Editing Polyneuropathy (section)

==Classification==
Polyneuropathies may be classified in different ways, such as by ''cause'',<ref name=thr/> by ''presentation'',<ref name=pat/> or by ''classes'' of polyneuropathy, in terms of which part of the nerve cell is affected mainly: the [[axon]], the [[myelin]] sheath, or the [[cell body]].<ref>{{cite book|last1=Rakel|first1=David|last2=Rakel|first2=Robert E.|title=Textbook of Family Medicine|publisher=Elsevier Health Sciences|isbn=9780323313087|page=1026|url=https://books.google.com/books?id=8huMBgAAQBAJ&q=polyneuropathy+can+be+classified+by+neuron%2C+axon%2C+myelin&pg=PA1026|access-date=26 August 2016|language=en|date=2015-02-02|archive-date=2022-03-19|archive-url=https://web.archive.org/web/20220319083821/https://books.google.com/books?id=8huMBgAAQBAJ&q=polyneuropathy+can+be+classified+by+neuron%2C+axon%2C+myelin&pg=PA1026|url-status=live}}</ref><ref>{{cite book|last1=McCance|first1=Kathryn L.|last2=Huether|first2=Sue E.|title=Pathophysiology: The Biologic Basis for Disease in Adults and Children|publisher=Elsevier Health Sciences|isbn=9780323316071|page=635|url=https://books.google.com/books?id=0fskCwAAQBAJ&q=polyneuropathy+classified+as+axon%2C+myelin+or+neuron&pg=PA635|access-date=26 August 2016|language=en|date=2014-01-30|archive-date=2022-03-19|archive-url=https://web.archive.org/web/20220319083822/https://books.google.com/books?id=0fskCwAAQBAJ&q=polyneuropathy+classified+as+axon%2C+myelin+or+neuron&pg=PA635|url-status=live}}</ref>
[[File:Saltatory Conduction.gif|thumb|300 px|[[Action potential]] propagation in myelinated neurons is faster than in unmyelinated neurons(left)]]
* '''''Distal axonopathy''''', is the result of interrupted function of the peripheral nerves.<ref>{{cite book|editor-last1=Perry|editor-first1=Michael C.|title=The chemotherapy source book|date=2007|publisher=Lippincott Williams & Wilkins|location=Philadelphia, Pa.|isbn=9780781773287|page=241|edition=4th|url=https://books.google.com/books?id=CDADMzS0TKUC&q=Distal+axonopathy&pg=PA241|access-date=26 August 2016|language=en|archive-date=19 March 2022|archive-url=https://web.archive.org/web/20220319083820/https://books.google.com/books?id=CDADMzS0TKUC&q=Distal+axonopathy&pg=PA241|url-status=live}}</ref> It is the most common response of neurons to metabolic or toxic disturbances, and may be caused by metabolic diseases such as [[Diabetic neuropathy|diabetes]], [[kidney failure]], [[connective tissue disease]], deficiency syndromes such as [[malnutrition]] and [[alcoholism]], or the effects of [[toxin]]s or [[pharmaceutical drug|drugs]] such as [[chemotherapy]]. They may be divided according to the type of axon affected (large-fiber, [[Small fiber peripheral neuropathy|small-fiber]], or both). The most distal portions of axons are usually the first to degenerate, and axonal atrophy advances slowly toward the nerve's cell body.  However, if the cause is removed, then regeneration is possible, although the prognosis depends on the duration and severity of the original stimulus{{medical citation needed|date=August 2016}}. People with distal axonopathies usually present with sensorimotor disturbances such as [[amyotrophic lateral sclerosis]]<ref>{{cite journal|last1=Moloney|first1=Elizabeth B.|last2=de Winter|first2=Fred|last3=Verhaagen|first3=Joost|title=ALS as a distal axonopathy: molecular mechanisms affecting neuromuscular junction stability in the presymptomatic stages of the disease|journal=Frontiers in Neuroscience|date=14 August 2014|volume=8|pages=252|doi=10.3389/fnins.2014.00252|pmid=25177267|pmc=4132373|doi-access=free }}</ref>
* '''''Myelinopathy''''', is due to a loss of myelin or of the [[Schwann cells]].<ref>{{cite book|last1=Hankey|first1=Graeme J.|last2=Wardlaw|first2=Joanna M.|author2-link=Joanna Wardlaw|title=Clinical neurology|date=2008|publisher=Manson|location=London|isbn=9781840765182|page=580|url=https://books.google.com/books?id=Q8q7E6EJr7IC&q=myelinopathy+is+disorder+affecting+the+myelin+of+peripheral+nerve&pg=PA580|access-date=26 August 2016|language=en|archive-date=19 March 2022|archive-url=https://web.archive.org/web/20220319083823/https://books.google.com/books?id=Q8q7E6EJr7IC&q=myelinopathy+is+disorder+affecting+the+myelin+of+peripheral+nerve&pg=PA580|url-status=live}}</ref> This demyelination slows down or completely blocks the conduction of [[action potential]]s through the axon of the nerve cell ([[neurapraxia]]).<ref>{{cite book|last1=Goodman|first1=Catherine C.|last2=Fuller|first2=Kenda S.|title=Pathology: Implications for the Physical Therapist|publisher=Elsevier Health Sciences|isbn=9780323266468|page=1597|url=https://books.google.com/books?id=PVBPAQAAQBAJ&q=Myelinopathy%2C%2Caction+potentials+through+the+axon+of+the+nerve+cell&pg=PA1597|access-date=26 August 2016|language=en|date=2013-08-07|archive-date=2022-03-19|archive-url=https://web.archive.org/web/20220319083824/https://books.google.com/books?id=PVBPAQAAQBAJ&q=Myelinopathy%2C%2Caction+potentials+through+the+axon+of+the+nerve+cell&pg=PA1597|url-status=live}}</ref> The most common cause is [[acute inflammatory demyelinating polyneuropathy]] AIDP, the most common form of [[Guillain–Barré syndrome]]<ref>{{Cite web|url=http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=98916|title=Orphanet: Acute inflammatory demyelinating polyradiculoneuropathy|last=RESERVED|first=INSERM US14 – ALL RIGHTS|website=www.orpha.net|access-date=2016-08-26|archive-date=2016-08-27|archive-url=https://web.archive.org/web/20160827090138/http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=98916|url-status=live}}</ref> (although other causes include [[chronic inflammatory demyelinating polyneuropathy]] )<ref>{{Cite web|url=http://www.ninds.nih.gov/disorders/cidp/cidp.htm|title=Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) Information Page: National Institute of Neurological Disorders and Stroke (NINDS)|website=www.ninds.nih.gov|access-date=2016-07-30|archive-date=2016-07-27|archive-url=https://web.archive.org/web/20160727233351/http://www.ninds.nih.gov/disorders/cidp/cidp.htm|url-status=dead}}</ref>
* '''''Neuronopathy''''' is the result of issues in the [[peripheral nervous system]] (PNS) neurons. They may be caused by [[motor neurone disease]]s, [[sensory neuronopathy|sensory neuronopathies]], toxins, or autonomic dysfunction. [[Neurotoxicity|Neurotoxins]] such as [[chemotherapy]] agents may cause neuronopathies.<ref>{{cite journal|last1=Barohn|first1=Richard J.|last2=Amato|first2=Anthony A.|title=Pattern-Recognition Approach to Neuropathy and Neuronopathy|journal=Neurologic Clinics|date=May 2013|volume=31|issue=2|pages=343–361|doi=10.1016/j.ncl.2013.02.001|pmc=3922643|issn=0733-8619|pmid=23642713}}</ref>