Encephalitis: Difference between revisions
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*New psychiatric symptoms (HSV)<ref>Loring KE, Tintinalli JE: Central Nervous System and Spinal Infections, in Tintinalli JE, Kelen GD, Stapczynski JS (eds): Emergency Medicine, A Comprehensive Study Guide, ed 7. New York, McGraw-Hill, 2011, (Ch) 168:p 1175-1176.</ref> | *New psychiatric symptoms (HSV)<ref>Loring KE, Tintinalli JE: Central Nervous System and Spinal Infections, in Tintinalli JE, Kelen GD, Stapczynski JS (eds): Emergency Medicine, A Comprehensive Study Guide, ed 7. New York, McGraw-Hill, 2011, (Ch) 168:p 1175-1176.</ref> | ||
*Cognitive deficits | *Cognitive deficits | ||
**Aphasia, amnesia, confusion | **Aphasia, amnesia, [[confusion]] | ||
*[[Seizure]] | *[[Seizure]] | ||
*Movement disorder (arboviruses) | *Movement disorder (arboviruses) | ||
*[[Fever]] and meningeal signs are almost always present | *[[Fever]] and meningeal signs are almost always present | ||
*[[Dysuria]] and pyuria (St. Louis encephalitis) | *[[Dysuria]] and pyuria (St. Louis encephalitis) | ||
*Extreme lethargy (West Nile encephalitis) | *Extreme [[lethargy]] (West Nile encephalitis) | ||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
*[[SAH]] | *[[SAH]] | ||
*[[Lyme disease]] | *[[Lyme disease]] | ||
*Brain abscess | *[[Brain abscess]] | ||
*Bacterial [[endocarditis]] | *Bacterial [[endocarditis]] | ||
*Toxic / metabolic encephalopathy | *Toxic / metabolic encephalopathy | ||
| Line 33: | Line 33: | ||
==Evaluation== | ==Evaluation== | ||
*Imaging identifies abnormalities in medial temporal and inferior frontal gray matter in HSV<ref>Howes DS et al. Encephalitis Workup. Oct 12, 2015. http://emedicine.medscape.com/article/791896-workup#showall</ref> | *Imaging identifies abnormalities in medial temporal and inferior frontal gray matter in HSV<ref>Howes DS et al. Encephalitis Workup. Oct 12, 2015. http://emedicine.medscape.com/article/791896-workup#showall</ref> | ||
**CT Head - edema and petechial hemorrhage | **[[head CT|CT Head]] - edema and petechial hemorrhage | ||
**MRI - increased T2 intensity | **[[brain MRI|MRI]] - increased T2 intensity | ||
*[[LP]] | *[[LP]] | ||
**Bloody tap consistent with HSV | **Bloody tap consistent with HSV | ||
Revision as of 00:28, 2 October 2019
Background
- Infection of brain parenchyma of the temporal lobes and inferior frontal lobe causing distinct neurologic abnormality
- Pathophysiology
- Gray matter is predominantly affected (cognitive / psychiatric signs, lethargy, seizure)
Microbiology
Clinical Features
- New psychiatric symptoms (HSV)[2]
- Cognitive deficits
- Aphasia, amnesia, confusion
- Seizure
- Movement disorder (arboviruses)
- Fever and meningeal signs are almost always present
- Dysuria and pyuria (St. Louis encephalitis)
- Extreme lethargy (West Nile encephalitis)
Differential Diagnosis
- SAH
- Lyme disease
- Brain abscess
- Bacterial endocarditis
- Toxic / metabolic encephalopathy
Altered mental status and fever
- Infectious
- Sepsis
- Meningitis
- Encephalitis
- Cerebral malaria
- Brain abscess
- Other
Evaluation
- Imaging identifies abnormalities in medial temporal and inferior frontal gray matter in HSV[3]
- LP
- Bloody tap consistent with HSV
Management
Often it is unclear which type of encephalitis is present and starting Acyclovir empirically is appropriate. In addition to the pathogens below, possible causes can include West Nile Virus, EBV, HIV, toxoplasmosis, or rabies.
HSV encephalitis
- Acyclovir 10mg/kg (10-15mg/kg for pediatrics) every 8hrs
HZV encephalitis
- Acyclovir 10mg/kg every 8hr
CMV encephalitis
- Ganciclovir 5mg/kg IV every 12hr OR
- Foscarnet 90mg/kg IV every 12 hrs
Tick Associated (Borrelia burgdorferi, Ehrlichiosis or Rickettsia)
- Doxycycline 200 mg IV once followed by 100 mg IV twice daily
Disposition
Admit in all cases
See Also
References
- ↑ Somand D, Meurer W. Central Nervous System Infections. EMCNA 2009; 27: 89-100.
- ↑ Loring KE, Tintinalli JE: Central Nervous System and Spinal Infections, in Tintinalli JE, Kelen GD, Stapczynski JS (eds): Emergency Medicine, A Comprehensive Study Guide, ed 7. New York, McGraw-Hill, 2011, (Ch) 168:p 1175-1176.
- ↑ Howes DS et al. Encephalitis Workup. Oct 12, 2015. http://emedicine.medscape.com/article/791896-workup#showall