What is Peripheral Neuropathy?
 

• Peripheral Neuropathy: Functional impairment or pathological damage of the peripheral nervous system (motor, sensory, or autonomic nerves), typically presenting in a symmetrical "stocking-glove" distribution for length-dependent neuropathies, or as focal/multifocal deficits.

• Clinical Symptom Categories:

  • Sensory Symptoms: Numbness, paresthesias (tingling, "pins and needles"), dysesthesia, hyperalgesia, and neuropathic pain (burning, shooting, or electrical sensations).

  • Motor Symptoms: Muscle weakness, cramping, fasciculations, distal muscle wasting, and loss of reflexes.

  • Autonomic Symptoms: Orthostatic hypotension, abnormal sweating, gastrointestinal dysmotility, urinary retention, and erectile dysfunction.

Primary Causes of Peripheral Neuropathy
 

• Inherited Neuropathies: Charcot-Marie-Tooth (CMT) disease and others

• Immune-Mediated & Inflammatory Neuropathies: Guillain-Barré syndrome (acute inflammatory demyelinating polyneuropathy) and multifocal motor neuropathy.

• Compression & Entrapment Neuropathies: Carpal tunnel syndrome, ulnar neuropathy, tarsal tunnel syndrome, and radiculopathies (spine).

• Traumatic & Physical Nerve Injury: Lacerations, compression injuries, chronic repetitive trauma, and ischemia.

Secondary Causes of Peripheral Neuropathy
 

• Metabolic & Endocrine Disorders: Diabetes mellitus (diabetic peripheral neuropathy), impaired glucose tolerance, uremia from chronic kidney disease, and hepatic failure.

• Nutritional Deficiencies & Toxicities: Vitamin B12 deficiency, thiamine (B1) deficiency, chronic heavy metal exposure (lead, arsenic, mercury), and organophosphate toxicity.

• Infectious & Post-Infectious States: HIV-associated neuropathy, Lyme disease, leprosy, shingles (post-herpetic neuralgia), and neurosyphilis.

• Malignancy & Paraneoplastic Syndromes: multiple myeloma, monoclonal gammopathy of undetermined significance (MGUS), and amyloidosis.

• Medication-Induced & Iatrogenic: Chemotherapy agents (vincristine, platinum-based drugs, taxanes), certain anti-infectives (isoniazid, nitrofurantoin), and chronic excessive pyridoxine (Vitamin B6) supplementation.

• Vascular & Connective Tissue Disorders: Vasculitic neuropathies associated with systemic autoimmune diseases (e.g., lupus, rheumatoid arthritis, Sjögren's syndrome).

Diagnostics
 

• Clinical History & Physical Examination: Onset and progression, distribution of symptoms, sensory modality testing (monofilament, vibration tuning fork, pinprick), and deep tendon reflex assessment.

• Laboratory Testing:

• Comprehensive metabolic panel (fasting blood glucose, HbA1c, renal and hepatic function panels).

• Vitamin B12

• Thyroid-stimulating hormone (TSH).

• Serum protein electrophoresis (SPEP) with immunofixation and free light chains (to screen for MGUS/myeloma).

• Autoimmune and vasculitic serologies (ANA, ANCA, anti-SSA/SSB) when clinically indicated.

• Electrodiagnostic Studies: Electromyography (EMG) and nerve conduction studies (NCS) to characterize the neuropathy as axonal versus demyelinating, and generalized versus focal.

• Invasive & Specialized Testing: Skin biopsy (to assess epidermal nerve fiber density for small-fiber neuropathy) or nerve/muscle biopsy in select inflammatory or vasculitic cases.

Management 
 

Non-Pharmacological Management

• Physical & Occupational Therapy: Balance training, gait stabilization, strengthening exercises, and fine-motor coordination training.

• Foot Care & Injury Prevention: Rigorous daily foot inspections, proper footwear, and protective management to prevent ulcerations or infections (especially in diabetic neuropathy).

• Assistive Devices & Modalities: Orthotics, canes, or walkers for stability; transcutaneous electrical nerve stimulation (TENS) for pain control.

Pharmacological Management

• Neuropathic Pain Medications:

  • Calcium channel alpha-2-delta ligands (gabapentin, pregabalin).

  • Serotonin-norepinephrine reuptake inhibitors (duloxetine, venlafaxine).

  • Tricyclic antidepressants (amitriptyline, nortriptyline) 

  • Topical agents (capsaicin cream, lidocaine patches) 

• Targeted Disease-Modifying Therapy:

  • Strict glycemic control for diabetic neuropathy.

  • Immunomodulatory therapies, corticosteroids, IVIG, or plasma exchange for immune-mediated neuropathies (e.g., CIDP, Guillain-Barré).

  • Vitamin supplementation for nutritional deficiencies.

• Medication Reconciliation: Discontinuing or substituting causative neurotoxic agents (e.g., specific chemotherapy agents or medications associated with neuropathy).