventional tests are normal
- Additional specialized testing, such as genetic testing for hereditary neuropathies, cerebrospinal fluid analysis for inflammatory neuropathies, or nerve biopsy in select cases
Assessment of Painful Symptoms
- Simple numeric rating scales, such as an 11-point Likert scale, can be used to assess the frequency and severity of painful symptoms 1
- Validated scales and questionnaires, including the neuropathic pain symptom inventory, the modified brief pain inventory, the neuropathic pain questionnaire, the LANNS pain scale, and the McGill Pain Questionnaire, can be used to assess painful symptoms 1
- Quality of life (QoL) can be assessed using generic instruments or validated, neuropathy-specific QoL instruments, such as NeuroQol, Norfolk Quality of Life Scale, and Neuropathic Pain Impact on Quality-of-Life questionnaire (NePIQoL) 1
Importance of Accurate Diagnosis
Accurate diagnosis of peripheral neuropathy is crucial for appropriate management, as treating the cause can prevent further nerve damage and potentially allow for recovery of nerve function. A systematic approach to diagnosis, including clinical evaluation, laboratory testing, and specialized tests, is essential to identify the underlying etiology and develop an effective treatment plan.
From the Research
Diagnostic Criteria for Peripheral Neuropathy
The diagnostic criteria for peripheral neuropathy involve a comprehensive approach that includes:
- Clinical assessment and history taking to identify the underlying etiology and exclude potentially treatable causes 2, 3, 4
- Physical examination, including a comprehensive neurologic and musculoskeletal evaluation 3
- Judicious laboratory testing, such as:
- Electrodiagnostic studies, including nerve conduction studies and electromyography, to help differentiate between axonal and demyelinating neuropathy 2, 3, 4
- Nerve biopsy, if the diagnosis remains unclear 2
- Lumbar puncture and cerebrospinal fluid analysis, if clinically indicated, such as in the diagnosis of Guillain-Barré syndrome and chronic inflammatory demyelinating neuropathy 2
Clinical Phenotypes of Peripheral Neuropathy
Peripheral neuropathy can be classified into different clinical phenotypes, including:
- Sensory alterations, such as sensory loss, numbness, pain, or burning sensations in a "stocking and glove" distribution of the extremities 3
- Proximal numbness, distal weakness, or atrophy 3
- Axonal versus demyelinating or mixed neuropathy, as determined by electrodiagnostic studies 2, 3, 4
Diagnostic Approach
A systematic approach to the diagnosis of peripheral neuropathy involves: