VZV encephalitis: Difference between revisions

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#REDIRECT [[Varicella zoster encephalitis]]
{{CMG}} {{AE}} {{AG}}
 
{{SK}} Varicella zoster virus encephalitis; Herpes zoster encephalitis; Varicella zoster encephalitis; Varicella encephalitis;
 
==Overview==
 
==Classification==
Based on the duration of symptoms, VZV encephalitis may be classified into either acute or chronic.
 
==Pathophysiology==
The exact pathogenesis of VZV encephalitis is not fully understood. It is known that VZV encephalitis is the result of the [[varicella zoster virus]], a double-stranded [[DNA virus]] within the [[Herpesviridae]] family of viruses.<ref name=Mandell1> M.D. JE, Dolin R, Blaser MJ. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, Expert Consult Premium Edition. Saunders; 2014.</ref> The [[immune system]] eliminates the virus from most locations, but it remains [[viral latency|latent]] in the [[dorsal root ganglion]] and the [[trigeminal]] ganglion near the base of the skull. Initial infection by VZV presents as [[chickenpox]], often in children between 1-9. VZV reactivation, which presents as [[shingles]] in adults, is the result of a decline in the frequency of VZV-specific [[T cell]]s.<ref name="pmid9300702">{{cite journal| author=Sadzot-Delvaux C, Kinchington PR, Debrus S, Rentier B, Arvin AM| title=Recognition of the latency-associated immediate early protein IE63 of varicella-zoster virus by human memory T lymphocytes. | journal=J Immunol | year= 1997 | volume= 159 | issue= 6 | pages= 2802-6 | pmid=9300702 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=9300702  }} </ref> The molecular basis of reactivation remains unknown.<ref name=Mandell1> M.D. JE, Dolin R, Blaser MJ. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, Expert Consult Premium Edition. Saunders; 2014.</ref> Some histopathologic studies suggest of a postinfectious [[demyelinating]] process, while other findings cite direct viral cytopathology.<ref name="pmid6326714">{{cite journal| author=Bauman ML, Bergman I| title=Postvaricella encephalitis. | journal=Arch Neurol | year= 1984 | volume= 41 | issue= 5 | pages= 556-8 | pmid=6326714 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=6326714  }} </ref><ref name="pmid4311227">{{cite journal| author=McCormick WF, Rodnitzky RL, Schochet SS, McKee AP| title=Varicella-Zoster encephalomyelitis. A morphologic and virologic study. | journal=Arch Neurol | year= 1969 | volume= 21 | issue= 6 | pages= 559-70 | pmid=4311227 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=4311227  }} </ref><ref name="pmid582251">{{cite journal| author=Takashima S, Becker LE| title=Neuropathology of fatal varicella. | journal=Arch Pathol Lab Med | year= 1979 | volume= 103 | issue= 5 | pages= 209-13 | pmid=582251 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=582251  }} </ref>
 
==Causes==
VZV encephalitis may be caused by either varicella ([[chickenpox]]) or herpes zoster ([[shingles]]).
 
==Differentiating VZV Encephalitis from Other Diseases==
VZV encephalitis must be differentiated from other diseases that cause [[fever]], [[headache]], [[vomiting]], and [[altered mental status]], such as:<ref name="pmid14978145">{{cite journal| author=Kennedy PG| title=Viral encephalitis: causes, differential diagnosis, and management. | journal=J Neurol Neurosurg Psychiatry | year= 2004 | volume= 75 Suppl 1 | issue=  | pages= i10-5 | pmid=14978145 | doi= | pmc=PMC1765650 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=14978145  }} </ref><ref name="pmid12353193">{{cite journal| author=Gnann JW| title=Varicella-zoster virus: atypical presentations and unusual complications. | journal=J Infect Dis | year= 2002 | volume= 186 Suppl 1 | issue=  | pages= S91-8 | pmid=12353193 | doi=10.1086/342963 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12353193  }} </ref><ref name="pmid13065322">{{cite journal| author=APPELBAUM E, RACHELSON MH, DOLGOPOL VB| title=Varicella encephalitis. | journal=Am J Med | year= 1953 | volume= 15 | issue= 2 | pages= 223-30 | pmid=13065322 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=13065322  }} </ref>
 
{| style="border: 0px; font-size: 90%; margin: 3px;" align=center
|+
! style="background: #4479BA; width: 120px;" | {{fontcolor|#FFF|Disease}}
! style="background: #4479BA; width: 550px;" | {{fontcolor|#FFF|Findings}}
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| style="padding: 5px 5px; background: #DCDCDC;" | '''Other [[Viral encephalitis]] '''
| style="padding: 5px 5px; background: #F5F5F5;" | Presents with acute [[inflammation]] of the [[brain]], caused by a [[viral infection]]; it may complicate into severe [[brain]] damage as the inflamed [[brain]] pushes against the [[skull]], potentially leading to [[mortality]]. {{see also|Herpes simplex encephalitis|West Nile encephalitis|St. Louis encephalitis|Japanese encephalitis}}
|-
| style="padding: 5px 5px; background: #DCDCDC;" | '''[[Bacterial encephalitis]]'''
| style="padding: 5px 5px; background: #F5F5F5;" | Presents with acute [[inflammation]] of the [[brain]], caused by a [[bacterial infection]]; it may complicate into severe [[brain]] damage as the inflamed [[brain]] pushes against the [[skull]], potentially leading to [[mortality]]. {{see also|Tick-borne encephalitis}}
|-
| style="padding: 5px 5px; background: #DCDCDC;" | '''[[Encephalopathy]]'''
| style="padding: 5px 5px; background: #F5F5F5;" | Presents with steady [[depression]], generalized [[seizures]]. Generally absent are [[fever]], [[headache]], [[leukocytosis]], and [[pleocytosis]]; [[MRI]] often appears normal.
|-
| style="padding: 5px 5px; background: #DCDCDC;" | '''[[Meningitis]]'''
| style="padding: 5px 5px; background: #F5F5F5;" |Presents with [[headache]], [[altered mental status]], and [[inflammation]] of the [[meninges]], which may develop in the setting of an [[infection]], physical injury, [[cancer]], or certain drugs; it may have an indolent evolution, resolving on its own, or may present as an rapidly evolving [[inflammation]], causing neurologic damage and possible [[mortality]]. {{see also|bacterial meningitis|viral meningitis|fungal meningitis}}
|-
| style="padding: 5px 5px; background: #DCDCDC;" |'''[[Brain abscess]]'''
| style="padding: 5px 5px; background: #F5F5F5;" |Presents with an [[abscess]] in the [[brain]] caused by the [[inflammation]] and accumulation of [[infected]] material from local or remote infectious areas of the body; the infectious agent may also be introduced as a result of head [[trauma]] or [[neurosurgery|neurological procedures]].
|-
| style="padding: 5px 5px; background: #DCDCDC;" | '''[[Acute disseminated encephalomyelitis]]'''
| style="padding: 5px 5px; background: #F5F5F5;" | Presents with scattered foci of [[demyelination]] and perivenular [[inflammation]]; it can cause focal neurological signs and decreased ability to focus.
|-
|}
 
==Epidemiology and Demographics==
 
==Risk Factors==
disease arises from various events which depress the [[immune system]], such as aging, severe emotional stress, severe illness, [[immunosuppression]] or long-term use of [[corticosteroid]]s.<ref name="Mounsey">{{cite journal|title=Herpes zoster and postherpetic neuralgia: prevention and management|author=Mounsey AL, Matthew LG, & Slawson DC|date=2005|journal=American Family Physician|volume=72|issue=6|pages=1075-1080|pmid=16190505|url=http://www.aafp.org/afp/20050915/1075.html|accessdate=2007-06-15}}</ref><ref>{[cite journal|title=What does epidemiology tell us about risk factors for herpes zoster?|author=Thomas SL, Hall AJ|journal= Lancet Infect Dis.|date=2004|volume=4|issue=1|pages=26-33|pmid= 14720565}}</ref>  The cellular and immunological events that lead to reactivation are poorly understood.<ref>Donahue JG, Choo PW, Manson JE, Platt R (1995). "The incidence of herpes zoster". Arch. Intern. Med 155 (15): 1605–9. PMID 7618983</ref> There have been recorded cases of outbreaks occurring due to unmanaged stress or other stresses to the skin such as pinching, biting or scratching of  more sensitive areas, such as nipples, ears, and underarms.
 
 
==Natural History, Complications, and Prognosis==
 
==Diagnosis==
 
===History and Symptoms===
 
===Physical Examination===
 
===Laboratory Findings===
 
===CT===
 
===MRI===
 
==Treatment==
 
===Medical Therapy===
 
===Prevention===
 
==References==
{{reflist|2}}
 
[[Category:Primary care]]
[[Category:Viral diseases]]
[[Category:Infectious disease]]
[[Category:Neurology]]

Latest revision as of 20:02, 1 August 2016