Peripheral Neuropathies in Older Adults

1. Peripheral Neuropathiesin Older Adults Annabel K. Wang, MD University of California, Irvine Department of Neurology

2. Peripheral Neuropathies • Common disorder • Prevalence of non-traumatic peripheral neuropathies • 2.4% in general population • 15% over the age of 40

3. Peripheral Neuropathies • Terms are confusing • polyneuropathy • neuropathy

4. Peripheral Neuropathies • Motor neuron disorders • Radiculopathies • Plexopathies • Single and Multiple Mononeuropathies • Symmetric Polyneuropathies • Motor Neuropathies • Sensory Ganglionopathies

5. Goals • Early Recognition • Early Treatment • Prevention of Complications

6. Objectives • Review symptoms and signs • Identify common causes • Discuss treatment options • Address co-morbidities

7. Symptoms • Positive or negative phenomena • Sensory symptoms early • Typically symmetric in onset • Weakness later • Distal symptoms predominant • Worse at night

8. Positive Phenomena • Tingling • Coldness • Burning • Electrical shocks • Stabbing sensations • Deep aching

9. Negative phenomena • Lack of sensation • Hypersensitivity

10. Associated Symptoms • Imbalance • Fatigue • Falls

11. Early Signs • Distal sensory loss: • Large Fibers • loss of vibration before proprioception • decreased ankle reflexes • Small fibers • Loss of pinprick and temperature • Stocking-glove distribution

12. Early Signs • Distal weakness • Toe extensors • Foot dorsiflexors • Finger extensors

13. Common Causes • Diabetes • Leprosy • Vitamin B12 deficiency

14. Diabetes • Prevalence of Diabetes (2011): 8.3% of population • 25.8 million children and adults in the US • Age 65 years or older • 10.9 million, or 26.9% of this age group have diabetes

15. Diabetes • 60-70% will develop neuropathy • polyneuropathy, autonomic neuropathy, CTS • Association with amputation • major contributor of amputations • 60% of non-traumatic amputations • 65,700 amputations from 2006

16. Diabetic Polyneuropathy • Defined as the presence of symptoms and/or signs of peripheral nerve dysfunction in people with diabetes after the exclusion of other causes • An absence of symptoms should never be assumed to indicate an absence of signs

17. Diabetic Polyneuropathy • Treatment • Glucose control • Pain management • Management of autonomic symptoms

18. Leprosy • Rare in United States • Endemic areas • Often sensory (ulnar and peroneal nerves) • Associated skin lesions • Hypertrophic nerves • Nerve biopsy • Treat underlying infection

19. Vitamin B12 Deficiency • Prevalence: 5-20% • Malabsorption, insufficient intake, pernicious anemia, gastric bypass surgery, medications • Distal sensory and motor loss • Combined subacute degeneration • Vitamin B12 (<260 pmol/L) and methylmalonic acid (271 nmol/L) levels • Supplementation: intramuscular or oral

20. Approach • Acute vs. chronic onset • Acute fulminant and live threatening • Axonal vs. demyelinating • Demyelinating forms respond well to immunotherapy

21. Acute Polyneuropathies • Guillain-Barre Syndrome or Acute Inflammatory Demyelinating Polyradiculoneuropathy • Porphyria • Toxic (arsenic and thallium)

22. Chronic Polyneuropathies • Inherited (CMT, HMSN, HNPP) • Family History • Foot Deformities • Foot Ulcers • Acquired • “MINI”

23. Acquired Polyneuropathy “MINI” • Metabolic • Immune • Neoplastic • Infectious

24. Metabolic Causes • Diabetes • Uremia • Alcohol abuse • Hypothyroid • Vitamin B1 or B12 deficiency • Vitamin B6 toxicity • Medications/chemotherapy

25. Immune Causes • Vasculitis • Non-vasculitic • CIDP • MMN • Sarcoid • Sjogren’s

26. Neoplastic Causes • Paraneoplastic • Paraproteinemic

27. MGUS • Monoclonal gammopathy of unclear significance • Prevalence: • 3% of persons >50 years • 5% >70 years • 1% per year risk of progression to multiple myeloma (MM) or a related disorder

28. Infectious Causes • Leprosy • Hepatitis C • Lyme • HIV • West Nile • Syphilis • Diptheria

29. Autonomic Symptoms • Lightheadedness or “dizziness” • Blurred vision • Dry eyes, dry mouth • Cold feet • Early satiety, constipation, diarrhea • Urinary retention, incontinence • Erectile Dysfunction • Hypohidrosis

30. Dysautonomias • Diabetes • Amyloidosis (acquired and inherited) • Paraneoplastic • Inherited (HSAN) • Sjogren’s Neuropathy • Porphyria

31. Differential Diagnosis • Small fiber neuropathy • Plantar fasciitis • Osteoarthritis • Vascular insufficiency • Cervical myelopathy • Lumbosacral radiculopathy

32. Neurophysiology • Electromyography • Autonomic Testing • Quantitative Sensory Studies

33. Electromyography (EMG) • Two part test: • Nerve conduction studies • Needle electromyography • Establish diagnosis of polyneuropathy • Distinguish demyelinating from axonal • Differentiate radiculopathy, plexopathy • Normal in small fiber and autonomic neuropathy

34. Autonomic Testing • Heart rate response to deep breathing • Valsalva Maneuver • Tilt Table • Quantitative Sudomotor Axon Reflex Test

35. Basic Laboratory Investigation • Hematology: • complete blood count • erythrocyte sedimentation rate • C-reactive protein • vitamin B12, folate, • Methylmalonic acid, homocysteine

36. Basic Laboratory Investigation • Biochemical and endocrine: • comprehensive metabolic panel (fasting glucose) • thyroid function tests • serum immunofixation. • glucose tolerance test if indicated

37. Basic Laboratory Investigation • Urine: • urinalysis • urine immunofixation. • Drugs and toxins

38. Specialized Laboratory Investigation • Malignancies: • skeletal radiographic survey • mammography • computed tomography or magnetic resonance imaging of chest, abdomen, and pelvis • ultrasound of abdomen and pelvis • positron emission tomography • cerebrospinal fluid analysis including cytology • serum paraneoplastic antibody profile

39. Specialized Laboratory Investigation • Connective tissue diseases and vasculitis: • antinuclear antigen profile • rheumatoid factor • anti-Ro/SSA, anti-La/SSB, • antineutrophil cytoplasmic antigen antibody (ANCA) profile • cryoglobulins.

40. Specialized Laboratory Investigation • Infectious agents: • Campylobacter jejuni • Cytomegalovirus • hepatitis panel (B and C) • HIV • Lyme disease • herpes viruses • West Nile virus • cerebrospinal fluid analysis.

41. Biopsy • Nerve biopsy • Sural • Superficial peroneal • Epidermal skin biopsy

42. Nerve Biopsy • Vasculitis • Lymphoma • Amyloid • Sarcoid • Leprosy • Inflammation

43. Management • Care of feet • Inspect feet daily (mirror) • Keep feet clean and moisturized • Foot care with podiatrist • Molded shoes • Avoid walking barefoot • Checking temperatures of water/sand

44. Treatment • Foot care • Physical Therapy • Gait and balance exercises • Ankle supports (orthotics) • Occupational Therapy (ADLs)

45. Therapeutic Treatment • Importance of diagnosis • Recognition of the underlying cause • Glucose control • Thyroid medication • Vitamin supplementation or reduction • Antibiotics or antiviral medications • Immunotherapy

46. Symptomatic Treatment • Only 2 medications are FDA approved for diabetic polyneuropathy • Duloxetine • pregabalin

47. Symptomatic Treatment • Pain management limited by side effects • Analgesics • Anti-inflammatories • Antiepileptics • Antidepressants • Narcotics

48. Co-morbidities • Depression • Decreased mobility • Falls • Fear of falls • Social isolation • Osteoporosis

49. Complications • Risk of injury due to lack of sensation • Charcot joints • Foot ulcers • Amputations • Falls

50. Summary • Common disorder • >40 years of age: 15% • Routine screening for diabetes, vitamin B12 deficiency, serum immunofixation.