CNS Infections

Question 1

Bacterial Meningitis Pathogens

Answer 1

Listeria (newborn, elderly, immunocompromised)

Neisseria (young adults)

Question 2

Aseptic (Viral) Meningitis Pathogens

Answer 2

Echovirus (most common)
Cocksackie
EBV
HSV-2

Associated with flu-like symptoms
Most common in summer

Question 3

Fungal Meningitis Pathogens

Answer 3

Cryptococcal (immunocompromised)

Question 4

LP pattern for bacterial meningitis

Answer 4

WBC > 0.5

Glucose 40

Question 5

LP pattern for aseptic meningitis

Answer 5

WBC > 0.5
40 > Glucose > 70
Protein slightly > 40

Question 6

LP pattern for fungal meningitis

Answer 6

WBC 40

Question 7

Diagnosis & treatment of bacterial meningitis

Answer 7

Dx: CSF gram stain
Tx: Ceftriaxone
Ppx: Rifampin

Question 8

Diagnosis & treatment of aseptic meningitis

Answer 8

Dx: Serology
Tx: Supportive

Question 9

Diagnosis of fungal meningitis

Answer 9

Dx: Increased opening pressure

India ink stain on CSF

Question 10

Meningitis clinical picture

Answer 10

Fever
Headache
Nuchal rigidity
Photophobia
Kernig's sign (supine w/flexed hip, knee extension leads to pain)
Vomiting

Question 11

Diagnosis of meningitis in general

Answer 11

Lumbar puncture

Low glucose with high protein = bacterial
Normal glucose with slightly high protein = viral
Low glucose with slightly high protein = fungal

Question 12

Typical Viral Enecphalitis Symptoms & Signs

Answer 12

Fever
Headache
Focal neurologic defecits
Altered mental status

Question 13

HSV Encephalitis Symptoms & Signs

Answer 13

Fever
Headache
Focal neurologic deficits (AMS, CN deficits, ataxia, hyperreflexia, focal seizures
Behavioral symptoms (eg hypomania, Kluver-Bucy syndrome)
Amnesia

Question 14

Kluver-Bucy Syndrome

Answer 14

Hyperphagia
Hypersexuality

Occurs with HSV encephalitis

Question 15

Viral Encephalitis CSF Findings

Answer 15

WBC moderately > 0.5

Protein > 40

Question 16

HSV Encephalitis CSF Findings

Answer 16

WBC > 0.5 (predominantly Lymphs)
RBC Increased
2/2 Hemorrhagic destruction of temporal lobes
Protein > 40

Question 17

HSV Encephalitis Diagnosis

Answer 17

MRI shows temporal lobe lesions
EEG shows focal high amplitude slow waves
PCR of HSV in CSF (GOLD STANDARD)

Question 18

HSV Encephalitis Treatment

Answer 18

IV Acyclovir

Question 19

Cerebral Toxoplasmosis Diagnosis

Answer 19

MULTIPLE ring-enhancing spherical lesions
in Basal Ganglia & gray-white junction on MRI

Note: +serology is commmon in US and is not specific

Question 20

Intraparenchymal Brain Abscess Pathophys

Answer 20

Direct spread (eg sinusitis, mastoiditis, OM)
Strep viridans or anaerobes

Hematogenous spread (eg Endocarditis or Osteomyelitis)
Staph aureus or gram-neg

Penetrating trauma or neurosurgery
Staph aureus

Question 21

Intraparenchymal Brain Abscess Clinical Presentation

Answer 21

Fever (only present in 50% of cases)
Headache
Focal neurologic defecits
AMS
Seizures

Question 22

Intraparenchymal Brain Abscess Diagnosis

Answer 22

Head CT ring-enhancing lesion

Question 23

Intraparenchymal Brain Abscess Treatment

Answer 23

Prolonged Antibiotic Therapy (4 - 8w)

+/- Surgical Drainage or aspiration

Question 24

Intraparenchymal Brain Abscess Complications

Answer 24

Cerebral Edema

Herniation

Question 25

Spinal Epidural Abscess Risk factors

Answer 25

IV Drug Use
Immunocompromise
Sources of local spread (surgery, osteo, epidural inj)
Distant infection (hematogenous spread)

Question 26

Spinal Epidural Abscess Pathogen

Answer 26

Staph Aureus

Question 27

Spinal Epidural Abscess Clinical Presentation

Answer 27

Fever
Sever focal back pain
Neurologic deficits (eg radiculopathy, motor & sensory, bladder or bowel dysfunction)

Question 28

Spinal Epidural Abscess Diagnosis

Answer 28

CBC
ESR
CRP
BCx
MRI of spine w/contrast --> CT-guided biopsy (to ID pathogen)

Question 29

Spinal Epidural Abscess Treatment

Answer 29

Empiric Antibiotics

+/- Surgical decompression within 24 hours (to prevent Spinal Cord Compression & Cauda Equina Syndrome)