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'''[[Sindrome dell'occhio fantasma]]'''
'''[[:en:Phantom eye syndrome]]'''
=[[:en:SN 1979C]]=</noinclude>
=='''[[Sindrome dell'occhio fantasma]]'''==
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{{Infobox Malattia
|Nome=Sindrome dell'occhio fantasma
|Immagine=Gray889.png
|Didascalia=Anatomia dell'[[occhio]]. I muscoli esterni sono segnati in rosso.
|ICD9={{ICD9|353.6}}
|ICD10={{ICD10|G|54|6|g|50}}, {{ICD10|G|54|7|g|50}}
}}
{{Utente:Vale maio/Sandbox5|{{Utente:Vale maio/Sandbox7|7}}}}
La '''sindrome dell'occhio fantasma''' è un dolore fantasma all'occhio, con possibili [[allucinazioni]], che si può manifestare dopo la rimozione dell'occhio.
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==Sintomatologia==
Template inclusi:
*[[Utente:Vale maio/Sandbox7]] ([[:en:Template:MONTHABBREV]])
Molti pazienti lamentano uno o più fenomeni fantasma dopo la rimozione dell'occhio:
*[[Utente:Vale maio/Sandbox8]] ([[:en:Template:MONTHNUMBER]])
* Dolore fantasma all'occhio rimosso (prevalenza del 26%)<ref name="Soros1">{{cita pubblicazione |quotes= |cognome=Sörös |nome=P. |linkautore= |coautori=O. Vo, I.-W. Husstedt, S. Evers, H. Gerding |anno=2003 |mese=Maggio |titolo=hantom eye syndrome: Its prevalence, phenomenology, and putative mechanisms |rivista=Neurology |volume=60 |numero=9 |pagine=1542-3 |id=12743251 |url=http://www.neurology.org/cgi/pmidlookup?view=long&pmid=12743251 |lingua={{en}} |accesso= |abstract= }}</ref>;
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*sensazioni fantasma di natura non dolorosa<ref name="Soros1"/>;
*[[allucinazioni]] visive: circa il 30% dei pazienti accusa allucinazioni dall'occhio rimosso<ref name="Soros1"/>. La maggior parte di queste allucinazioni consiste in percezioni visive di base (forme e colori). Al contrario, allucinazioni visive causate da perdite della vista sono meno comuni (casistica del 10% circa), e consistono spesso in immagini dettagliate.
== Pathogenesis ==
=== Phantom pain and non-painful phantom sensations ===
Phantom pain and non-painful phantom sensations result from changes in the central nervous system due to denervation of a body part.<ref name="Ramachandran">{{cite journal |first=Vilayanur S. |last=Ramachandran |authorlink=Vilayanur S. Ramachandran |coauthors=W Hirstein |title=The perception of phantom limbs. The D. O. Hebb lecture |journal=[[Brain (journal)|Brain]] |volume=121 |issue=9 |pages=1603–30 |year=1998 |month=September |pmid=9762952 |doi= 10.1093/brain/121.9.1603|url=http://brain.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=9762952 |accessdate=2008-09-23}}</ref><ref name="Nikolajsen">{{cite journal |first=L. |last=Nikolajsen |coauthors=T. S. Jensen |title=Phantom limb pain |journal=[[British Journal of Anaesthesia]] |volume=87 |issue=1 |pages=107–16 |year=2001 |month=July |pmid=11460799 |doi= 10.1093/bja/87.1.107|url=http://bja.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=11460799 |accessdate=2008-09-23}}</ref> Phantom eye pain is considerably less common than phantom limb pain. The prevalence of phantom pain after limb [[amputation]] ranged from 50% to 78%. The prevalence of phantom eye pain, in contrast, is about 30%.
Post-amputation changes in the [[Cortical homunculus|cortical representation of body parts]] adjacent to the amputated limb are believed to contribute to the development of phantom pain and nonpainful phantom sensations. One reason for the smaller number of patients with phantom eye pain compared with those with phantom limb pain may be the smaller cortical [[somatosensory]] representation of the eye compared with the limbs.
In limb amputees, some<ref name="Nikolajsen">{{cite journal |author=Nikolajsen L, Ilkjaer S, Krøner K, Christensen JH, Jensen TS |title=The influence of preamputation pain on postamputation stump and phantom pain |journal=Pain |volume=72 |issue=3 |pages=393–405 |year=1997 |month=September |pmid=9313280 |doi= 10.1016/S0304-3959(97)00061-4|url=http://linkinghub.elsevier.com/retrieve/pii/S0304395997000614 |accessdate=2008-09-23}}</ref> but not all studies have found a correlation between preoperative pain in the affected limb and postoperative phantom pain. There is a significant association between painful and nonpainful phantom experiences and preoperative pain in the symptomatic eye and [[headache]].<ref name="Nicolodi">{{cite journal |first=M. |last=Nicolodi |coauthors=R. Frezzotti, A. Diadori, A. Nuti and F. Sicuteri |title=Phantom eye: features and prevalence. The predisposing role of headache |journal=Cephalalgia |volume=17 |issue=4 |pages=501–4 |year=1997 |month=June |pmid=9209770 |doi= 10.1046/j.1468-2982.1997.1704501.x|url=http://www.blackwell-synergy.com/openurl?genre=article&sid=nlm:pubmed&issn=0333-1024&date=1997&volume=17&issue=4&spage=501 |accessdate=2008-09-23}}</ref> Based on the present data it is difficult to determine if headaches or preoperative eye pain play a causal role in the development of phantom phenomena, or if headache, preoperative eye pain, and postoperative phantom eye experiences are only epiphenomena of an underlying factor. However, a study in humans demonstrated that experimental pain leads to a rapid reorganization of the [[somatosensory cortex]].<ref name="Soros2">{{cite journal |first=Peter |last=Sörös |coauthors=Stefan Knechta, Carsten Bantelb, Tanya Imaia, Rainer Wüstenb, Christo Pantevc, Bernd Lütkenhönerc, Hartmut Bürkleb and Henning Henningsen |title=Functional reorganization of the human primary somatosensory cortex after acute pain demonstrated by magnetoencephalography |journal=Neuroscience Letters |volume=298 |issue=3 |pages=195–8 |year=2001 |month=February |pmid=11165440 |doi= 10.1016/S0304-3940(00)01752-3|url=http://linkinghub.elsevier.com/retrieve/pii/S0304394000017523 |accessdate=2008-09-23}}</ref> This study suggests that preoperative and postoperative pain may be an important cofactor for somatosensory reorganization and the development of phantom experiences.
===Visual hallucinations===
Enucleation of an eye and, similarly, retinal damage, lead to a cascade of events in the cortical areas receiving visual input. Cortical [[GABA]]ergic (GABA: Gamma-aminobutyric acid) inhibition decreases and cortical [[glutamate]]rgic excitation increases, followed by increased visual excitibility or even spontaneous activity in the [[visual cortex]].<ref name="Eysel">{{cite journal |first=Ulf T. |last=Eysel |coauthors=Georg Schweigart, Thomas Mittmann, Dirk Eyding, Ying Qu, Frans Vandesande, Guy Orban and Lutgarde Arckens |title=Reorganization in the visual cortex after retinal and cortical damage |journal=Restorative Neurology and Neuroscience |volume=15 |issue=2-3 |pages=153–64 |year=1999 |pmid=12671230 |doi= |url=http://iospress.metapress.com/openurl.asp?genre=article&issn=0922-6028&volume=15&issue=2&spage=153 |accessdate=2008-09-23}}</ref> It is believed that spontaneous activity in the denervated visual cortex is the neural correlate of visual hallucinations.
== See also ==
*[[Visual system]]
*[[Charles Bonnet syndrome]]
==References==
{{reflist}}
==External links==
*{{cite web |url=http://www.wellcome.ac.uk/en/pain/microsite/medicine2.html |title=Phantom limb pain |accessdate=2008-09-23 |publisher=[[Wellcome Trust]] |first=Jonathan |last=Cole}}
*<nowiki>http://psy.ucsd.edu/chip/ramabio.html</nowiki>{{Dead link|date=September 2008}} Homepage of [[Vilayanur S. Ramachandran]]
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[[Category:Visual system]]
[[Category:Neurology]]
[[Category:Neurological disorders]]
[[Category:Ophthalmology]]
[[Category:Syndromes]]
[[hr:Sindrom fantomskog oka]]</nowiki>
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