Exam 4 Encephalitis/CNS Abscess

Question 1

Meningitis vs Encephalitis, primary difference?

Answer 1

Normal or abnormal brain fxn:

Menin = Normal fxn; have fever, HA, etc

Enceph = Altered mental state (AMS), seizures, motor/sensory deficits

Question 2

Encephalitis is?

Primary infection?

Postinfection?

Answer 2

Acute inflamm of brain from Virus

Viral invasion of CNS w/ neuronal involvement,
Virus is identifiable by tissue cx

Immune response w/ neurons spared,
Can’t identify virus

Question 3

Encephalitis etiology? (3)

Answer 3

HSV 1: most C and most important to identify and treat (in temporal lobe)

Arbovirus/U travel-related (West Nile, St Louis, Eastern/Western)

Zoster, EBV, HIV, etc

Question 4

Encephalitis presentation? (5)

Answer 4

HA
AMS
Seizures
Focal defects: hemiparesis, CNs, ↑DTR
PHOTOPHOBIA/NUCHAL RIGIDITY ARE RARE

Question 5

Encephalitis labs? (4)

Imaging? (2)

Answer 5

Same (results will be same as Aseptic Meningitis if meningoencephalitis)
PCR for HSV/Enterovirus
CSF/Blood Cx for virus, bacteria, fungus, mycob
Brain Bx

CT/MRI = normal or abnormal
EEG = abnormal

Question 6

Encephalitis tx? (2)

Answer 6

Acyclovir IV

Seizure prophy

Question 7

Encephalitis prognosis?

Answer 7

Poor neuro recovery if diffuse edema or intractable seizures

HSV = Fatal w/o tx (14% die anyway), 24% get epilepsy

Question 8

Cerebral Abscess is?

U caused by?

Answer 8

Focal infection of capsulized pus

Infection, trauma, surgery

Question 9

Cerebral Abscess from infection: Direct route of spread? (6)

Answer 9

Otitis media
Mastoiditis
Meningitis
Sinusitis
Dental
Head trauma

Question 10

Cerebral Abscess from infection: Hematogenous route of spread? (4)

Answer 10

Pulmonary
Skin
Intra-abdonminal
Pelvic

Question 11

Cerebral Abscess etiology?

Answer 11

U bacteria:
Strep, Staph, G-, Anaerobes

Immigrants:
Parasites

Question 12

Cerebral Abscess presentation? (7)

Answer 12

U non-specific
Unilat HA
Fever
Nuchal rigidity
AMS
Focal deficits
Seizure

Question 13

Cerebral Abscess labs? (2)

Answer 13

CBC w/ diff

Blood Cx x2

Question 14

Cerebral Abscess imaging?

Answer 14

MRI (study of choice) = Ring-enhanced lesion
Early -> poor demarcation, local edema, no necrosis
Late (>2wks) -> necrosis, liquefaction, fibrotic capsule

Question 15

Cerebral Abscess tx?

Answer 15

CT-guided aspiration

ABX 4-8 wks