Sensory

921 views

Published on

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
921
On SlideShare
0
From Embeds
0
Number of Embeds
4
Actions
Shares
0
Downloads
38
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Sensory

  1. 1. Sensory & Peripheral Neuropathies Steve Sager, MPAS, PA-C
  2. 2. Learning Objectives • List common neuropathies • List the common toxins which produce neuropathies • Discuss the etiologies of common neuropathies • Differentiate between common neuropathies • Discuss the symptoms, signs, and treatments – Diabetic neuropathies – Alcoholic neuropathies – Uremic neuropathies – Autonomic neuropathies
  3. 3. Harrison’s on Neuropathies “The manifestations of such a disorder may be so bewildering and complex that it is difficult for a physician to know where to begin or how to proceed.”
  4. 4. General Information • More than 100 types of peripheral neuropathy have been identified • Each has its own characteristic set of symptoms, pattern of development, and prognosis • May involve sensory, motor, and/or autonomic nerves • A thorough patient history is critical
  5. 5. Common Neuropathies • Trigeminal neuralgia (tic douloureux) • Postherpetic neuralgia • Carpal Tunnel Syndrome • Sciatica • Guillain-Barré syndrome • Peroneal Muscular Atrophy • Diabetic Neuropathy Syndromes • Alcoholic Neuropathy • Uremic Neuropathy
  6. 6. Etiology of Neuropathies • Peripheral neuropathy may be – Inherited (C-M-T disease) – Acquired • Diabetes mellitus is a leading cause of peripheral neuropathy in the United States – ~60-70% of people with diabetes have mild to severe forms of nervous system damage. • Neuropathies with no apparent cause are termed idiopathic
  7. 7. Etiology of Neuropathies • Causes of acquired peripheral neuropathy include: – Physical injury (trauma) to a nerve – Tumors (neurofibromatoses) – Toxins • Heavy metals • Medications – Infections • Viral - HIV, EBV, HSV, CMV • Bacterial – Lyme disease
  8. 8. Etiology of Neuropathies • Causes of acquired peripheral neuropathy include: – Kidney disease – Autoimmune disease – Nutritional deficiencies • Vitamins E, B1, B6, B12, and niacin – Alcoholism • Thiamine deficiency – Vascular, metabolic, and endocrine disorders
  9. 9. Symptoms of Peripheral Neuropathies • Symptoms are related to the type of affected nerve and may be seen over a period of days, weeks, or years – Muscle weakness is the most common symptom of motor nerve damage – Sensory nerve damage causes a more complex range of symptoms because sensory nerves have a wider, more highly specialized range of functions
  10. 10. Symptoms of Peripheral Neuropathies • Sx’s of autonomic nerve damage are diverse and depend upon the affected organs/glands • Autonomic nerve dysfunction can become life threatening and may require emergency medical care in cases when breathing becomes impaired or when the heart begins beating irregularly – Common symptoms of autonomic nerve damage include: • unable to digest food easily • an inability to sweat normally, which may lead to heat intolerance • a loss of bladder control, which may cause infection or incontinence • an inability to control muscles that expand or contract blood vessels to maintain safe blood pressure levels • organ failure may occur.
  11. 11. Symptoms of Peripheral Neuropathies • Because every peripheral nerve has a highly specialized function in a specific part of the body, a wide array of symptoms can occur when nerves are damaged – Temporary numbness – Tingling/pricking sensations (paresthesia) – Sensitivity to touch – Burning pain (especially at night) – Muscle wasting – Paralysis – Organ or gland dysfunction
  12. 12. Symptoms of Peripheral Neuropathies Fiber Type Negative phenomena (loss of function) Positive phenomena (excessive firing) Motor Weakness, atrophy, hypotonia, fatigability, clumsiness, Twitching, cramps Sensory Paresthesia, ataxia, clumsiness “burning”, “tingling”, “pins-and-needles” dysesthesia Autonomic Orthostasis, anhidrosis, impotence, incontinence Hyperhidrosis
  13. 13. Radiculopathies • Cervical – due to stenosis or HNP – Sensory sx’s • Neck, shoulder, or scapular pain increases with movement – Motor sx’s • Loss of reflex based on nerve root involved • Lumbosacral – onset after heavy lifting – Sensory sx’s • Pain in lower back, hip or buttocks +/- radiation • Increases with prolonged sitting, coughing, sneezing or straining • HNP is generally unilateral • Spondylolysis/spondylolithesis typically presents with bilateral sx’s – Motor sx’s • Loss of reflex • Dx/Tx: X-rays, CT/MRI, NSAIDs, bed rest, traction
  14. 14. Toxic Neuropathies (ICD 357.7*) • Organophosphates • Toxins/Heavy metals – Lead – Arsenic • Chronic uremia – Due to excessive levels of parathormone • Medications (ICD 357.6*) – Antimetabolic/ChemoTx
  15. 15. Diabetic Polyneuropathies (ICD 357.2) • Diabetes affects ~6% of the population • Vascular and neurological complications are the most common causes of morbidity & mortality • Neuropathy affects 25-50% – Directly related to the length of time that nerve fibers are exposed to hyperglycemia – Mixed polyneuropathy – Usually affects motor, sensory & autonomic
  16. 16. Diabetic Neuropathy Syndromes • Glucose becomes incorporated into proteins – AGEs are formed (irreversible) – Reactive oxidants are produced – Cause damage to collagen structure, basement membrane thickening, increased inflammatory responses and vascular permeability
  17. 17. Diabetic Neuropathy Syndromes • Two types: – Peripheral • Focal – Mononeuropathy affecting PNS or CNs • Generalized – Symmetric, peripheral, sensory polyneuropathy – Insidious and progressive – Autonomic • May result in erectile dysfunction, gastropathy, or hypoglycemia • Cardiovascular complications – Orthostatic hypotension – Myocardial infarction – Malignant arrhythmia – Sudden death
  18. 18. Diabetic Neuropathy Syndromes • Focal or multifocal • Occur secondary to vasculitis/ischemia • Acute onset of pain – Resolves spontaneously <6 weeks • May involve: – CN III, IV, VI, VII – Ulnar or median nerve – Peroneal, sural, sciatic, or femoral nerve – Amyotrophy of proximal thigh muscles – Diabetic truncal radiculoneuropathy
  19. 19. Diabetic Neuropathy Syndromes • Can be detected during a routine exam • Inspect feet for deformities and sensory loss – Loss of ankle reflexes – Loss of Hot/Cold sensation – Loss of vibratory sense • 128Hz tuning fork to hallux – Monofilament test • Use 10 gauge monofilament – Charcot foot = xerosis, venous distension, multiple bony deformities • EMG and NCS confirm the diagnosis
  20. 20. Monofilament Test • There is a risk of ulcer formation if the patient is unable to feel the monofilament when it is pressed against the foot with just enough pressure to bend the filament • The patient is asked to say "yes" each time he or she feels the filament • Failure to feel the filament at four of 10 sites is 97 percent sensitive and 83 percent specific for identifying loss of protective sensation
  21. 21. Diabetic Mononeuropathies • CN III or CN VI are commonly affected – NOT associated with pupillary abnormalities • CTS (median neuropathy) – Occurs in ~6% of diabetics – Acute onset of painful paresthesias in fingers with radiating “ache” to forearm • Worse HS • Motor weakness is progressive with thenar wasting • Positive Phalen test and/or Tinel sign
  22. 22. Diabetic Autonomic Neuropathy • GI-related: – Characterized by gastroparesis, nausea/emesis and diarrhea – Improve overall glycemic control** – +/- improvement of GI sx’s with Metoclopramide – Tx diarrhea with Clonidine QD (+/- TCN) • GU-related: – Characterized by impotence, impaired sensation to voiding, and retrograde ejaculation
  23. 23. Treatment of Diabetic Neuropathy Syndromes • Improved metabolic control is the main goal of treatment – Control lipids – Manage HTN (ACE inhibitors) – Lifestyle intervention • Intensive insulin therapy – 3-4 injections QD or an insulin pump reduced electrophysiologic evidence by up to 64% • ASA • Magnesium oxide 250-750mg HS
  24. 24. Treatment of Diabetic Neuropathy Syndromes • Analgesics – Tramadol • Neuromodulators – Gabapentin • Carbamazepine (Tegretol) • Capsaicin – Tx neuropathic pain: rub in for 5 minutes BID • TCAs • Daily foot exam by patient!!! – Use mirrors • Annual PCP examination is required
  25. 25. Diabetic Autonomic Neuropathy • Avoid medications that can cause syncope: – Alpha-blockers, anti-HTN, antidepressants • Frequent accuchecks • Maintain adequate hydration • Minimize cardiac-related AN: – Monitor for orthostatic hypotension • Increased risk of sudden death/silent ischemia – Improve mgmt of glucose, lipids, and HTN – Use ACE inhibitors*
  26. 26. Diabetic Neuropathy Syndromes • Foot ulceration and amputation are the most common consequences • Risk factors for amputation: – Poor glycemic control – Alcohol abuse – Obesity – Loss of protective sensation – Altered biomechanics/foot deformities – Diagnosis >10 years – Gender – Peripheral vascular disease
  27. 27. Neuropathy Disability Score Sensation Score Vibration Apply 128-Hz tuning fork to apex of great toe Normal = can distinguish presence/absence of vibration Abnormal 0 1 Temperature Apply temperature variants to dorsum of foot Normal = can distinguish temperature variants Abnormal 0 1 Pinprick Apply pin proximal to great toenail Normal = can distinguish sharpness Abnormal 0 1 Achilles reflex Present Present with reinforcement Absent 0 1 2 Total for one foot 0-5 A total score (for both feet) of 6 or greater is predictive of foot ulceration.
  28. 28. Alcoholic Polyneuropathy (ICD 357.5) • Establish Dx of alcohol abuse – Preoccupation – Increased tolerance – Drinking alone – Use as a “medication” – Blackouts – Physical/Social/Family issue • CAGE questionnaire • ? Vitamin deficiency
  29. 29. Alcoholic Polyneuropathy • Wernicke-Korsakoff syndrome – CNS injury related to thiamine deficiency – Nystagmus, ataxia, confusion, EOM paralysis • Peripheral polyneuropathy – Earliest symptom of chronic alcoholism – Mostly sensory with +/- motor involvement – “Burning” sensation in feet • Dementia – due to cerebral atrophy • Cerebellar degeneration – truncal ataxia • Myopathy – proximal muscle wasting • Hepatic encephalopathy – Altered consciousness/lethargy – Ataxia/dysarthria/asterixis
  30. 30. Alcoholic Polyneuropathy • Delirium Tremens (DTs) – Alcohol withdrawal syndrome – Occurs 72-96 hours after cessation – Often fatal – Similar to withdrawal from barbiturates/benzos – Mild tremors seizures – “Jittery” and easily startled – Hallucinations – Autonomic hyperactivity
  31. 31. Alcoholic Polyneuropathy • Seizures are common – Generalized (“Rum fits”) • Occur 12-48 hours after decreased ETOH intake – Focal • Occur during periods of intoxication • Tx: – Supportive (diet, vitamins, etc.) – Librium – Diazepam – Thiamine (50mg IV and 50mg IM QD)
  32. 32. Uremic Neuropathy (Uremia) (ICD 357.4) • Presents with altered mental status – Variable – Irritability – Difficulty concentrating – Psychosis • May have convulsions – Secondary to acidosis, hypokalemia, hyponatremia • Often occurs postdialysis/postdiuresis • Most patients with BUN>60 have EEG changes • R/O infection and subdural hematoma
  33. 33. Uremic Neuropathy • Additional (late) symptoms: – Peripheral neuropathy – “Restless leg syndrome” – “Burning” paresthesias of the feet – Sensory loss in digits – Asterixis – Fasciculations – Myoclonus – Muscle cramps – Amaurosis – Cerebral emboli – Dementia
  34. 34. Autonomic Neuropathies • Parasympathetic neuropathies typically involve the cranial nerves or sacral nerves • Sympathetic neuropathies involve the medulla oblongata, spinal cord, or sympathetic ganglia • Both involve receptors in the smooth muscles and glands
  35. 35. Clinical Manifestations of Autonomic Neuropathies • Sudden death • Tremors • Hyperthermia • Altered sweating • Tachycardia • Orthostatic hypotension • Syncope • Gastroparesis • GU dysfunction
  36. 36. Conditions Associated with Autonomic Neuropathies • Poisoning – Atropine – Anticholinesterase inhibitors • Horner’s syndrome – Oculosympathetic paralysis • Ptosis • Miosis • Anhidrosis • Shy-Dragger syndrome – Progressive autonomic failure – Multiple system atrophy – Progressive and fatal
  37. 37. Conditions Associated with Autonomic Neuropathies • Pheochromocytoma – Tumors arising from chromaffin cells in the sympathetic nervous system – Release Epinephrine and NE into circulation – Cause autonomic hyperactivity • Paroxysmal hypertension • Diaphoresis • Flushing • Tachycardia • Anxiety – Test blood/urine for catecholamines, metanephrines and vanillylmandelic acid (VMA)
  38. 38. Assessment of Possible Autonomic Neuropathies • Orthostatic VS • ECG – Look for R-R variability • Tilt test • Cold pressor test • Sweat provocation
  39. 39. Treatment of Neuropathies • Several classes of drugs have recently proved helpful to many patients suffering from more severe forms of chronic neuropathic pain – Antiepileptic drugs • Phenytoin (Dilantin) • Carbamazepine (Tegretol) – Some classes of antidepressants (Tricyclics) – Gabapentin (Neurontin) – Mexiletine (Mexitil) • developed to correct irregular heart rhythms • sometimes associated with severe side effects
  40. 40. Treatment of Neuropathies • Neuropathic pain is often difficult to control – Use smallest effective dose and titrate – Mild pain may sometimes be alleviated by OTC analgesics – Limit narcotic use – Corticosteroids may help reduce inflammation • Injections of local anesthetics such as lidocaine or topical patches containing lidocaine may relieve more intractable pain • In the most severe cases, doctors can surgically destroy nerves – The results are often temporary and the procedure can lead to complications.
  41. 41. Information Resources • Neuropathy Association 60 East 42nd Street Suite 942 New York, NY 10165-0999 http://www.neuropathy.org Tel: 212-692-0662 800-247-6968 Fax: 212-692-0668 • National Chronic Pain Outreach Association (NCPOA) P.O. Box 274 Millboro, VA 24460 http://www.chronicpain.org Tel: 540-862-9437 Fax: 540-862-9485 • American Chronic Pain Association (ACPA) P.O. Box 850 Rocklin, CA 95677-0850 http://www.theacpa.org Tel: 916-632-0922 800-533-3231 Fax: 916-632-3208
  42. 42. Information Resources • Charcot-Marie-Tooth Association (CMTA) 2700 Chestnut Parkway Chester, PA 19013-4867 http://www.charcot-marie-tooth.org Tel: 610-499-9264 800-606-CMTA (2682) Fax: 610-499-7267 • American Pain Foundation 201 North Charles Street Suite 710 Baltimore, MD 21201-4111 http://www.painfoundation.org Tel: 888-615-PAIN (7246) 410-783-7292 Fax: 410-385-1832 • National Foundation for the Treatment of Pain P.O. Box 70045 Houston, TX 77270 http://www.paincare.org Tel: 713-862-9332 Fax: 713-862-9346
  43. 43. Summary • List common neuropathies • Etiologies of common neuropathies • Differentiate between common neuropathies • Discuss treatment options for common neuropathies • List the common toxins which produce neuropathies • Symptoms, signs, and treatments of – Guillain-Barré syndrome – Peroneal Muscular Atrophy – Diabetic neuropathies – Alcoholic neuropathies – Uremic neuropathies – Autonomic neuropathies
  44. 44. Summary • Diabetes mellitus is a leading cause of peripheral neuropathy in the United States • Diabetic Neuropathy Syndromes – Vascular and neurological complications are the most common causes of morbidity & mortality – Foot ulceration and amputation are the most common consequences – CTS (median neuropathy) occurs in ~6% – Improved metabolic control is the main goal of treatment – Daily foot exam by patient is essential
  45. 45. Summary • Alcoholic Neuropathy – Peripheral polyneuropathy is the earliest symptom of chronic alcoholism – Wernicke-Korsakoff syndrome results from CNS injury related to thiamine deficiency – Seizures are common • Uremic Neuropathy – Presents with altered mental status – Often occurs postdialysis/postdiuresis
  46. 46. Summary • Autonomic neuropathies affect receptors in the smooth muscles and glands • Clinical manifestations of autonomic neuropathies include sudden death, hyperthermia, altered sweating, orthostatic hypotension, and gastroparesis • Neuropathic pain is difficult to control

×