CNS infections Flashcards
(32 cards)
1
Q
PML: Progression Multifocal Leukoencephalopathy
A
- Caused by JC virus : infects oligodendrocytes
- Characterized by confluent white matter T2 hyperintensity.
- Detecting JC virus in the CSF via PCR is a confirmatory test
- Tx in AIDS patient is by starting HAART therapy
- MS patients on Tysabri have increased risk of PML
2
Q
Risk factors for PML on Tysabri
A
- . Prior exposure to JC virus is a requirement. Antibody test to determine who has been exposed. Pt who are negative for JCV antibody have essentially 0 % risk
- Prior immunosuppression doubles risk
- Number of tysabri infusions: the risk is very low in the 1st yr and higher after 2nd yr
3
Q
Toxoplasmosis
A
- parasitic infection caused by Toxoplasma gondii. Cats are primary hosts
- Spread by ingestion of infected meat or feces of infected cat or vertical from mom to fetus
- Usually cause flu-symptoms and then nothing else in healthy ppl
- Appears a ring enhancing lesion on MRI: DDx in AIDS pts: Toxo and primary CNS lymphoma. pt should be tested for antibody for toxo but only helps if it is negative then that means it is probably CNS lymphoma testing CSF for EBV PCR is sensitive and specific for CNS
4
Q
Tx for toxo
A
Sulfadiazine and pyrimethamine
5
Q
Cryptococcus
A
- Yeast that typical present as lung infection
- In immunocompromised pts cryto meningitis can have very indolent course with headaches, mental status changes and meningeal signs.
6
Q
Dx of Crypto meningitis
A
- India ink stain of CSF is positive in 75 percent, cryptococal antigen cia latex agglutination test is positive in CSF in 95 of cases ( f this test is negative then no rypto)
- LP reveals elevated opening ICP and papilledema
7
Q
HIV associated neuro probs
A
- Myopathy: can be due to meds AZT
- Neuropathy: chronic painful distal polyneuropathy. Can be meds
- Myelopathy: Can produce a myelopathy similar to b12
- Meningitis: Can produce syndrome like any meningitis
- Dementia: HIV dementia is common in late stages
- Eye disease: retinitis is due to CMV infection. CMV can cause lumbar radiculitis
Stroke: can be cause by HIV vasculitis
8
Q
HSV encephalitis
A
- Most common cause of sporadic encephalitis in US
- Can p/w fever, headache, confusion, personality changes and olfactory/gustatory hallucination or seizures and motor disturbance.
- Predilection for frontal and temporal lobes and with massive swelling pts at risk for uncal herniation
- LP = grossly bloody CSF with an elevated white count ( mostly lymphs). HSV PCR = confirmation. EEG : periodic lateralized epileptiform discharges particularly over temporal lobes.
- TX: IV acyclovir
9
Q
Human T-lymphocytic virus type 1
A
Causes tropical spastic paraparesis.
- Chronic myelopathy common in Caribbean and Africa. ( hyperreflexic in the legs with upgoing toes and cannot lift legs.)
10
Q
Herpes Zoster: shingles
A
Reactivation of varicella infection in dorsal root ganglia
- usually in thoracic dermatome ( when in V1 = zoster ophthalmicus)
- tx: a week of antiviral agents ( acyclovir or valacyclovir)
- Can invafe cerebral arteries causing stroke or spinal cord
11
Q
CMV
A
Can cause devastating infection in utero
- In immunosuppressed can cause encephalitis often fatal within a few months
- often associated with retinitis
12
Q
Rabies
A
- occurs after a bitch from an infected animal
- Can cause encephalitis that leads to psych disturbances followed by seizures and death or a fatal paralysis due to infection of spinal cord
- Biopsy : negri bodies
13
Q
Polio
A
- directly infects the anterior horn cells of the spinal cord
14
Q
West nile
A
Can also affect anterior horn cells
15
Q
Bacterial meningitis
A
- Nucal rigidity,
- photophobia,
- mental confusion,
- LP = increased WBC, neutrophils,
- Positive gram stain ( pneumococcus)
_ pneumococus and N. meningitis most common causes in adults. - L monocytogenes in those over 50
16
Q
Most common cause of bacterial meningitis in neonate?
A
Group B Strep: Strep agalactiae
17
Q
Dx of bacterial meningitis
A
- Blood cx. and empirically start broad spectrum Abx: third generation cephalosporins/ ceftrioxone
- LP is the next step to confirm Dx unless pt has focal neuro deficits, papilledema, immunocompromise, hx of CNS disease or altered mental status then you have to get a CT to rule out other causes of their symptoms because LP can cause herniation in someone with a mass.
18
Q
CSF of pt with B meningitis
A
- Decrease glucose
- polymorphonuclear ( PMN) pleocytosis .
- elevated opening pressure
- cloudiness of CSF
19
Q
Tx of bacterial meningitis
A
- empirically treat as soon as suspected
- 3rd generation cephalosporin: Ceftriaxone with addition of ampicillin in neonates and pt older than 50
20
Q
kernig sign
A
- positive when there is pain when the thigh is bent at the hip and knee at 90 degrees
21
Q
Brudzinski’s sign
A
- positive when there is involuntary lifting of the legs when lifting a pts head off the examining table with pt supine.
22
Q
What symptom have steroids been shown to help in pt with bacterial meningitis
A
Deafness.
- Steroids should be given prior to the first dose of Abx.
23
Q
Severe low back pain and weakness in legs and incontinence + MRI showing pathologic fracture of Thoracic or lumbar vertebrae
A
- Infectious cause most likely Pott’s disease : hematogenous spread of TB to vertebrae and into the adjoining intervetebral space. Most commonly in lower thoracic or upper lumbar spine
24
Q
Three categories of CNS TB
A
- Meningitis : affects basal areas of brain : fever, malaise, stupor and coma ,seizures and sometimes hemiparesis
- intracranial tuberculoma
- spinal tuberculour arachnoiditis .
TX: RIPE: rifampin, isoniazid, pyrazinaminde for 12 months ( must take vitamin B6 to prevent peripheral neuropathy with RIPE)
25
Abscess
Usually presents with focal neuro deficits. on radiographic appearance ring enhancing.
- presence of multiple suggests hematogenous spread
26
Syphilis
- Primary Syphilis: painless chancre
- Secondary: flu-like symtpoms, rash on palms and soles of fete and condyloma lata
- Tertiary : 10-30 ys after infections. Meningitis/ vasculitis: can cause strokes in MCA distribution.
Tabes Dorsalis: inflammatory destruction of lumbosacral dorsal root ganglia with loss of sensation and pain in the legs and abdomen, damage to the posterior columns. ( Constricted pupils non reactive to light but reactive to accomodation)
General Paresis: an encephalitis infection characterized by dementia and psych symptoms
27
Dx of neurosyphilis
- No lab sufficient
- Nontreponemal tests: RPR and VDRL ( reactive within a couple of weeks and can give false pos in older age, autiimune disease IV drug use.)
- Trepnemal test: TP-PA: specific
- Treponemal screen, non treponemal confirmation
- LP needed for neurosyphillis often shows a high CSF WBC and presence of oligoclonal bands
28
TX of syphilis
- Penicillin IV or Im for 14 days . Follow up blood tests at 3,6,12,24 and 36 months. Reevaluate CSF every 6 months to 3 years to ensure successful treatment
29
Lyme disease
- Caused by Borrelia burgdoferi;
( can affect facial nerve)
- Stage 1: acute infection: erythema migrans
- Stage 2: Flu-like symptoms meningitis, cardiac pathology
Stage 3: sensory neuropathy, subtle cognitive changes in some
Tx: oral doxycycline or if neuro symptoms IV ceftriaxzone;
30
Cysticercosis
Caused by taenia solium: pork tapeworm
- Common in India and South America --> primary cause of epilepsy
- Fecal oral spread
- Cysts infect muscles, the brain or eyes.
- can grow in ventricles most commonly 4th leading to hydrocephalus ( racemos neurocystercercosis)
- Tx: albendazole and steroids to reduce inflammation
31
Naegleria Fowleri
Brain eating ameoeba found in warm bodies of fresh water
32
CJD: Creutzfeldt-Jakob disease
- Presents as very rapid onset dementia fatal within months and commonly associated with myoclonus.
- caused conformational change of a prion protein
- Mostly sporadic
- Pathologically: spongiform degeneration of the grey matter
- CSF may show 14-3-3 protein ( not specific)
- EEG: periodic sharp waves
