View source for Meningitis

''This page is for <u>adult</u> meningitis. See [[Meningitis (peds)]] for the pediatric page.''
==Background==
[[File:Meningitis-Epidemics-World-Map.png|thumb|Epidemic meningitis geographic distribution showing "meningitis belt."]]
===Microbiology===
*Bacterial meningitis: 
**[[Pneumococcus]] (60%), [[meningococcus]] (15%), [[group B streptococcus]] (15%), [[H flu]] (7%), [[listeria]] (2%) 
*Viral meningitis
**Echovirus, [[Coxsackie_virus|coxsackies]], enterovirus (85%)
**[[HSV]], [[CMV]], [[Herpes B virus]]

===Pathophysiology===
*Hematogenous spread via respiratory tract 
*Contiguous spread ([[otitis media]], [[sinusitis]], [[brain abscess]])

===Risk Factors===
{{Meningitis risk factors}}

===Classification===
*Acute (<24hr) 
**Usually bacterial in origin (25%) 
*Subacute (1-7d) 
**Viral or bacterial 
*Chronic (>7d) 
**Viral, [[TB]], [[syphilis]], [[fungi]], carcinomatous

==Clinical Features==
Almost all adults present with at least 2 of the following:<ref>van de Beek D. et al. Clinical features and prognostic factors in adults with bacterial meningitis. N Engl J Med. 2004 Oct 28. 351(18):1849-59.</ref>
*[[Headache]]
*[[Fever]] 
*Neck stiffness 
*[[Altered Mental Status]]

Other nonspecific symptoms include:
*Photophobia 
*[[Vomiting]] 
*Prodromal [[URI]] 
*[[Focal neuro|Focal neuro symptoms]] (e.g. [[cranial nerve palsies|CN deficit]]) 
*[[Seizures]]
*Rash
**Approximately 2/3 of patients with [[meningococcemia]] develop rash.<ref>Sara Bode; Contagious Exanthematous Diseases. ''Quick References 2022''; 10.1542/aap.ppcqr.396150</ref>
**Can include erythematous, morbilliform, or urticarial macules and papules<ref>Sara Bode; Contagious Exanthematous Diseases. ''Quick References 2022''; 10.1542/aap.ppcqr.396150</ref>
**Most common hallmark is purpuric lesions with jagged edges. <ref>Sara Bode; Contagious Exanthematous Diseases. ''Quick References 2022''; 10.1542/aap.ppcqr.396150</ref>

==Differential Diagnosis==
{{Headache DDX}}
{{AMS and fever DDX}}

==Evaluation==
===Physical Exam===
{| class="wikitable"
|+Clinical Tests for Meningitis
| align="center" style="background:#f0f0f0;"|'''Finding'''
| align="center" style="background:#f0f0f0;"|'''Description'''
| align="center" style="background:#f0f0f0;"|'''Sensitivity'''
| align="center" style="background:#f0f0f0;"|'''Specificity'''
|-
| Nuchal rigidity||
*Rigidity of neck muscles with flexion
||13%<ref name="Nakao">Nakao JH, et al. Jolt accentuation of headache and other clinical signs: poor predictors of meningitis in adults. Am J Emerg Med. 2014;32(1):24-28.</ref>||80% <ref name="Nakao" />
|-
| Kernig's sign||
*With flexed hip at 90°, extension of knee produces pain
||2%<ref name="Nakao" />||97%<ref name="Nakao" />
|-
| Brudzinski's sign||
*Involuntary lifting of legs with passive flexion of the neck
||2%<ref name="Nakao" />||98%<ref name="Nakao" />
|-
| [[EBQ:Jolt Test|Jolt Test]]||
*Horizontal rotation of the head at frequency of 2 rotations/second
*Exacerbation of pre-existing headache is positive test.
||100%?^||
|}
^Although a 1991 study<ref>Jolt accentuation of headache: the most sensitive sign of CSF pleocytosis. Headache. 1991 Mar;31(3):167-71.</ref> showed high sensitivity with this test, multiple newer studies have cast doubt on its sensitivity.<ref>Absence of jolt accentuation of headache cannot accurately rule out meningitis in adults. Am J Emerg Med. 2013 Nov;31(11):1601-4</ref><ref>Jolt accentuation of headache and other clinical signs: poor predictors of meningitis in adults. Am J Emerg Med. 2014 Jan;32(1):24-8</ref> Although it may be clinically useful in the right subset of patients, it should not be considered to be 100% sensitive.

===Work-Up===
#CBC
#Chem
#Blood culture 
#?CT head: See [[CT Before Lumbar Puncture]]
#[[CXR]] (50% of patients with pneumoccocal meningitis have evidence of pneumonia on CXR) 
#[[Lumbar Puncture]]

===[[Lumbar Puncture]] Diagnosis===
{{Lumbar Puncture Diagnosis}}

====Delay in LP====
*CSF cultures become sterile in '''2 hrs''' after parenteral antibiotics in meningococcal meningitis and '''6 hrs''' in pneumococcal meningitis<ref>Kanegaye JT, Soliemanzadeh P, Bradley JS. Lumbar puncture in pediatric bacterial meningitis: defining the time interval for recovery of cerebrospinal fluid pathogens after parenteral antibotic pretreatment. Pediatrics2001;108:1169–74</ref><ref>Michael B1, Menezes BF, Cunniffe J, Miller A, Kneen R, Francis G, Beeching NJ, Solomon T. Effect of delayed lumbar punctures on the diagnosis of acute bacterial meningitis in adults. Emerg Med J 2010;27:6 433-438. PMID 20360497</ref>
*12 hrs after antibiotics: CSF glucose levels increase and protein levels decrease. CSF WBC and neutrophils are not affected<ref>Lise E. Nigrovic, Richard Malley, Charles G. Macias, John T. Kanegaye, Donna M. Moro-Sutherland, Robert D. Schremmer, Sandra H. Schwab, Dewesh Agrawal, Karim M. Mansour, Jonathan E. Bennett, Yiannis L. Katsogridakis, Michael M. Mohseni, Blake Bulloch, Dale W. Steele, Ron L. Kaplan, Martin I. Herman, Subhankar Bandyopadhyay, Peter Dayan, Uyen T. Truong, Vince J. Wang, Bema K. Bonsu, Jennifer L. Chapman, Nathan Kuppermann. Effect of Antibiotic Pretreatment on Cerebrospinal Fluid Profiles of Children With Bacterial Meningitis. Pediatrics Oct 2008, 122 (4) 726-730. PMID 18829794</ref>

==[[Antibiotics]]==
*''Give as soon as possible (if [[LP]] performed within 2hr of antibiotics, [[CSF]] culture will not be affected)''
{{Meningitis Antibiotics}}


If patient has a cephalosporin allergy, you can replace the third generation cephalosporin with Meropenem or chloramphenicol.

==[[EBQ:De_Gans_-_Steroids_for_Bacterial_Meningitis|Steroids]]==
*[[Dexamethasone]] in adults
**Only give 15 min prior to or with first dose of [[antibiotics]] 
**10mg IV q6hr x4d
*Overall, steroids only decreased mortality in patients with meningitis caused by [[Streptococcus pneumoniae]]<ref>Brouwer MC, McIntyre P, de Gans J, Prasad K, van de Beek D. Corticosteroids for Acute Bacterial Meningitis. Cochrane Database of Systematic Reviews 2010, Issue 9.</ref>
*Steroids did decrease rates of any hearing loss, severe hearing loss, and any neurological sequelae in meningitis caused by all species
**This benefit was present in high-income countries but not in low-income countries
*[[Dexamethasone]] in children and infants
**There has been no mortality benefit found with steroid use in children<ref>Mongelluzzo J, Mohamad Z, Ten Have TR, et al. Corticosteroids and mortality in children with bacterial meningitis. JAMA. 2008. 299(17):2048-2055.</ref>
**Steroids decreased the rate of hearing loss in children with meningitis caused by [[Haemophilus influenzae]]<ref>Brouwer MC, McIntyre P, de Gans J, Prasad K, van de Beek D. Corticosteroids for Acute Bacterial Meningitis. Cochrane Database of Systematic Reviews 2010, Issue 9.</ref>
*[[Hydrocortisone]] for [[adrenal insufficiency|adrenal failure]] (Waterhouse–Friderichsen syndrome, bilateral adrenal hemorrhage causing adrenal failure, seen in meningococcemia)

==Antivirals==
*[[Acyclovir]]
**Consider for patients with suspected viral meningitis who present with neurologic deficits
**10mg/kg IV q8hr (Obese patients should be dosed using [[ideal body weight estimation|ideal body weight]])

==Other Considerations==
*Inpatient team may consider MRI with MRV for further diagnostic considerations
*If there is concern for tick-borne illness, it may be prudent to add [[doxycycline]] before ID consult can occur

==Prophylaxis==
{{Neisseria meningitis post exposure prophylaxis}}

==Disposition==
===Bacterial meningitis===
*Admit with [[droplet precautions]]

===Viral meningitis===
*Admit for empiric [[antibiotics]] until culture results return '''OR'''
*Discharge with 24hr follow up

==See Also==
*[[Meningitis (peds)]]
*[[Neoplastic meningitis]]

==References==
<references/>

[[Category:ID]]
[[Category:Neurology]]