CNS Flashcards
(195 cards)
1
Q
Bacterial causes of meningitis
Infants (2-4 mnths)
A
S. agalactiae,
E. coli,
L. monocytogenes,
S. pneumoniae,
N. meningitides,
H. influenzae
Pressing a PIN on a baby will give a MEAN cry
Pneumonae, INfluenza
Monocytogenes,Ecoli, aglactia, Nisseria meningitis
1
Q
Viral meningitis also reffered to as
A
Aspectic meningitis
1
Q
Venezuelan Equine Encephalitis Virus- type
A
Alphavirus
1
Q
Non-polio Enteroviruses common types
A
Enterovirus 71, Echovirus 18, Coxsackieviruses
2
Q
Infants (2-4 mnths) Bacterial meningitis
A
S. agalactiae, E. coli, L. monocytogenes, S. pneumoniae, N. meningitides, H. influenzae*
2
Q
Post splenectomy, complement deficiency
A
N. meningitides
2
Q
This bacterial meningitis seen in
Infants -
– Adults >60y, alcoholics, cancer patients, renal transplant.
A
Listeria monocytogenes
2
Q
Encephalitis CSF findings
A
3
Q
Rabies virus dx
A
– Skin biopsy: Immunohistochemical staining - Rabies Ag
– Negri bodies: Intracytoplamsic inclusions in neurons
– Corneal smears – Rabies Ag
– Rabies virus neutralizing Ab – CSF or serum (unimmunized) Direct Ab Test
3
Q
African Sleeping Sickness
Protazoa
A
African Trypanosomes
4
Q
Vectors st. Louise vs. eastern equine
A
4
Q
Schistosomiasis
A
Schistosoma species
Liver or bladder
brain or spinal cord vasculature
5
Q
Haemophilus influenzae
• Clinical features
A
Slower onset (meningococcal meningitis), 3-4d – Follows: nasopharyngitis, sinusitis or otitis media – 1/3 survivors – neurologic sequelae
5
Q
Predominant Demyelination imaging defect
A
JC virus
6
Q
Most common cause (Chronic meningitis)
A
Mycobacterium tuberculosis
6
Q
CSF findings in Western Equine Encephalitis Virus
A
CSF: pleocytosis (lymphocytic), normal-↑ protein, normal glucose
6
Q
Primary amebic memeningoencephalitis (PAM)
Ameoba implicated
A
Naegleria fowleri
7
Q
Underlying conditions related to Staphylococci
A
Diabetes mellitus
– Alcoholism
– Chronic renal failure (hemodialysis)
7
Q
Dx of California Encephalitis Group
A
– IgM antibodies in CSF or serum
8
Q
Listeria monocytogenes serotypes
A
Serotypes: 1/2b & 4b (80% cases)
8
Q
St. Louis Encephalitis Virus distribution
A
Canada, US, Central & Southern America
8
Q
GAE; skin or lung lesions
Amoeba implicated
A
Balamuthia mandrillaris
8
Q
Eosinophilic Meningitis
A
Angiostrongylus cantonensis (rat lung worm)
Gnathostoma spinigerum
9
Q
Clinical features of Streptococcus pneumoniae
A
Rapid 1-2 days (or gradual)
– Impaired consciousness common
9
Subependymal enhancement imaging defect
CMV ventriculitis
10
Meningitis
inflammation of meninges
11
Vector-borne viruses
Togaviridae
– Flaviviridae
– Bunyaviridae
– Reoviridae
12
Multifocal haemorrhagic infarctions & demyelinating lesions imaging defect
Varicella zoster virus vasculopathy
13
Basilar skull fracture + CSF leak
Puts you at risk for this bacterial meningitis
Streptococcus pneumoniae
13
Diagnosis neoforms
india ink (capsule)
14
CM1 defects (Hodgkin’s disease, steroid therapy), elderly
L. monocytogenes
14
Distribution of Venezuelan Equine Encephalitis Virus
Southern US, Central & S. America
15
Herpes simplex 1 & 2 connection to meningitis
Post neonatal
• Important: differentiate encephalitis from meningitis
– Most common: HSV 2 • primary to genital infection
• 36% women, 13% men
16
Bacterial meningitis Neonates (0-2 mnths)
Group B Streptococci (S. agalactiae), E. coli (other Gram –ve enterics), L. monocytogenes
16
Spirocheteal meningitis... whats the bacterial cause
Treponema pallidum
17
Slow onset (period of weeks) – ↓ Fever, lethargy – TB, Fungi & (Protozoa)
Chronic (RARE)
18
Brudzinski’s sign
Look up pic Flex knees and neck
18
Sx of California Encephalitis Group
Focalneurologicdisease
– Hemiparesis, aphasia, dysarthria, chorea
19
Biology behind prions
– Normal cellular glycoprotein: PrPc (↑ a helix, ↓ b helix)
– Infectious glycoprotein form: PrPsc (↓a helix, ↑ b helix)
21
Adults (Adolescents- \>55y) Bacterial meningitis
N. meningitides, S. pneumoniae
22
Fontal, Temporal, Parietal, abscess
Predisposing/ bacteria
Trauma, Penetrating wound
S. aureus, Clostridia
23
Bacterial etiology of CSF shunts
– Staphylococci (epidermidis & aureus)
– Gram negative bacteria (E. coli, Klebsiella, Proteus & Pseudomonas)
– Streptococci
– Diphtheroids (Propionibacterium acnes)
– Anaerobes
– Mixed culture
24
Temporal lobe abcess what predisposes you, what bacteria
Otitis media, Mastoiditis
Streptococci, Bacteroides, Enterobacteriacea
26
HA-CNS infection: MRSA
* CSF shunts: S. epidermidis
* Mortality 14-77%
Staphylococci
26
Mycobacterium tuberculosis adult vs children
– Children (haematogenous disseminated tuberculosis) • Rapid
– Adults
• Indolent
27
Eastern Equine Encephalitis Virus distribution
US, Southern America, Caribbean
27
FOCAL CNS SYNDROMES
Brain Abscess
Subdural empyema
Epidural abscess
28
CSF findings in Colorado Tick Fever Virus
CSF: pleocytosis (mildly lymphocytic), normal-mildly↑ protein, normal glucose
29
Enterovirus Seasonality
Late Summer, fall
30
Yellow csf
Blood breakdown products Hyperbilirubinemia CSF protein ≥150mg/dL (1.5g/L), \>100,000 RBC/mm3
30
St. Louis Encephalitis Virus- type
Flavivirus
31
Listeria monocytogenes
• Biology:
Gram +ve rod – Virulence:
• Internalin A & B • Listeriolysin O
31
PRIONS
Infectious proteins
– No Nucleic acid genome
– Resistant: formaldehyde (3.7%), dry heat, boiling, ethanol (50%) & ionizing radiation
– Sensitive: phenol (90%), household bleach, ether, NaOH (2 N), strong detergents (10% sodium dodecyl sulfate) & autoclaving (1 hour, 121oC)
32
Alcoholism, skull fractures, myeloma, splenectomy
S. pneumoniae
32
Clinical feature of Mycobacterium tuberculosis
Rupture in subarachnoid space
33
Distribution of Japanese Encephalitis Virus
Asia, Western Pacific, Australia
34
Dx of fungal brain abscess
CT scan
– Hypodense centre
– Peripheral uniform ring – Brain oedema
35
Fungal Meningitis lab values
Opening pressure Variable WBC count Variable Cell differential lymphocytes Protein 50-100mg/dL Glucose
35
Comparing meningitis lab values by organism
35
Japanese Encephalitis Virus type
Flaviviridae
36
\>50 years Bacterial meningitis
S. pneumoniae, N. meningitides, L. monocytogenes, Aerobic Gram –ves
36
Eastern Equine Encephalitis Virus- type
Alphavirus
37
Granulomatous Amebic Encephalitis (GAE); skin or lung lesions; amebic keratitis
Ameoba implicated
Acanthamoeba species
38
Western Equine Encephalitis Virus- type
Alphavirus
39
Pathogenesis of CNS shunts
– Retrograde infection
– Skin
– Haematogenous seeding
– Colonization at surgery
41
Neisseria meningitidis
• Clinical features
Distinguishing feature
Quick onset
– Acute photophobia
– Skin petechiae → ecchymoses/diffuse petechial rash -
DIC
42
Neisseria meningitidis
• Prevention
2005, Quadrivalent: A, C, Y & W135
– Protection: ~3y
– No protection from carriage (MPSV4-menomune)
meningococcal conjugate vaccine seen as better
43
CSF findings in Measles
CSF: usually normal (↑Ig level)
44
Exposure to bats, other wild animals, dog bites, developing countries
Rabies
46
Brown CSF
Meningeal melanomatosis (Metastatic Melanoma)
47
characteristics of Enteroviruses
Picornaviridae
– Naked, icosahedral, small (25-30nm), ss +ve RNA
Echoviruses 30, 18, 16, 11, 9, 6 & 7
• Coxsackieviruses B1, B2, B3, B4 & A9 • Enteroviruses 71 & 70
48
Meningoencephalomyelitis
infection of meninges+ brain parenchyma+spinal cord
49
Colorado Tick Fever Virus dx
IgM by ELISA
50
Histoplasma capsulatum
• Geographic location
Ohio & Mississippi river valley, Central America
52
Distribution of Colorado Tick Fever Virus
WesternUS&Canada(Mountains)
53
NORMAL CSF VALUES
• WBC count: children & adults 0-5/mm3 (70% lymphocytes, 30% monocytes) neonates 32/mm3 • RBC count: None • [Glucose]: ratio to serum glucose ≥60% 40-70mg/dL not \>300mg/dL • [Protein]: adults 18-58mg/dL (by 6-12 mnths old) newborn 150mg/dL
54
Brain abscess in the frontal lobe- what predisposes, and what organisms
Sinusitis, Dental abscess
Streptococci, Bacteroides, S. aureus, Haemophilus spp.
55
Abscess
localised infection in spinal cord or brain – Acute/Chronic Brain Abscess – Empyema – epidural or subepidural abscess
55
Lymphocytic choriomeningitis virus
Rare
– Contact with rodents & excreta (hamsters, rats, mice)
• Lab workers, pet owners, unhygienic housing conditions
57
Encephalitis –
inflammation of the brain parenchyma
58
Herpes viruses implicated in meningitis
HSV, VZV, CMV, EB virus & HHV -6, 7, 8
60
Most common fungal cause of meningitis
Cryptococcus neoformans (Cryptococcus gattii)
62
Rickettsia (RMSF) Seasonality
Late Summer & Spring
63
Herpesviruses Clinical features
Incubation period uncertain • Rapid onset – several days
– Fever (90-100%)
– Altered consciousness (97-100%) – Headache (70-81%)
64
CSF findings in California Encephalitis Group
CSF: pleocytosis (lymphocytic), ↑ protein, normal glucose
65
THis bacteria Uncommon, seen in Early postneurosurgical/post-trauma
Staphylococci
66
Eastern Equine Encephalitis Virus CSF/MRI findings
CSF: pleocytosis (neutrophil predominance (2/3)), ↑ protein, norm glucose, RBC’s common
– MRI: thalamus, basal ganglia, brain stem
67
THis bacteria
## Footnote
Group B Strep
• Most common: neonates (52% cases, US) • Mortalityrate:7-27%
Streptococcus agalactiae
69
Who is most at risk for encephalitis when infected with st. louise
\>60
71
Blastomyces mostly presents with
Brain abscess
72
Temporal lobe & limbic imaging problem
HSV & HHV-6 encephalitis
72
Difference between Subdural empyema and epidural abcess
Epidural abcess- MRI pachymeningeal enhancement, superficial area of diminished intensity
73
Pink CSF
Blood breakdown products
73
Haemophilus influenzae
• Human carriage
80% children, 20-50% adults (URT) – Unencapsulated
73
Coccidioides dx
Eosinophils (CSF) Wright-Giemsa Stain
– Complement fixation test
74
sub acute sclerosing panencephalitis seen in
Measles
75
Western Equine Encephalitis Virus dx
WEE IgM antibodies in CSF or serum
77
CSF/MRI findings in Japanese Encephalitis Virus
CSF: pleocytosis (lymphocytic), mildly↑ protein, normal glucose
– MRI: normal
78
California Encephalitis Group- type
Bunyaviridae
80
Green CSF
Hyperbilirubinemia Purulent CSF
80
Colorado Tick Fever Virus type
Reoviridae
82
Rare cases protazoa affecting CNS
Free-living ameba
84
Streptococcus pneumoniae characteristics
Non-motile, Gram +ve diplococci – Virulence:
• Capsule
– (18 serogroups, 82% pneumonia = meningitis)
* IgA protease
* Pneumolysin (cytotoxin)
85
Tubercular Meningitis lab values
Opening pressure Variable WBC count Variable Cell differential Mostly lymphocytes (10–500 cells/ml) Protein 10-500mg/dL Glucose 20-40mg/dL
86
Enteroviruses epidemiology
85-95% all cases
• Age: Infants & Young children
– no previous exposure & immunity
* Adults(common)
* Geographic consideration - Worldwide distribution
* Seasonal consideration:
– Temperate climate: summer/fall (water) – Tropical: year round (faecal-oral)
88
Associated with congenital defects and AIDS
Protazoa affecting CNS
Toxoplasma gondii
89
Bacterial Meningitis Lab values
Opening pressure Elevated WBC count ≥1,000/mm3 Cell differential Neutrophils 90% (\>100cells/ml) Protein 100-500 mg/dL Glucose 0-10mg/dL
90
US: Most common epidemic
West Nile Virus
92
Rabies tx
– Postexposure prophylaxis
– Wash wounds: soap & water + providone-iodine
– Vaccine
– Human rabies immunoglobulin (HRIG)
93
• Direct spread CNS
Trauma or injury
– Most common: Staphylococcus aureus
– Immunodeficient/HIV: Nocardia, Aspergillus, Candida
94
Orange CSF
Blood breakdown products Xanthochromia
95
Treponema pallidum known to cause
Clinical neurosyphilis
Syphilitic meningitis (0.3-2.4% untreated cases) – Meningovascular syphilis
– Parenchymatous neurosyphilis
– Gummatous neurosyphilis (rare)
96
CSF findings in Venezuelan Equine Encephalitis Virus
pleocytosis (lymphocytic), ↑ protein, normal-↑ glucose
97
Etiology of subdural empyema
– Streptococci (25-45%)
– Staphylococci (10-15%)
– Enterobacteriacea (3-10%) – Anaerobic bacteria (33%) – Polymicrobial
99
Candida found in
– Neonatal ICU (use of IV catheters)
Postneurosurgery
– Immunosuppressed
100
Haemophilus influenzae
• Biology characteristics
Non-motile, Gram –ve rods – Fastidious
* NADP (V) & Haematin (X), (Chocolate agar) – Virulence:
* Capsule (polyribitol phosphate) • Pili
* LPS
102
Types of Facultative anerobe bacteria
Klebsiella, E. coli, S. marcescens, P. aeruginosa
Neontates: E. coli K1
Pregnant women carry this in their rectum
103
West Nile Virus dx
ELISA
104
Cysticercosis
Taenia solium (pork tape worm)
Muscle and brain
106
West nile sx
60 years of age) – Brain parenchymal involvement
– CSF: pleocytosis, ↑ protein, normal glucose
– MRI: thalamus, basal ganglia, brain stem
• Poliomyelitis-like (acute flaccid paralysis)
– Motor neuron injury (anterior horn of spinal cord) – Brain parenchymal involvement
108
Most common: sporadic encephalitis
Herpesviruses
109
Routes of infections CNS
Direct Heamatogenous Neural tissue
111
Arboviruses (Arthropod-borne)
– Mainly encephalitis
113
Cerebral Malaria
Protazoa
Plasmodium falciparum
114
St. Louis Encephalitis Virus findings in csf/ mri
CSF: pleocytosis, ↑ protein, normal glucose
– MRI: normal, or substantia nigra
115
Neural tissue (rare)
Human Herpesvirus 1-3 – Rabies: peripheral→nerve axons→ganglia & spinal cord→brain
117
PRevention of polio
– 3 strains of Polio (1, 2 & 3)
– 4 Vaccines available
– Inactivated Polio Vaccine (IPV) - Salk
– Live Oral Polio Vaccine (OPV) - Sabin • Monovalent (mOPV1 & mOPV3)
• Bivalent (bOPV)
119
Most higher cortical function deficits.
• Progress over weeks-months: profound dementia (memory loss, impaired judgment, intellectual function
Creutzfeldt-Jakob disease
120
Immunocompromised (allogenic bone marrow transplants) herpes type
HSV 6
122
Pathogenesis of rabies
123
Multiple lobes brain abscess what predisposes you and organisms
Infective endocarditis, Congenital Heart Disease, Lung abscess
S. aureus, Streptococci (viridans), Fusibacteria, Nocardia
125
TESTS FOR MENINGISM
Inability to flex neck (chin to chest) • Inability to oppose nose with knee • Tripod sign: Inability to sit up without using hands • Kernig’s sign • Brudzinski’s sign
126
Head trauma/neurosurgery put you at risk for these bacterial meningitis
Facultative anerobe bacteria
128
St. Louis Encephalitis Virus dx
Anti-SLEV IgM antibodies in serum or CSF
129
What is the human carriage of strep pneumonia
throat & nasopharynx
130
Primary amoeba affecting CNS
Entamoeba histolytica
131
CSF normal pressure
Normal pressure: 70-180 mm H2O
132
Dx of Venezuelan Equine Encephalitis Virus
VEE IgM antibodies in CSF or serum
133
Bacterial causes of meningitis
Neonates (0-2 mnths)
Group B Streptococci (S. agalactiae),
E. coli (other Gram –ve enterics),
L. monocytogenes
ALE
134
Bacterial meningitis can be seen in Lyme
disease whats the bacteria
Borrelia burgdorferi
135
Polio virus transmission
Faecal-oral
136
Dx of Japanese Encephalitis Virus
– IgM antibodies in CSF by ELISA
– PCR
138
Eastern Equine Encephalitis Virus dx
EEE IgM antibodies in CSF by ELISA
139
CSF shunts
S. aureus
140
Bacterial causes of meningitis
## Footnote
Adults (Adolescents - \>55y)
N. meningitides,
S. pneumoniae
141
Human carriage (5-30% healthy individuals, URT)
Neisseria meningitidis
Higher in military recruit camps, schools
142
Immunocompetent adults herpes type
HSV 1
143
Onset: hours-several days • Life-threatening • Meningism: Fever, Headache, Nuchal rigidity, Nausea & Vomiting, Photophobia • Altered mental status
Acute
144
ENCEPHALITIS
Inflammation of the brain parenchyma
145
Haematogenous dissemination cns
Respiratory tract infection: N. meningitidis – Insect bite: West Nile Virus – Transplacental: Rubella
146
Listeria monocytogenes
• Clinical features:
Subclinical-gastrointestinal like
– Neonatal
– Immunocompromised
147
Routine Tests for CSF
WBC count with differential RBC count [Glucose] [Protein] Gram stain/ India stain Bacterial culture/ Fungal culture
148
Neisseria meningitidis
• Biology characteristics
– Non-motile, Gram -ve diplococci
(kidney-bean shaped) – Fastidious
* 5-10% CO2, (Chocolate agar, Modified Martin-Thayer agar) – Virulence:
* Capsule (serogroups A, B, C, X, Y & W-135) • IgA protease
* Pili
* LOS
149
Increased Risk Factors csf shunt infections
– Premature birth
– Previous shunt infection
– Cause of hydrocephalus
– Length of the shunt procedure
– Shunt revision
150
Bacterial causes of meningitis
\>50 years
S. pneumoniae,
N. meningitides,
L. monocytogenes,
Falcultative anerobes
152
Polio endemic
Endemic: Afghanistan, Pakistan, & Nigeria (Somalia, Ethiopia, Kenya, South Sudan & Cameroon)
153
Haemophilus influenzae
why has its rates dropped compared to previous years
Present: 7% cases (conjugate Hib vaccine @ 2 mnths/age)
155
MRI Fungal abscess in brain
Interhemispheric fissure
156
Alcoholism, post splenectomy, hypogammaglobulinemia
H. influenzae
157
This bacteria 15-35%
asymptomatic pregnant women
Streptococcus agalactiae
158
Myelitis
infection of spinal cord
159
Tick bite
Lyme disease
161
Fungal causes CHRONIC MENINGITIS
Cryptococcus
Histoplasma
162
California Encephalitis Group distribution
CEV, La Crosse & Jamestown – US; Tahyna - Russia
La Crosse: Mississippi & Ohio river basins
164
DIAGNOSTIC TESTS for encephalitis
Neuroimaging
– All patients MRI
– Distinctive patterns of abnormalities
165
Western Equine Encephalitis Virus distribution
Western US, Western Canada, S. America
166
Bacterial meningitis Most common: children & young adults
Neisseria meningitidis
168
Polio clinical features
– Inapparent-mild 90% cases
– Non-paralytic: Meningitis 8% cases (self-limiting)
– Paralytic disease 1% cases
– Polio encephalitis: Rare
– Incubation 1-2 wks
– Infection & death anterior horn cells (grey matter)
169
CDC PEP Recommendations of rabies
– Wash all wounds with soap and water
– 1 dose of HRIG & 4 doses of vaccine (Days 1, 3, 7 & 14 + 2 boosters on Day 0 and 3)
170
Bacterial causes of meningitis
4-6 mnths
N. meningitides,
S. pneumoniae,
H. influenzae
171
OVerv view of sx for viral meningitis
Usually acute benign, self-limiting, monophasic
– Symptoms: cranial neuropathy & raised intracranial pressure uncommon
172
Histoplasma capsulatum seen in
Immunosuppressed
– AIDS
– Solid organ transplants
173
Monkey handlers or monkey bite
Herpes B encephalitis
174
West Nile Virus- what type of virus
Flavivirus
175
Most frequently observed cause of bacterial meningitis (61% total cases, US)
Streptococcus pneumoniae
176
Lymphocytic choriomeningitis Seasonality
Winter
177
Coccidioides spp
• Geographic location
Central & Southern Arizona + Central Valley of California
178
4-6 mnths Bacterial meningitis
N. meningitides, S. pneumoniae, H. influenzae\*
179
– Increased lymphocytes – Self limiting – Viral or non infectious (Absence of cultivable bacteria or fungi)
Aseptic (acute)
180
Kernig’s sign
Look up pic Elevate legs
181
Cryptococcus neoformans seen in
Immunosupressed & previously infected healthy
182
Overcrowding
Meningococcal meningitis
183
Rabies virus type
Rhabdoviridae
184
Transmission of prion dz
– Sporadic: CJD (85% cases), 50-75 year olds
– Inherited: GSS, FFI (10-15%)
– Ingested: Kuru (mostly disappeared)
– Iatrogenic: corneal transplants, contaminated EEG implants, possibly contaminated human growth factor
185
AIDS, other CM1 defects
C. neoformans
186
Hydatid Disease
Echinococcus species
Liver (75%) and lungs (15%) brain parenchyma
187
Paragonimiasis
Paragonimus
Lungs
188
Coccidioides spp seen in
CA-pneumonia,
Immunosuppressed individuals (AIDS)
189
Dx of polio
– CSF: PMN early→lymphocytes, ↑protein, normal
glucose
– CSF: RT-PCR
190
• Most common VIRAL CAUSES of meningitis
: Enteroviruses
191
Haemophilus influenzae Prevention:
Vaccine: Hiberix
Uncapsulated are becoming a problem... can not use current drugs against them
192
Histoplasma capsulatum Dx
– Histoplasma antigen
(CSF) – Cultures -ve
193
Rare invasion of the brain
Protazoa implicated
Entamoeba histolytica
194
Nipah Virus encephalitis
Malaysia
195
Eastern equine virus transmission cycle
