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Flashcards in CNS infection Deck (39):
1

what is meningitis? aseptic meningitis? encephalitis? meningoencephalitis?

Meningitis = Infection of the meninges
•Aseptic meningitis = meningitic symptoms plus white cells in CSF, but no growth on routine cultures
•Encephalitis = Inflammatory process of the brain (usually acute and diffuse, often viral, altered mental status early, focal signs)
•Meningoencephalitis = combination of meningeal and parenchymal disease)

2

encephalitis symptoms?

seizures, focal signs, altered mentation reduced GCS

3

history and examination?

Fever, headache, photophobia, neck stiffness
•Rash, sore throat, swollen glands, vomiting, genitourinary symptoms
•Illness in contacts
•Sexual history
•Travel abroad
•HIV risk factors
•Immunisation history
•Exposure to rodents / ticks

4

three signs of meningism?

nuchal rigidity - Nuchal rigidity is the inability to flex the neck forward due to rigidity of the neck muscles; if flexion of the neck is painful but full range of motion is present, nuchal rigidity is absent.[citation needed]

 

Kernig's sign - Kernig's sign (after Waldemar Kernig (1840–1917), a Baltic German neurologist) is positive when the thigh is bent at the hip and knee at 90 degree angles, and subsequent extension in the knee is painful (leading to resistance).[3] This may indicate subarachnoid hemorrhage or meningitis.[4] Patients may also show opisthotonus—spasm of the whole body that leads to legs and head being bent back and body bowed backwards.[citation needed]

Brudzinski's sign - Jozef Brudzinski (1874–1917), a Polish pediatrician, is credited with several signs in meningitis. The most commonly used sign (Brudzinski's neck sign) is the appearance of involuntary lifting of the legs when lifting a patient's head off the examining couch, with the patient lying supine.[2][5]

Other signs attributed to Brudzinski:[6]
The symphyseal sign, in which pressure on the pubic symphysis leads to abduction of the leg and reflexive hip and knee flexion.[7]
The cheek sign, in which pressure on the cheek below the zygoma leads to rising and flexion in the forearm.[7]
Brudzinski's reflex, in which passive flexion of one knee into the abdomen leads to involuntary flexion in the opposite leg, and stretching of a limb that was flexed leads to contralateral extension.[8]

5

CSF?

Clear / colourless
•Sterile
•Glucose 60-70% of blood glucose
•Protein 0.15-0.5g/l
•White cells <5 / mm3
•Red cells <1 / mm3

6

papilloedema?

veinsengorged run downhjill to retinal surface

 

blurry indistint margin

 

Feathery kane shaped hemorrhage in nerve fiber layer

7

viral meningitis?

Enteroviruses (46%) now most common because of MMR
•HSV type 2 (31%)
•Varicella zoster virus
•HSV type 1
•Often no cause identified

8

Enteroviruses>

Coxsackie A & B, echoviruses, polioviruses, enterovirus 71
•Systemic infection; neuroinvasion
•Check viral PCR

9

HSV type 2?

Second most common cause
•Esp. young adults
•In genital HSV-2 meningeal symptoms in:
36% women
13% men
But frequently unrelated to genital herpes

10

infections and cells involved
?

A image thumb
11

Bacterial meningitis?

1. Pneumococcal (streptococcus pneumoniae): esp. elderly, immunocompromised, alcoholics, smokers, diabetics
2.Meningococcal (neisseria meningitides): children & young adults; epidemics
3.Listeria monocytogenes: neonates; defective cell-mediated immunity

12

Treatment of pneumococcal/meningococca meningitis?

Benzylpenicillin IV / IM (if no access)
•Adults and children >10 y: 1.2g
•1-9 y: 600mg
•Under 1 year: 300mg

13

empirical antimicrobial therapy?

N meningitides
•S pneumoniae
•L monocytogenes
•Vancomycin 15mg/kg every 8h +/- ceftriaxone 2g bd or cefotaxime 2g qds
•ampicillin

14

sensitivity of s.pneumonia, menigitidis, ad l. monocytogenes?

S. pneumoniae, H influenzae, gp B strep – 10 days of antibiotics
•N. meningitidis – 7 days of antibiotics (plus: Rifampicin 600mg orally every 12 h for 2 days to eradicate nasal carriage)
•L monoctogenes / enterobacteriacaea – 3-4 weeks

15

dexamethasone?

Helpful in pneumococcal
•NOT all types and NOT for postsurgical meningitis or severe immunocompromise

16

systemic compication?

Hypotension (septic shock) = poor prognosis……ITU
2.Hyponatraemia <135 esp. L monocytogenes
3.Hypernatraemia >143 = poor prognosis…more severe disease, seizures, coma
4.Arthritis..from blood or immune complexes…abrupt onset of single hot, swollen, painful joint

17

viral encephalitis?

HSV (15% of all cases)
•Mumps
•Enteroviruses
•Arboviruses (arthropod borne viruses)
•Measles
•Rabies
•EBV
•CMV

18

herpes simplx virus?

Reactivation of dormant HSV-1 in trigeminal ganglion / olfactory bulb
•Viral spread to brain via sensory pathway
•Fatal in 40% untreated cases
•Fever, confusion, headaches and seizures

19

diagnosis of hsv encephalitis?

1Compatible clinical history of encephalitis
2CSF analysis and PCR
1MRI brain
2EEG

20

what does PLED stand for?

Periodic lateralised epileptiform discharges (PLEDs)

 

PLEDs are an electroencephalographic phenomenon consisting of high voltage stereotyped periodic transients distributed over one hemisphere, associated with acute or subacute structural lesions as well as with metabolic abnormalities

21

HSV treatment?

Acyclovir 10 mg/kg IV every 8 hours for 14 - 21 days
•Start ASAP - fatality reduced by 50%
•May need anticonvulsants e.g. phenytoin
•ICP monitoring of comatose patients
•Ensure adequate hydration and monitor renal function

22

abscess?

Usually streptococcal
•Surgical: staphylococcal
•Antibiotics: penicillin
metronidazole
chloramphenicol / cefotaxime
•2-3 weeks IV then 3-4 weeks oral
•Surgical drainage / excision

23

CT LP CT of HIv infection?

•Cryptococcus
•Tuberculosis
•Lymphoma
•PML
•CMV
•Toxoplasmosis

24

cryptococcus neoformans?

Acquired by inhalation
•CD4+ < 50
•Acute or latent reactivation ?
•Meningitis / encephalitis

25

CSF diagnosis of cryptococcus?

Organisms in CSF
•India ink stain

26

treat cryptococcus?

2 weeks of:
IV Amphotericin B
&
Flucytosine
Fluconazole (8 weeks)

27

TB-meningitis?

Headache, fever, neck stiffness, +/- coma, cranial nerve palsies

28

TB mengitisi causes?

adhesion formation

obliteative vasculitis

encephalitis

tuberculoma

29

TB stainig?

Ziehl-Neelson stain
•Culture of TB (3-6/52)
•PCR (c.f. ZN stain and specificity variable)

30

TB treamtnet?

intensive

1.Rifampicin
2.Isoniazid
3.Pyrazinamide
4.Ethambutol OR Streptomycin

Continuation

1.Rifampicin
2.Isoniazid

31

steroids?

Dexamethasone 0.3 - 0.4 mg/kg
•Taper over 6-8 weeks
•23% reduction in mortality

32

primary cns lymphoma?

Non-Hodgkin’s B cell
•Related to EBV
•EBV transforms B cells
•Focal lesions
•CD4+ <50
•Meningitis in 25%
•Aggressive course

33

treatment for primary cns lymphoma?

Radiotherapy improves symptoms in 50-70%
•Median survival <3/12
•HAART treatment prolongs survival

34

PML

progresive multifocal leucoencephalopathy

 

JC virus acquired childhood / young adult (70-90%)
•Latent in kidney, lymphoid tissue, CNS
•Multifocal deficits
•Progressive dementia
•Coma
•Death within 1-6 months
•Fever and headache usually absent
•PCR JC virus in CSF

35

CMV encephalitis?

Common childhood
•Reactivation
•CD4+ <50
•Tx: Antivirals (HAART /Ganciclovir/ Foscarnet/ Cidfovir)

 

Encephalitis with dementia
2.Ventriculoencephalitis:delirium, cranial neuropathy, nystagmus, ataxia

36

toxoplasmosis from?

rodent eate by cat,makes unsporulated oocyst in feces, this then goes in litter or food and we inhale o eat sporulated oocyst.

37

brina piospy for toxoplasmosis?

A image thumb
38

conditions toxoplasmosis can cause?

toxoplasma choreioretinitis

cerebral toxoplasmosis - features , Headaches

•Fever
•Confusion
•Lethargy
•Hemiparesis
•Ataxia
•Cranial nerve palsies

 

diagnosis 

+ Headaches, fever, focal signs etc.
+
Anti-toxoplasma antibodies
+
CD4 count < 200
= CEREBRAL TOXOPLASMOSIS

 

treatment

Pyrimethamine & sulphadiazine

 

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