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| __NOTOC__ | | __NOTOC__ |
| [[Image:Home_logo1.png|right|250px|link=https://www.wikidoc.org/index.php/Acute_disseminated_encephalomyelitis]] | | [[Image:Home_logo1.png|right|250px|link=https://www.wikidoc.org/index.php/Acute_disseminated_encephalomyelitis]] |
| {{CMG}}; {{AE}} | | {{CMG}}; {{AE}} {{Sujaya}} |
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| ==Overview== | | ==Overview== |
| No one test established the diagnosis of ADEM. Supporting features include an appropriate viral or vaccination history, an appropriate acute neurologic illness, and consistent features on CNS imaging.
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| ==Differential Diagnosis== | | ==Differential Diagnosis== |
| * '''Acute infectious encephalitis''' | | * '''Acute infectious encephalitis''' |
| *:* Herpes simplex virus
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| *:*:* Most common and treatable form of infectious encephalitis
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| *:*:* Usually due to Human herpesvirus 1 (HSV-1), though HSV-2 accounts for 5%
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| *:*:* One-third occur during primary infection
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| *:*:* Most commonly involves the temporal and frontal lobes; speech disorders, bizarre behaviors, and gustatory and olfactory hallucinations are common
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| *:*:* Fever present in 90%. Altered state of consciousness present in most.
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| *:*:* Associated with scattered hemorrhages, CSF red cells
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| *:*:* Treated with acyclovir 10 mg/kg IV q8h; reduces mortality and morbidity if started early enough. Untreated mortality is 70%.
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| *:* Epstein-Barr virus
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| *:* Lyme disease
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| *:* Arborviruses
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| *:*:* Viruses transmitted by arthropods, mosquitos and tick
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| *:*:* Most common in the summer and fall (in contrast to winter and spring presentations of measles, mumps and VZV).
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| *:*:* Present with:
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| *:*:*:* Fever
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| *:*:*:* Headache
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| *:*:*:* Gastrointestinal symptoms
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| *:*:*:* Neurologic disease typically presents day 2 or 3
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| *:*:*:* CSF typically shows elevated protein, a few hundred white blood cells, normal glucose
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| *:*:*:* No specific treatment
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| *:* Eastern equine encephalitis
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| *:*:* Presents with flu-like symptoms, fever, headache, vomiting, seizures, and progressive neurologic disease
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| *:*:* Seen mostly along the east coast of the U.S.
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| *:*:* Mosquito and bird vectors
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| *:*:* Most common in those <15 or >55 years of age
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| *:*:* Most virulent of arborviruses: 70% mortality
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| *:* [[Western equine encephalitis]]
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| *:*:* Mosquito vector
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| *:*:* Young children
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| *:*:* Often asymptomatic
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| *:*:* Western U.S.
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| *:* California encephalitis
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| *:*:* Worldwide
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| *:*:* Most common in school-age children
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| *:*:* Mosquito vector
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| *:*:* Gastrointestinal (GI) symptoms common
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| *:* St. Louis encephalitis
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| *:*:* Wild bird reservoir
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| *:*:* Wild bird – mosquito cycle
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| *:*:* Throughout U.S.
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| *:* Japanese encephalitis
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| *:*:* Flavivirus endemic in Southeast Asia from India to Japan
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| *:*:* Mosquito transmission
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| *:*:* Vaccine available
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| *:* Mycoplasma infection
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| *:* Cytomegalovirus infection
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| *:* Ehrlichiosis
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| *:* Measles
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| *:* VZV/chickenpox
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| *:* Mumps encephalitis
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| *:*:* CNS features present in ~1% of cases
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| *:*:* Not all patients have parotitis
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| *:*:* Most common in winter and spring
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| *:*:* Most patients recover completely, but some patients left with deafness, seizure, and mental retardation
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| *:*:* Confirmed via culture or serology
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| *:* Mycoplasma
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| *:* Bacterial meningoencephalitis
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| *:* Other infectious encephalitidies
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| * '''Acute multiple sclerosis (MS)'''
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| *:* MS may not be possible to exclude, and to some extent depends upon the natural history of the patient’s disease; MS is typically a chronic disease with a recurrent or progressive course, and ADEM is usually an acute monophasic disease. Both diseases are characterized by demyelination; it is acute in ADEM, and sustained or progressive in MS. It is sometimes best to refer to the illness as an “acute demyelinating disease”, until the disease course declares itself.
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| *:* Simultaneous optic nerve, brain and spinal cord involvement, as well as meningismus, drowsiness, coma and seizures, are features suggestive of ADEM instead of MS.
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| *:* Optic nerve involvement is typically bilateral in ADEM, and unilateral in MS. Transverse myelopathy is usually complete in ADEM, and partial in MS.
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| *:* CSF protein is usually elevated in ADEM, and is often normal in MS. CSF lymphocyte counts >50, and CSF polys are also uncommon in MS.
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| *:* In ADEM in contrast to MS, most MRI lesions enhance with gadolinium, suggestive that all lesions are active, and that the disease is therefore monophasic.
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| * '''Hypoxic encephalopathy'''
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| * '''Cerebrovascular disease'''
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| * '''CNS vasculitis'''
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| * '''Lupus cerebritis'''
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| * '''Toxin effect'''
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| * '''Acute toxic hepatoencephalopathy – Reye’s syndrome'''
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| *:* Acute liver and CNS disease in children under 15 years of age, characterized by progressive liver and CNS disease, commonly in association with the use of salicylates.
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| *:* Often follows a viral infection, especially chickenpox or influenza.
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| *:* Patients often present with vomiting and progressive neurologic disease. Hypoglycemia is common. Jaundice is usually not a prominent feature.
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| *:* The liver is enlarged and evidence of liver disease includes elevated transaminases, prothrombin time, and ammonia, hypoglycemia, and metabolic acidosis. Cerebral edema and brain neuronal degeneration occurs.
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| *:* Mitochondria dysfunction occurs in the liver, brain and muscle. Liver cells show microvacuolization, as do renal tubules.
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| *:* Mortality approaches 50%.
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| ==References== | | ==References== |
| {{Reflist|2}} | | {{Reflist|2}} |
