Teaching Clinic - Meningitis

Question 1

What is done to rule out normal ICP?

Answer 1

• Non contrast CT brain
• Fundoscopy (as normal CT brain does not rule out increased ICP): papilledema

Question 2

LP:
*
TCC 307 (neutrophil 76%)
protein 1.87 g/L
glucose 1.1 mmol/L (blood 8.0)
Gram stain -ve
C/ST -ve
?? DDX
action?

Answer 2

Acute bacterial meningitis
Tuberculous meningitis
Other rare meningitis (parasitic infection, leptospirosis (transmitted by urine of animals near lakes))
Bacterial cerebritis (early small brain abscess not seen on CT scan)

Action: IV ceftriaxone (rocephin) + ampicillin (covers for leptospirosis) (total for 2 weeks)

Question 3

how will CSF change after bacterial meningitis mx?

Answer 3

Lymphocyte predominant after treating bacterial meningitis is ok
BBB broken down: so elevated protein is ok
Glucose should improve the fastest (if below 50% not satisfied)

Question 4

cause?
What to do next?

Answer 4

Persistent source of primary infection (e.g. pneumonia, bacterial endocarditis, mastoiditis or otitis media)
cerebritis or early small cerebral abscess
Inadequate immunity (prolonged antibiotics therapy required as for immunocompromised patient)

Consult micbio
MRI brain with gadolinium contrast
Consult cardiologist? echocardiogram
Explain condition to patient and relatives

Question 5

What to do?

Answer 5

If impaired conciousness do Hstix and ECG

non contrast CT brain due to reduced GCS

Question 6

What is seen and mx?

Answer 6

Hyperdensity in the pre-pontine cistern surrounding the pons

Hydrocephalus complicating subarachnoid hemorrhage

Consult neurosurgeon (due to intracerebral hemorrhage)
Do CT angiogram
Stenting, clipping

Question 7

Answer 7

Cortical bone necrosis
Radiation induced arteritis: ischemia to the bone and cause necrotic bone and causing easier infection

Question 8

Breakdown for result of patient 1

Answer 8

• SAH from ruptured pseudoaneurysm (dissection) of vertebrae
• RT induced arteritis and complicating osteomyelitis
• Infection spread from infected necrotic clivus complicating RT for NPC
• Infected necrotic bone –> non resolving meningitis
• Operation: infected necrotic bone: grew bacteroides (anaerobes)

Rx: vancomycin +metronidazole x 6 weeks and stents oinserted in sites of ruptured pseudoaneurysm

Question 9

Common sx of ABM

Answer 9

sx triad: head, fever, photophobia
Most commonly reported Sx and signs: Fever, neck stiffness, altered mental state (GCS <14)

Question 10

Timeline of ABM

Answer 10

Question 11

Answer 11

B:
C: staph aureus rash
D: Ecchymosis (soles of foot)
E: meningococcal rash (neisseria meningitidis)

All start antibiotics before

Thrombocytopenia, DIC, sepsis

Question 12

What meningitis?

Answer 12

Strept pneumoniae
Herpes labialis (mouth crust)

Question 13

Strept suis meningitis presentation?

Answer 13

Deafness: occupational illness (can apply for compensation)

Question 14

Answer 14

A: gram negative diplococci
B: gram negative bacilli (enterococci: e.coli, klebsiella)
C: streptococcus suis
D: drained skin lesion (gram positive diplococci)

Question 15

ddx of ABM

Answer 15

Question 16

Lab Ix in acute bacterial meningitis

Answer 16

Question 17

C/I for lumbar puncture in ABM?

Answer 17

Question 18

What antibiotics in ABM?
Duration of antibiotics in ABM?

Answer 18

3rd gen cephalosporins (cefotaxime, ceftriaxone)

Question 19

If clinical condition not improve by 48 hours after commencing appropriate antibiotics what to consider?

Answer 19

Question 20

Complications of ABM

Answer 20

Question 21

Answer 21

Hydrocephalus, consult neurosurg for ventriculoperitoneal shunt and obtain CSF fluid

Question 22

Answer 22

TB and fungal meningitis

Than had ischemic stroke (R hemiplegia and hemieglect) complication of meningitis

Question 23

Bilateral CN6 palsy cause?

Answer 23

False localizing sign caused by increased ICP

Question 24

Answer 24

basal meningies (gadolinium enhancement)
dilated ventricles
Rim enhancing tuberculous abscess (bottom left)
Thickened basal meninges (bottom right)

Circle of willis spread of infection (infective arteritis)

Question 25

Answer 25

tuberculous meningitis Spinal cord compression: paraplegia anti-TNFa causes reactivation of TB (must know) Can give isoniazid prophylaxis

Question 26

Treatment for TBM

Answer 26

2 (isoniazid (peripheral neuropathy --> give vit B6), rifampicin, ethambutol, pyrazinamide) + 9 (isoniazid + rifampicin) If HIV+ --> give dexamethasone

Question 27

Answer 27

T1W gadolinium enhancement in brain and meninges Abnormal gyral patterns ddx: leptomeningeal carcinomatosis PET CT done and found hypermetabolic lesions in lung

Question 28

Bronchoscopy and LN and/or lesion biopsy: cryptococcus neoformans on indian ink stain

Answer 28

Liposomal amphoterin B and flucytosine given for 26 days Thrombocytopenia due to flucytosine (myelosuppression)

Question 29

Answer 29

Previous stroke from cardioembolic stroke from rheumatic heart disease Abnormal gyral enhancement

Question 30

What is most common fungal meningitis? Mechanism of infection?

Answer 30

* Encapsulated yeast, worldwide distribution * In soil, bird excreta, animals, can even colonize humans * Via inhalation of small yeast forms from the environment (when immunocompromised --> can present with hilar lymphadenopathy) * Once in host, develop large polysaccharide capsules that * strongly resist phagocytosis * Most pulmonary infections are asymptomatic * Spread from lung and intrathoracic LN to circulate in blood ---> distant infection, most common to the CNS

Question 31

Cryptococcus neoformans resistance?

Answer 31

* Primarily on cell-mediated immunity * Natural killer cells (NK cells) - important in eliminating the initial infection in animal studies * Complements - important to prevent dissemination from lung to the CNS * Lymphocyte f(x) abnormal in most patients with disseminated cryptococcosis : CD4 T cells essential in preventing dissemination & recurrence after Rx

Question 32

What are predisposing factors for cryptococcus infection

Answer 32

* AIDS – HIV infection * RE malignancies – lymphoma, and other cancers * Sarcoidosis * Organ transplantation * Collagen vascular diseases * Corticosteroid therapy * DM * Renal failure/dialysis * Solid organ transplant recipients * Idiopathic CD4 lymphocytopenia * Other immunological disorders  impaired CD4 T cell f(x)

Question 33

Clinical features of cryptococcal CNS infection

Answer 33

Subacute/Chronic Meningitis OR Parenchymal syndromes Most common presentation in normal host = meningitis Others : 1. Cerebral abscesses 2. Isolated granulomatous lesion, cryptococcoma 3. Chronic --- mimick progressive dementia 4. Visual loss with raised ICP poor Px

Question 34

Cryptococcal parenchymal syndromes

Answer 34

* Diffuse granulomatous infiltrates * Solitary abscesses * Multiple microabscesses or macroabscesses * Meningeal & subarachinoid inflammation --> vessel occlusion * Vasculitis/arteritis (cryptococcus) ---> small vessel thromboses formed by hyphae or pseudohyphae, or microinfarcts in areas of vasculitis * Vessel wall invasion & SAH due to ruptured mycotic aneurysm (emboli from cryptococcal endocarditis)

Question 35

What to monitor with cryptococcal meningitis mx?

Answer 35

Reduce dose of amphotericin B and 5-flucytosine with renal impairment Toxicity of 5-flucytosine: Blood, Liver, Gastrointestinal

Question 36

What to do before stopping rx for cryptococcal meningitis?

Answer 36

Before stopping Rx – repeating LP: 1. CSF glucose normal 2. CSF protein on declining trend 3. Indian Ink stain may be +ve when CSF culture turns -ve (positive stain NOT = active disease) If CSF still grows cryptococcus, acute Rx should be continued + consider dose adjustment or addition of other antifungal agents.

Question 37

Mx for cryptococcal meningitis?

Answer 37

both amphotericin-B + flucytosine cross the blood placental barrier