CNS Infections

Question 1

What infectious agent causes progressive multifocal leukoencephalopathy (PML)?

Answer 1

JC virus

Question 2

What cells does JC virus infect?

Answer 2

Oligodendrocytes

Question 3

What medicine used to treat multiple sclerosis has resulted in cases of progressive multifocal leukoencephalopathy, several of them fatal?

Answer 3

Natalizumab (Tysabri)

Question 4

Parasite that spreads by ingestion of infected meat or the feces of an infected cat, or by vertical transmission from mother to fetus.

Answer 4

Toxoplasma gondii

Shows as eccentric target sign on MR

Question 5

What is the main differential of a ring-enhancing lesion in a patient with AIDS?

Answer 5

Toxoplasmosis vs. primary CNS lymphoma

Question 6

Testing the CSF for what is specific and sensitive for CNS lymphoma?

Answer 6

Ebstein-Barr virus PCR

Question 7

Survival for primary CNS lymphoma

Answer 7

Usually <6 months, too sick to tolerate chemotheraphy

Question 8

Treatment for suspected toxoplasmosis:

Answer 8

Empiric treatment with sulfadiazine and pyrimethamine.

Question 9

What is cryptococcus?

Answer 9

A yeast that typically presents as a lung infection.

Question 10

What two tests are used to help diagnose cryptococcus?

Answer 10

India ink stain is positive in 75% and cryptococcal antigen via latex agglutination test is positive in CSF in 95% of cases.

Question 11

What are the main opportunistic CNS infections in HIV?

Answer 11

CMV, PML, toxoplasmosis, and cryptococcus.

Question 12

Most common cause of sporadic encephalitis in the US?

Answer 12

HSV encephalitis

Question 13

How does HSV encephalitis present?

Answer 13

Fever, headache, confusion, personality changes, olfactory/gustatory hallucinations. Or focal seizures and motor disturbances.

Question 14

A positive LP for HSV encephalitis will show what?

Answer 14

Grossly bloody CSF with an elevated white count, mostly lymphocytes. HSV PCR confirms diagnosis.

Question 15

Where in the brain is HSV usually seen?

Answer 15

Frontal and temporal lobes.

Question 16

What is tropical spastic paraparesis? What causes it?

Answer 16

A chronic myelopathy common in the Caribbean and Africa, found in the US in IVDU. Caused by Human T-lymphotropic virus type I.

Question 17

Where is reactivated varicella located?

Answer 17

dorsal root ganglia

Question 18

Rabies biopsy will show what?

Answer 18

Negri bodies

Question 19

What does polio affect?

Answer 19

Directly infects the anterior horn cells of the spinal cord.

Question 20

What is the most common cause of bacterial meningitis in neonates?

Answer 20

Streptococcus agalactiae (GBS)

Question 21

Steps if high concern for meningitis:

Answer 21

1. Blood Cx
2. Empiric Abx
3. LP, unless patient has focal neuro deficits, papilledema, immunocompromise, Hx of CNS disease, or AMS, then get CT to r/o other causes.

Question 22

Empiric Abx treatment for suspected meningitis:

Answer 22

3rd gen cephalosporins like cefotaxime/ceftriaxone + vancomycin.

Question 23

Characteristics of CSF in bacterial meningitis:

Answer 23

Decreased glucose concentration, elevated opening pressure, increased protein, cloudiness of CSF, polymorphonuclear pleocytosis.

Question 24

What is Kernig’s sign?

Answer 24

Positive when there is pain when the thigh is bent at the hip and knee at 90 degrees.

Question 25

What is Brudzinski’s sign?

Answer 25

Positive when there is involuntary lifting of the legs when lifting a patient’s head off the exam table with the patient lying supine.

Question 26

Though is remains a subject of controversy, what symptom have steroids been shown to help in patients with bacterial meningits?

Answer 26

Prevention of hearing loss

Question 27

Pott’s disease

Answer 27

TB infection of the vertebral bodies, most commonly localized in the lower thoracic or upper lumbar spine.

Question 28

Three clinical categories of CNS TB:

Answer 28

meningitis, intracranial tuberculomas, spinal tuberculous arachnoiditis

Question 29

To prevent stocking-glove neuropathy in patients being treated for TB must take which supplement?

Answer 29

Pyridoxine/Vitamin B6

Question 30

What are Argyll Robertons pupils?

Answer 30

Pathognomonic for neurosyphilis. The pupil accomodates, but does not react to light.

Question 31

What is Tabes Dorsalis?

Answer 31

Inflammatory destruction of lumbosacral dorsal root ganglia with loss of sensation and pain in the legs and abdomen, damage to posterior columns of spinal cord. Due to Tertiary (neuro) syphilis.

Question 32

What are two non-specific markers for syphilis?

Answer 32

rapid plasma reagin (RPR), Venereal Disease Research Laboratory (VDRL). Both detect cardiolipin antibodies.

Question 33

What do you use to treat neurosyphilis?

Answer 33

IV or IM penicillin for 14 days.

Question 34

Lyme disease is caused by infection with what?

Answer 34

Borrelia burgdorferi

Question 35

Treatment for Lyme disease:

Answer 35

Oral doxycycline or IV ceftriaxone if neuro symptoms have developed.

Question 36

What is Naegleria fowleri?

Answer 36

The “brain-eating amoeba” found in warm bodies of fresh water, such as ponds, lakes, rivers, and hot springs.

Question 37

What is Taenia solium?

Answer 37

A pork tapeworm, causes cysticercosis.

Question 38

Primary cause of acquired epilepsy in India and South America?

Answer 38

Cysticercosis

Question 39

Treatment for cysticercosis:

Answer 39

Albendazole and steroids to reduce inflammation.

Question 40

What is the double hockey stick sign on MR?

Answer 40

Creutzfeldt-Jakob disease

Question 41

How does CJD look on MR?

Answer 41

Cortical ribboning: spongiform degeneration of the gray matter caused by neuronal loss.

Question 42

What is Kuru?

Answer 42

A spongiform encephalopathy formerly seen in New Guinea, due to consumption of human brain tissue.

Question 43

Presentation of CJD:

Answer 43

Clinically presents as very rapid onset dementia that is fatal within a matter of months, commonly associated with myoclonus.