CNS Infections 2014

CNS INFECTIONS DR. RABO NEUROLOGY 2014

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LUMBAR PUNCTURE/ LUMBAR TAP and CSF

Indications for Lumbar Puncture

1. To obtain pressure measurements and procure a

sample of the CSF for cellular, cytologic, chemical,

and bacteriologic examination.

2. To aid in therapy by the administration of spinal

anesthetics and occasionally antibiotics or

antitumor agents, or by reduction of CSF pressure.

3. To inject a radiopaque substance, as in

myelography, or a radioactive agent, as in

radionuclide cisternography. CONTRAST IMAGING

Technique of Lumbar Puncture

Could be: a.) fetal position, lateral decubitus usual

b.) sitting position for obese patients

For adult: spinal cord ends at L1 and L2

easiest to perform at the L3-L4 interspace,

which corresponds to the axial plane of the

iliac crests, or at the space above or below

*ASIS guide

the tighter the fetal position, the easier the

entry into the subarachnoid space

For infants and young children

spinal cord may extend to the level of the

L3-L4 interspace, lower spaces should be

used.

Complications of Lumbar Puncture

1. Headache

which has been estimated to occur in one-

third of patients

pain is presumably the result of a reduction

of CSF pressure and tugging on cerebral and

dural vessels as the patient assumes the

erect posture

*stretching of blood vessels (pooling of dural

veins)

2. Bleeding

Bleeding into the spinal meningeal spaces

can occur in patients who are taking

anticoagulants (check PT, bleeding time,

etc.)

Not common

3. Infection rare; technique not aseptic

CSF Analysis

The gross appearance of the fluid is noted, after which

the CSF, in separate tubes, can be examined for:

1. Pressure and Dynamics

CSF pressure is measured by a manometer

attached to the needle in the subarachnoid

space

In the normal adult, the opening pressure

varies from 100 to 180 mmH2O, or 8 to 14

mmHg. In children, the pressure is in the

range of 30 to 60 mmH2O.


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2. Gross Appearance and Pigments

Normally the CSF is clear and colorless, like

water

The presence of red blood cells imparts a

hazy or ground-glass appearance at least

200 red blood cells (RBCs) per cubic

millimeter (mm3) must be present to detect

this change.

The presence of 1000 to 6000 RBC per cubic

millimeter imparts a hazy pink to red color,

depending on the amount of blood

Centrifugation of the fluid or allowing it to

stand causes sedimentation of the RBC.

Several hundred or more white blood cells

in the fluid (pleocytosis) may cause a slight

opaque haziness.

3. Cellularity

The CSF normally contains no cells or at

most up to five lymphocytes or other

mononuclear cells per cubic millimeter, NO

NEUTROPHILS

An elevation of WBC in the CSF always

signifies a reactive process to bacteria or

other infectious agents, blood, chemical

substances, an immunologic inflammation,

a neoplasm, or vasculitis

4. Proteins

lumbar spinal fluid is 45 mg/dL or less in the

adult

5. Glucose

Normally the CSF glucose concentration is

in the range of 45 to 80 mg/dL, i.e., about

two-thirds of that in the blood

Compare value of CSF glucose with serum

glucose, if there is 50% deficiency, consider

it significant


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Bacterial

Meningitis

Viral Meningitis Fungal

Meningitis

Increase

pressure

Normal or

Increase

pressure

Increase

pressure

Purulent Clear Turbid/yellowish

(never colorless)

Increase

lymphocyte;

PMN

predominance

Increase

lymphocyte

Increase

lymphocyte

Protein increase

Sugar decrease

Protein and

Sugar normal

Protein increase

Sugar decrease

In lumbar tap, make sure that there are no

signs of intracranial pressure, it there is, do

neuroimaging instead.

Signs of increased ICP:

Papilledema

Headache with altered sensorium

Cushings triad:

Hypertension

Bradycardia

Bradypnea

Focal neurologic deficits

*headache and vomiting suspect only if there is

altered neurologic sensation

ACUTE BACTERIAL MENINGITIS

Acute purulent infection within the

subarachnoid space. It is associated with a CNS

inflammatory reaction that may result in

decreased consciousness, seizures, raised ICP

and stroke.

The meninges, the subarachnoid space, and the

brain parenchyma are all frequently involved in

the inflammatory reation (meningoencephalitis)

ETIOLOGY

S. pneumonia

MC cause in adults >20 yrs of age

Predisposing conditions

i. Coexisting acute or chronic

pneumococcal sinusitis or otitis media

ii. Alcoholism

iii. Diabetes

iv. Splenectomy

v. Hypogammaglobulinemia

vi. Complement deficiency

vii. Head trauma with basilar skull fracture

and CSF rhinorrhea

N. meningitides

Initiated by nasopharyngeal

colonization, which can result in either

an asymptomatic carrier state or

invasive meningococcal state

Streptocci spp, gram negative anaerobes, S.

aureus, Haemiphilus sp & enterobacteriaceae

otitis, mastoiditis & sinusitis

Group B streptococcus & S. agalactiae

L. monocytogenes

H. influenza


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S. autreus & CONS

PATHOPHYSIOLOGY

CLINICAL PRESENTATION

Triad: fever, headache, nuchal rigidity (may not

be present)

Altered LOC

Seizure

Increased ICP

DIAGNOSIS

CSF analysis

Bacterial meningitis:

PMN leukocytosis (>100 cells/uL)

glucose concentration (


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TREATMENT

S.pneumoniae & N. meningigitides

MC cause of community acquired Bacterial meningitis

Community-acquired suspected bacterial meningitis

dexamethasone + 3rd or 4th generation cephalosphorin and vancomycin, + acyclovir (HSV encep) and Doxycycline (tp prevent tock-borne bacterial infection)

Specific Antimicrobial therapy

Meningococcal meningitis

DOC: PenG

Prophylaxis for close contacts:

o Rifampicin 600mg q12h x2days and

10mg/kg q12h x 2days in children

>1y/0. (CI in pregnant women) OR

o Azithromycin 500mg single dose

o Ceftriaxone 250 mg IM single dose

Pneumococcal meningitis

cephalosphorin and vancomycin Listeria meningitis

ampicillin for atleast 3 weeks

gentamicin is added for critically ill paytient

for penicillin allergic: TMP-SMX q6h staphylococcal meningitis

CONS or susceptible S.aureus: nafcillin

MRSA: DOC Vancomycin Gram (-) bacillary meningitis

3rd gen cephalosphorin cefotaxime, ceftriaxone, ceftazidime

P. aeruginosa: ceftazidime, cefipime meropenem

Adjunctive therapy

Dexamethasone

Given 20 mins prior to administration of antibiotics

Inhibits release of TNF a by macrophages and microglia

Increased ICP

Elevation of head 30-45

Intubation & hyperventilation

Mannitol Poor Prognosis

1. Decreased level of consciousness on admission 2. Onset of seizures within 24 h of admission 3. Signs of increased ICP 4. Young age (infancy) and age >50


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5. The presence of comorbid conditions including shock and/or the need for mechanical ventilation.

6. Delay in the initiation of treatment. Decreased CSF glucose concentration [ 300 mg/dL)] have been predictive of increased mortality and poorer outcomes in some series.

ACUTE VIRAL MENINGITIS

CLINICAL MANIFESTATIONS

Headache - usually frontal or retroorbital and is often associated with photophobia and pain

on moving the eyes. Fever

Signs of Meningeal irriation

CSF profile:

mild lethargy or drowsiness

constitutional signs can include malaise, myalgia, anorexia, nausea and vomiting, abdominal pain, and/or diarrhea

ETIOLOGY

LABORATORY DIAGNOSIS

1. CSF PROFILE

lymphocytic pleocytosis (25500 cells/ L), a normal or slightly elevated protein concentration [0.20.8 g/L (2080 mg/dL)], a normal glucose concentration, and a normal or mildly elevated opening pressure (100350 mmH2O).

2. PCR 3. Viral culture 4. Serology

DDx

1. Untreated or partially treated bacterial meningitis predominantly lymphocytic

2. early stages of meningitis caused by fungi, mycobacteria, or treponema pallidum (neurosyphilis), in which a lymphocytic pleocytosis is common, cultures may be slow growing or negative, and hypoglycorrhachia may not be present early

3. meningitis caused by agents such as mycoplasma, listeria spp., brucella spp., coxiella spp., leptospira spp., and rickettsia spp.;

4. Parameningeal infections; 5. Neoplastic meningitis 6. Meningitis secondary to noninfectious

inflammatory diseases, including hypersensitivity meningitis, sle and other rheumatologic diseases, sarcoidosis, Behet's syndrome, and the uveomeningitic syndromes.

SPECIFIC VIRAL ETIOLOGIES Enterovirus

MC viral meningitis

Tx is supportive Arbovirus HSV2 meningitis

MC in Philippines

Dx thru CSF PCR

Most cases of recurrent viral or "aseptic" meningitis, including cases previously diagnosed as Mollaret's meningitis, are likely due to HSV.


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VZV meningitis EBV Mumps LCMV Treatment

1. Symptomatic a. Analgesics b. Antipyretics c. Antiemetics

2. F&E monitoring 3. Empirical treatment while waiting for the

results of culture 4. Acyclovir 800 mg 5x a day

VIRAL ENCEPHALITIS

In contrast to viral meningitis, where the infectious process and associated inflammatory response are limited largely to the meninges, in encephalitis the brain parenchyma is also involved. CLINICAL MANIFESTATIONS

Acute febrile illness with evidence of meningeal involvement characteristic of meningitis, the patient with encephalitis commonly has an altered level of consciousness (confusion, behavioral abnormalities), or a depressed level of consciousness, ranging from mild lethargy to coma, and evidence of either focal or diffuse neurologic signs and symptoms.

Patients with encephalitis may have hallucinations, agitation, personality change, behavioral disorders, and, at times, a frankly psychotic state.

Etiology: Herpesviruses

Most commonly identified

LABORATORY DIAGNOSIS


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TREATMENT 1. Supportive 2. Acyclovir

SUBACUTE MENINGITIS


unrelenting headache

stiff neck

low-grade fever

lethargy for days to several weeks before they present for evaluation

Cranial nerve abnormalities and night sweats may be present

Cranial nerves VII and VIII are most

frequently involved. (Syphilis) ETIOLOGY

M. tuberculosis

C. neoformans

H. capsulatum

C. immitis

T. pallidum LABORATORY DIAGNOSIS TB meningitis

CSF abnormalities in tuberculous meningitis are as follows:

o elevated opening pressure o lymphocytic pleocytosis (10500 cells/

L) o elevated protein concentration in the

range of 15 g/L (10500 mg/dL) o decreased glucose concentration in the

range of 1.12.2 mmol/L (2040 mg/dL).

unrelenting headache, stiff neck, fatigue, night sweats, and fever with a CSF lymphocytic pleocytosis and a mildly decreased glucose concentration

Cryptococcal Meningitis

CSF analysis similar to TB

(+) CALAS

(+)India ink

NEUROSYPHILIS

reactive serum treponemal test [fluorescent treponemal antibody absorption test (FTA-ABS) or microhemagglutination-T. pallidum (MHA-TP)] is associated with a CSF lymphocytic or mononuclear pleocytosis and an elevated protein concentration, or when the CSF VDRL (Venereal Disease Research Laboratory) is positive.

TREATMENT

TB MENINGITIS o Initial therapy is a combination of

isoniazid (300 mg/d), rifampin (10 mg/kg per day), pyrazinamide (30 mg/kg per day in divided doses), ethambutol (1525 mg/kg per day in divided doses), and pyridoxine (50 mg/d).

o If the clinical response is good, pyrazinamide and ethambutol can be discontinued after 8 weeks and isoniazid and rifampin continued alone for the next 612 months

o Dexamethasone therapy is recommended for patients who

develop hydrocephalus.

C. neoformans o amphotericin B + flucytosine for atleast

4weeks followed by fluconazole 400mg/ day for 8 weeks

Syphilitic meningitis o PenG 3-4 million units IV q4 x10-14 days


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SUBACUTE SCLEROSING PANENCEPHALITIS (SSPE)

SSPE is a rare chronic, progressive demyelinating disease of the CNS associated with a chronic nonpermissive infection of brain tissue with measles virus.


a. Initial manifestations poor school performance

mood and personality changes. Typical signs of a CNS viral infection,

including fever and headache, do not occur.

b. As the disease progresses:

patients develop progressive intellectual deterioration, focal and/or generalized seizures, myoclonus, ataxia, and visual disturbances.

c. In the late stage of the illness, patients are unresponsive, quadriparetic, and spastic, with hyperactive tendon reflexes and extensor plantar responses.

DIAGNOSTIC STUDIES

a. MRI often normal early b. EEG

Initially show only nonspecific slowing, but with disease progression, patients develop a characteristic periodic pattern with bursts of high-voltage, sharp, slow waves every 38 s, followed by periods of attenuated ("flat") background. (Burst Suppression Pattern)

TREATMENT

No specific treatment

isoprinosine (Inosiplex, 100 mg/kg per day), alone or in combination with intrathecal or intraventricular alpha interferon, has been reported to prolong survival and produce clinical improvement in some patients but has never been subjected to a controlled clinical trial.

Special thanks to Sweet Sorority for the LPnotes Read on

Chronic meningitis and Brain Abscess na lang

Sorry kung kulang

Good luck and God bless sa finals!

CNS Infections 2014

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