Infectious Diseases in Critical Care Medicine

Table 3 Mimics of Meningitis (Continued)

Meningeal mimics Differential features and diagnostic clues

Fundi: choroidal tubercles

CNS: unilateral CN VI abducens palsy, MRI/CT scans: hydrocephalus/arachnoiditis

CSF:

WBCs:< 500

PMNs (early)

Lymphs (later)

Glucose:;(may be normal)

RBCs::

TB smear/cultureþ*80%

Serial CSFs:

Over time;glucose/:protein

Lactic acid::(variably elevated)

.Neurosarcoidosis History: systemic sarcoidosis (bilateral hilar adenopathy/interstitial infiltrates, skin

lesions, uveitis, erythema nodosum, arthritis, hypercalciuria,:ACE levels

Onset: subacute

Fundi: “candle wax drippings”

Cranial nerves: unilateral/bilateral CN VII (facial nerve palsy characteristic also CN

palsies II, VII, VIII, IX, X

CSF:

Lymphs::

Glucose :;

WBCs:< 100

RBCs: none (vs TB or malignancy)

.SLE cerebritis History/signs of SLE (pneumonitis, nephritis, skin lesions)

Onset: subacute

Presentation: seizures/encephalopathy:

Fundi: cytoid bodies/cotton wool spots in fundi

CSF:

CSF ANA:þ

CSF C 4 :;

.LCM Seasonal distribution: fall

History: hamster/mouse/rodent contact

Onset: subacute

Presentation: biphasic “flu-like” illness followed by recovery, then headache, fever,

mental confusion/meningismus, myalgias

CBC:

WBCs:;

Platelets;CSF: resembles aseptic meningitis if glucose normal

Glucose: normal/;

WBCs:>1,000 lymphs

.RMSF Seasonal distribution: spring/fall

History: woods/animal exposure

Onset: sudden

Presentation: severe headache, myalgias, and mild nuchal rigidity

conjunctival suffusion, periorbital edema/edema of dorsum of hands/feet, wrists/

ankles rash

CSF:

WBCs:<100 lymphs

Lactic acid: normal/slightly:

Glucose: normal/;

Protein::(variably)

.Mycoplasma

meningoencephalitis

History: Mycoplasma CAP

Onset: subacute

Presentation: nonexudative pharyngitis, otitis/bullous myringitis, loose stools/

diarrhea, erythema multiforme

Cold agglutinin titers:>1:512

CSF:

Culture forMycoplasma pneumonia:

Abbreviations: CSF, cerebrospinal fluid; CNS, central nervous system; SLE, systemic lupus erythematosus;

PMNs, polymorphonuclear leukocytes; LCM, lymphocytic choriomeningitis; RMSF, Rocky Mountain spotted fever;

HSV, Herpes simplex virus; ACE, angiotensin-converting enzyme; SGOT, serum glutamate oxaloacetate

transaminase; SGPT, serum glutamate pyruvate transaminase; EEG, electroencephalogram; MRI, magnetic

resonance imaging; CT, computed tomography.

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