Neuropathies

neuropathies

1. Peripheral Neuropathies Dr Sarah Dawson, 31st July 2014

2. Aims Define neuropathy Describe different neuropathies and identify common disease patterns List a differential diagnosis for each type of neuropathy

3. What is neuropathy? Peripheral neuropathy ( PN ) is damage or disease affecting nerves may impair sensation, movement, gland or organ function, or other aspects of health, depending on the type of nerve affected.

4. Classification Mononeuropathy Mononeuritis multiplex Polyneuropathy Autonomic neuropathy Neuritis

5. Name that neuropathy

6. Mononeuropathies Affe cts one nerve Direct injury to a nerve, ischemia , or inflammation . likely that the cause is a physical compression, localized trauma or infection e.g. carpal tunnel, cubital tunnel "pins-and-needles" sensation of one's "foot falling asleep"

7. Mononeuritis multiplex Simultaneous or sequential involvement of individual noncontiguous nerves, either partially or completely, evolving over days to years asymmetric Typically presenting with acute or subacute loss of sensory and motor function of individual nerves May also cause pain deep, aching pain worse at night frequently in the lower back, hip, or leg In diabetes typically encountered as acute, unilateral, severe thigh pain followed by anterior muscle weakness and loss of knee reflex.

8. Causes Diabetes Mellitus Vasculitides polyarteritis nodosa , Wegener's granulomatosis , Churg–Strauss syndrome Immune -mediated disease Rheumatoid SLE Infections leprosy lyme disease HIV sarcoidosis, amyloidosis cryoglobulinemia chemicals, e.g trichloroethylene and dapsone J ellyfish (rare)

9. Back to… name that neuropathy

10. Patterns of disease in diabetes

11. Polyneuropathy Affects many nerve cells in various parts of the body Symmetrical Progresses slowly Caused by processes affecting the whole body

12. Disease Patterns D istalaxonopathy e.g. diabetes, impaired glucose tolerance, alcohol the cell bodies of neurons remain intact axons are affected in proportion to their length. symptoms occur first and most severely in the feet. Myelinopathy aka Demyelinating disease e.g. Gullain Barre Syndrome myelin sheath around axons is damaged affects the ability of the axons to conduct electrical impulses Neuronopathy affects the cell bodies of neurones directly motor neurones (e.g. motor neurone disease) sensory neurones ( sensory neuronopathy e.g. Herpes Zoster or dorsal root ganglionopathy ).

13. Other causes axonopathy Metabolic disturbance- diabetes Renal failure Connective tissue disease Toxins eg alcohol Malnutrition/ Vitamin deficiencies Infections e.g. Lyme disease Drugs (especially chemo)

14. Allopurinol Amiodarone Ara-C Carboplatin Cisplatin Colchicine Danosine (ddl) Dapsone Disulfiram Docetaxel Etoposide (VP-16) Ethambutol Etoposide Gentamin Gold Indomethacin Isoniazid Lithium L-tryptophan contaminant Mercury Metronidazole Misonidazole Nitrofurantoin Nitrous Oxide Paclitaxel Perhexilene Phenytoin Pyridoxine Sulfapyridine Statins Stavudine (d4T) Streptokinase Suramin Tacrolimus Thalidomide TNF-alpha antagonists Tumor Necrosis Factor Vincristine Zalcitabine (ddC) Zimeldine

15. Autonomic neuropathy Most commonly in latter stages DM Symptoms Urinary-incontinence or retention GI tract: dysphagia , abdominal pain , nausea , vomiting , malabsorption , fecal incontinence , gastroparesis , diarrhoea , constipation CVS disturbances of heart rate orthostatic hypotension , inadequate increase of heart rate on exertion Resp impairments in the signals associated with regulation of breathing and gas exchange ( central sleep apnea , hypopnea , bradypnea ). [5] Also hypoglycemia unawareness, genital impotence, sweat disturbances

16. Last chance to name that neuropathy!

17. Neuritis inflammation of a nerve (mononeuritis) or the peripheral nervous system (polyneuritis)

18. Causes • Physical injury -bad shoes • Infection • Herpes simplex • Shingles • Leprosy • Lyme disease • Chemical injury • Radiation • Underlying conditions causing localised neuritis • Diphtheria • Localised injury • Diabetes • Underlying conditions causing polyneuritis • Beriberi (vit B1deficiency) • Vitamin B12 deficiency • Vitamin B6 excess • Metabolic diseases -DM • Celiac disease • Herpes zoster • Hypothyroidism • Porphyria • Infections, bacterial or viral • Autoimmune disease, especially MS + Guillain- Barre syndrome • Cancer • Alcoholism

19. Summary Neuropathy has several different patterns Early identification of pattern helps target diagnosis, which in turn influences management Diabetes may present with many different disease patterns Causes are diverse from metabolic processes, infection, nutritional deficits, autoimmune disease, drugs, toxins and more

20. Thank you