Meningitis

Question 1

What is meningitis?

Answer 1

Meningitis is an inflammatory process involving the leptomeninges within the subarachnoid space (CSF)

Question 2

How can meningitis be classified?

Answer 2

Meningitis can be classified by duration and age.

Question 3

What are the 3 types of durations in meningitis?

Answer 3

Acute-pyogenic
Aseptic-viral
Chronic- TB, Syphilis, Cryptococcus

Question 4

What are the causative organisms in each age group of meningitis?

Answer 4

Neonates- Group B Strep, E. coli
Young adults- Neisseria meningitidis
Elderly- Listeria Monocytogenes (Immunocompromised as well), Streptococcus Pneumonia

Question 5

Classical symptoms of Meningitis

Answer 5

Headache
Fever
Nuchal rigidity

– Nuchal rigidity not present in children <1 y
– Fever and chills
– Photophobia
– Vomiting
– URI symptoms (viral and bacterial)
– Seizures Focal neurologic symptoms
(including focal seizures)

Question 6

Signs of meningeal irritation

Answer 6

Nuchal rigidity or discomfort on neck flexion
– Kernig sign: Passive knee extension in supine, patient elicits neck pain and hamstring resistance.
– Brudzinski sign: Passive neck or single hip flexion is accompanied by involuntary flexion of both hips.
 Papilledema
 Focal neurologic signs
– cranial nerve abnormalities III, IV, VI,VII)

Question 7

What are the normal features of CSF?

Answer 7

Appearance —Clear
Pressure —60-150mm
Cells—0-4
Proteins —15-45 mg/dl
Glucose —50-80 mg/dl
Bacteriology —Sterile

Question 8

What are the features of CSF in bacterial meningitis?

Answer 8

Appearance — Cloudy
Pressure — >180mm H2O
Cells— 100,000 cu mm
Proteins — Markedly raised
Glucose — Markedly reduced
Bacteriology — Organism+

Question 9

What are the investigations for bacterial meningitis?

Answer 9

Routine + Spinal tap (CSF analysis)

Question 10

What is the treatment for bacterial meningitis?

Answer 10

Antibiotics- 3rd generation Cephalosporins

Question 11

Microscopy of bacterial meningitis

On microscopic examination,………may fill the entire………….space or, in less severe cases, may be confined to regions adjacent to……………… In untreated meningitis,………. reveals varying numbers of the…………..

When the meningitis is………., the organisms and the…………….. may spread into the………………. (focal cerebritis), sometimes leading to the formation of……………

Later,………..&…………..

Answer 11

On microscopic examination, neutrophils may fill the entire subarachnoid space or, in less severe cases, may be confined to regions adjacent to leptomeningeal blood vessels. In untreated meningitis, Gram stain reveals varying numbers of the causative organism.

When the meningitis is fulminant, the organisms and the associated inflammatory cells may spread into the substance of the brain (focal cerebritis), sometimes leading to the formation of abscesses.

Later, fibrosis & hydrocephalous.

Question 12

What is Aseptic meningitis?

Answer 12

Aseptic meningitis is a clinical term for acute illness with meningeal signs and symptoms that is believed to be of viral origin.

Also, Less fulminant and Self limiting

Question 13

Causative viruses of Aseptic meningitis.

Answer 13

70% enterovirus
Echovirus
Coxsackievirus
Poliovirus
Varicella
HSV
HIV

Question 14

Investigations of Aseptic meningitis

Answer 14

Serology and PCR

Question 15

What are the features of CSF in viral meningitis?

Answer 15

Appearance —- Mild turbid (sediment. moving around)
Pressure — >250mm
Cells— 10-100
Proteins —- Raised
Glucose — Normal
Bacteriology — Sterile

Question 16

what is chronic meningitis?

Answer 16

Chronic meningitis — one that’s long-lasting — can be caused by slow-growing organisms such as fungi and Mycobacterium tuberculosis.

Question 17

About Tuberculous meningitis

Answer 17

Most Common pattern - diffuse meningoencephlitis
 Microscopy: macro+ lympho+ plasma cells
 Florid cases: granulomas
 Obliterative endartritis
 Organism: acid fast stain
 Intraparenchymal tuberculoma

Question 18

What are the features of CSF in tuberculous meningitis?

Answer 18

Appearance —- Turbid forms coagulum
Pressure — >300mm
Cells— 100-1000
Proteins —- Raised
Glucose — Reduced or normal
Bacteriology — Tubercle bacilli

Question 19

Rich focus presentations (tuberculous mening.)

Answer 19

Tuberculomas
Arachnoid fibrosis
Hydrocephalus

Question 20

What is the Cobweb appearance (depending on stage) of TB meningi?

Answer 20

active—- caseation
Inactive—- calcification
Healed—-fibrous

Question 21

What is the treatment of Tuberculous meningitis?

Answer 21

Isoniazid
Ethambutol
Pyrazinamide

Question 22

What is Fungal meningitis?

Answer 22

Fungal meningitis can develop after a fungal infection spreads from somewhere else in the body to the brain or spinal cord. Some causes of fungal meningitis include Cryptococcus, Histoplasma, Blastomyces, Coccidioides, and Candida.

Question 23

Fungal meningitis is also

Answer 23

less common.
 rare in healthy people.
 more found in people with an impaired immune system- AIDS

Question 24

In meningitis caused by Cryptococcus neoformans, the CSF..

Answer 24

-May have few cells but elevated protein, and the mucoid encapsulated yeasts can be visualized on India ink preparations.
-Extension into the brain follows vessels in the Virchow Robin spaces.
-As organisms proliferate, these spaces expand, giving rise to a “soap bubble”–like appearance

Question 25

With Histoplasma capsulatum, there is an…

Answer 25

-An increased risk for disease in the setting of HIV infection.
-Typically causes a basilar meningitis, with elevated CSF protein, mildly decreased glucose, and mild lymphocytic pleocytosis.
-Parenchymal lesions can occur, mostly from tracking of organisms along Virchow-Robin spaces.

Question 26

Coccidioides immitis most commonly causes…

Answer 26

-Meningitis in the setting of disseminated infection.
-Diagnosis can be made by examining the CSF for specific antibody.
-Without treatment, coccidioidal meningitis has a high fatality

Question 27

What is FUNGAL MENINGO-ENCEPHALITIS?

Answer 27

Fungal meningoencephalitis is a grave illness associated with high mortality, even with the best available antifungal treatment.

Question 28

FUNGAL MENINGO-ENCEPHALITIS causative organisms..

Answer 28

CRYPTOCOCCUS
CANDIDA
ASPERGILLIS
MUCOR
(Mostly in immunocompromised hosts)

Question 29

Examples of ACUTE FOCAL SUPPURATIVE CNS INFECTIONS

Answer 29

CEREBRAL ABSCESSES
SUBDURAL EMPYEMA
EXTRADURAL ABSCESS

Question 30

CEREBRAL ABSCESSES are most often caused by…………. that can arise by……………….., local extension from adjacent foci (…………, …………), or…………….. spread (usually from a primary site in the……….., …………., or distal bones, or after………..).

Answer 30

-Most often caused by bacterial infections that can arise by direct implantation of organisms, local extension from adjacent foci (mastoiditis, paranasal sinusitis), or hematogenous spread (usually from a primary
site in the heart, lungs, or distal bones, or after tooth extraction).

Question 31

Predisposing conditions of brain abscesses include………………., from which………….. are released that may produce………….. Then there is……………, associated with a right-to-left shunt and loss of……………..; and…………, as in……….., which provide a source of…………… that spread………………

Answer 31

Predisposing conditions include acute bacterial endocarditis, from which septic emboli are released that may produce multiple abscesses. Then there is cyanotic congenital heart disease, associated with a right-to-left shunt and loss of pulmonary filtration of organisms; and chronic pulmonary infections, as in bronchiectasis, which provide a source of microbes that spread hematogenously.

Question 32

Abscesses have………………… surrounded by a rim of……….. and ……………… Outside the…………… is a zone of………………

Answer 32

Abscesses are discrete destructive lesions with central
liquefactive necrosis surrounded by a rim of vascularized
granulation and fibrous tissue. Outside the fibrous capsule is a zone of reactive gliosis.

Question 33

Patients with brain abscesses almost invariably present with

Answer 33

-Progressive focal deficits
-General signs related to increased intracranial pressure

Question 34

In CHRONIC BACTERIAL Meningo-encephalits….

Answer 34

TB affects the brain and meninges
SYPHILIS affects the gummas in brain
LYME DISEASE (neurological manifestation-NeuroBorreliosis)

Question 35

VIRAL Meningo-encephalitis causative organisms….

Answer 35

ARBO VIRUSES (West Nile, Equines, Venez., many more)
 HSV1
 HSV2
 V/Z
 CMV
 POLIO
 RABIES
 HIV

Question 36

Progressive multifocal leukoencephalopathy (PML) is….

Answer 36

Progressive multifocal leukoencephalopathy (PML) is
caused by JC virus, a polyomavirus, which preferentially
infects oligodendrocytes, resulting in demyelination (main feature) as these cells are injured and then die.

Question 37

Bi-temporal encephalitis is…..

Answer 37

HSV until proven otherwise!!!!

Question 38

What cells are found in HIV ENCEPHALITIS?

Answer 38

PERIVASCULAR GIANT CELLS in WHITE MATTER

Question 39

SUBACUTE SCLEROSING PANENCEPHALITIS (SSPE) is very…..

Answer 39

-VERY rare since measles eradicated
-Thought to be caused by measles virus