Basics
Description
Peripheral neuropathy is a general term for peripheral nerve disorders that may affect motor, sensory, or vasomotor nerve fibers and presents with marked muscle weakness, atrophy pain and numbness ‚
Etiology
Variable, depending on presentation of symptoms; refer to Differential Diagnosis ‚
Diagnosis
Signs and Symptoms
- Sensory nerve dysfunction:
- Numbness
- Localized tingling
- Paresthesias
- Dysesthesias
- Vibration and position sensations are decreased with large-fiber neuropathy
- Pain and temperature sensation are decreased with small-fiber neuropathy
- Deep tendon reflexes are decreased secondary to decreased sensation of afferent limb
- Motor nerve dysfunction:
- Weakness:
- Distal > proximal
- Occasionally fasciculations
- Muscle atrophy, diminished tone with long-standing motor nerve involvement
- Loss of reflexes secondary to slowing of conduction along motor nerve efferent limb
- Autonomic nerve dysfunction:
- Orthostasis
- Constipation
- Urinary retention
- Impotence
History
- Duration of symptoms
- Symmetric or asymmetric symptoms
- Distal or proximal symptoms
- Motor, sensory, or mixed
Physical Exam
- Thorough head-to-toe physical exam
- Focus on neurologic exam:
- Motor weakness
- Sensory loss typically in stocking-glove distribution
Absence of reflexes early in course could represent demyelinating neuropathy such as Guillain " “Barre syndrome (acute inflammatory demyelinating syndrome [AIDP]). ‚
Essential Workup
- Studies based on acuteness, severity of neuropathy, and most likely diagnosis
- Neurologic consult early if acute and severe symptoms
Diagnosis Tests & Interpretation
Lab
- Basic metabolic panel
- CBC
- Liver function tests
- Urinalysis
- Thyrotropin-stimulating hormone
- HIV or vitamin B12 based on individual presentations
- Electrocardiogram
Imaging
- CXR if indicated
- Head CT if indicated
Diagnostic Procedures/Surgery
- Electromyographic studies, nerve conduction studies, and nerve biopsy per neurologic consult on admission or outpatient follow-up
- Lumbar puncture as appropriate for AIDP
Differential Diagnosis
- Focal:
- Entrapment
- Common sites of compression:
- Carpal, ulnar tunnel
- Tarsal tunnel
- Peroneal
- Myxedema
- Rheumatoid arthritis
- Amyloidosis
- Acromegaly
- Trauma
- Ischemic lesions
- Diabetes mellitus (DM)
- Vasculitis
- Leprosy
- Sarcoidosis
- Neoplastic infiltration or compression
- Multifocal (mononeuropathy multiplex):
- DM
- Vasculitis:
- Polyarteritis nodosa
- Systemic lupus erythematosus
- Sj ƒ ¶gren syndrome
- Sarcoidosis
- Leprosy
- Malignancy related
- HIV/AIDS
- Hereditary predisposition to pressure palsies
- Symmetric:
- Endocrine:
- Most common is DM
- Hypothyroidism
- Medications:
- Isoniazid
- Lithium
- Metronidazole
- Phenytoin
- Cimetidine
- Hydralazine
- Amitriptyline
- Amiodarone
- Nutritional diseases:
- Alcoholism
- B12/folate deficiency
- Thiamine
- Critical illness neuropathy
- Hypophosphatemia
- Guillain " “Barre syndrome (AIDP)
- Toxic neuropathy:
- Carbon monoxide
- Acrylamide
- Carbon disulfide
- Ethylene oxide
- Organophosphate esters
- Lead
- Myelopathy mimicking peripheral neuropathy
- Back pain
- Saddle anesthesia
- Lower extremity weakness
Treatment
Pre-Hospital
- Pain control as needed
- Airway protection as indicated
Initial Stabilization/Therapy
Establish airway protection with severe acute peripheral neuropathy, such as Guillain " “Barre syndrome ‚
Ed Treatment/Procedures
- Variable depending on acuity of symptoms
- Discontinuation offending toxin or agent
- Treatment underlying systemic disease
Medication
- Variable depending on underlying diagnosis
- Opioid analgesics
- Gabapentin 300 mg PO daily then BID on day 2, then TID on day 3 up to 1,800 mg/d div. TID
- Carbamazepine 100 mg PO BID for trigeminal neuralgia
- IV immunoglobulin for Guillain " “Barre syndrome (AIDP)
Follow-Up
Disposition
Admission Criteria
- Respiratory distress or acute gait disturbance
- Intractable pain
Discharge Criteria
Stable respiratory and gait status with outpatient follow-up ‚
Issues for Referral
Neurology " ”based on duration, severity of presentation ‚
Followup Recommendations
Primary care or neurology depending on etiology and severity of symptoms ‚
Pearls and Pitfalls
Failure to diagnose Guillain " “Barre syndrome (AIDP) ‚
Additional Reading
- Azhary ‚ H, Farooq ‚ MU, Bhanushali ‚ M, et al. Peripheral neuropathy: Differential diagnosis and management. Am Fam Physician. 2010;81:887 " “892.
- Gilron ‚ I, Watson ‚ CP, Cahill ‚ CM, et al. Neuropathic pain: A practical guide for the clinician. CMAJ. 2006;175:265 " “275.
- Marx ‚ JA, Hockberger ‚ RS, Walls ‚ RM, et al. Rosens Emergency Medicine: Concepts and Clinical Practice. 7th ed. St. Louis, MO: Mosby; 2009.
- Pascuzzi ‚ RM. Peripheral neuropathy. Med Clin North Am. 2009;93:317 " “342.
Codes
ICD9
- 356.9 Unspecified hereditary and idiopathic peripheral neuropathy
- 782.0 Disturbance of skin sensation
ICD10
- G62.9 Polyneuropathy, unspecified
- R20.0 Anesthesia of skin
- R20.2 Paresthesia of skin
SNOMED
- 302226006 peripheral nerve disease (disorder)
- 44077006 Numbness (finding)
- 91019004 Paresthesia (finding)
- 62507009 Pins and needles (finding)