Neuroinfectious Flashcards
In patients with HIV aseptic meningitis, alertness and cognition are deeply affected. True or False?
False. In patients with HIV aseptic meningitis, alertness and cognition are preserved, distinguishing it from encephalitis and meningoencephalitis.
What is the pathophysiology behind aseptic meningitis in HIV?
It is part of the seroconversion syndrome in HIV. May appear during the initial stages of HIV infection
What is the CSF finding of HIV aseptic meningitis?
The CSF of these patients usually shows a lymphocytic pleocytosis (but usually less than 25 cells/uL) and mildly increased protein level (less than 100 mg/dL), with normal glucose levels.
Patient presented with bell’s palsy and lymphocytic meningitis. What is the possible organism involved and vector?
Borrelia burgdorferi. This spirochete is transmitted by the deer tick Ixodes.
What is the management of Lyme disease (First Stage: Rash and Cranial Neuroapthies)?
First stage (Rash and cranial neuropathies) • oral doxycycline 100mg BID x 14 days alternate: Amoxicillin 500mg TID; Cefuroxime axetil 500mg BID
What are the predisposing factors in the development of mucormycosis?
Diabetes mellitus and diabetic ketoacidosis are major and frequent risk factors
Others:
- malignancies
- high-dose steroids
- organ transplantation
- immunosuppression
- iron chelation therapy (with deferoxamine)
What is the spectrum of cognitive disorder of HIV?
asymptomatic neurocognitive impairment (ANI)
minor neurocognitive disorder (MND)
HIV-associated dementia (HAD)
What is the CD4 count in patients with HIV and HAD?
patients with CD4 counts below 200 cells/mm3
What are the main clinical manifestations of HIV-associated neurocognitive disorder?
Progressive cognitive decline and prominent psychomotor dysfunction are the main clinical manifestations.
These patients have significant difficulties with attention and concentration, along with fine motor dysfunction, gait incoordination, and tremors.
What is the neuropathologic finding in HIV-associated dementia?
diffuse white matter pallor, mononuclear infiltrates, multinucleated giant cells, and vacuolar changes in the brain. The main findings are in the subcortical region, and the cerebral cortex is relatively spared.
HIV-associated dementia may be prevented. True or False?
HIV-associated dementia can be prevented by adequate early treatment of HIV with highly active antiretroviral therapy (HAART), with the goals of attaining higher CD4 counts and suppressing the virus.
HIV-associated dementia leads to improvements in neuropsychological performance. Prognosis is generally good, likely given the early stage of HIV in which this condition develops. True or False?
False.
Prognosis is generally POOR likely given the LATE stage of HIV in which this condition develops
While you are working your 4th-of-July shift in the emergency department, a 62-year-old farmer is brought with mental status changes and generalized weakness. The patient has been having low-grade fevers, malaise and back pain, body aches, and headaches for the past 10 days; however, he did not want to come to the hospital. Over the past 5 days, he has developed bilateral hand tremors and difficulty walking. About 3 days ago, he became confused, and today, he was noticed to be unable to move his legs. On examination, he is lethargic and confused and noticed to be flaccid in his lower extremities, with areflexia. Which of the following is the most likely diagnosis?
a. Tuberculous meningitis and Pott’s disease
b. Subacute combined degeneration of the spinal cord c. Neurosyphilis with tabes dorsalis
d. West Nile encephalitis
e. HSV encephalitis
D. West Nile virus (WNV) encephalitis
Trasmitted by: Culex
severe neurologic presentation will have manifestations of encephalitis; however, WNV can also invade the anterior horn cells leading to flaccid weakness with arreflexia, similar to poliomyelitis
What is the histopathologic finding in Crytococcal meningitis?
histopathologic specimen demonstrates budding yeasts near blood vessels and surrounded by an inflammatory infiltrate,
What is the CD4 count in patients at risk of developing cryptococcal meningitis?
CD4 counts fall below 100 cells/uL
What is the treatment of cryptococcal meningitis?
• Intravenous administration of Amphotericin B (0.7-1.0mg/kg/day) or (3-4mg/kg/day) of liposomal amphotericin continued for 6wks
Addition of flucytosine (100mg/kg/d)
What is the most useful diagnostic test in cryptococcal meningitis?
India ink smear is not very sensitive; however, it is useful when it is positive
Cryptococcal antigen detection in the CSF is rapid, sensitive and specific, and clinically useful, since fungal culture may take several days to weeks for a positive result to be obtained.
What are the side effects of amphotericin and flucytosine therapy?
Amphotericin is associated with renal failure, hypokalemia, and hypomagnesemia; and flucytosine may cause hematologic abnormalities.
What is the histopathologic findings of toxoplasma?
Microglial nodule, in which an encysted bradyzoite can be seen surrounded by an inflammatory infiltrate.
What is the CD4 count in patients at risk of developing toxoplasmosis of the CNS?
CD4 counts fall below 100 cells/uL
What is the treatment of CNS toxoplasmosis?
• a presumptive diagnosis can be made on a clinical basis in a patient with HIV and empiric treatment is started before confirmatory testing
• oral sulfadizine (4g then 4-6g daily) + Pyrimethamine (200mg then 50-100mg OD) • Leucovorin 15-20mg OD- counteract the anti-folate action of pyrimethamine completed for 6wks
What is the prophylaxis for Toxoplasmosis and when it is given?
Trimethoprim-sulfamethoxazole
Given to:
- Patients with HIV
- CD4 counts of less than 100/uL
- positive IgG antibodies to toxoplasma
What is the MRI finding of Primary CNS Lymphoma (PCNSL) in the setting of AIDS?
MRI shows one or more lesions usually in the periventricular and deep regions of the brain. lesions may have contrast enhancement, surrounding edema, and produce mass effect.
Patient was diagnosed with end-stage AIDS. Presenting with progressive course of multiple focal neurologic manifestations, with visual field deficits and visual agnosias. MRI shows multiple white matter nonenhancing lesions that tend to coalesce and predominate in the parieto-occipital regions. What is the likely diagnosis and what is the gold standard of treatment?
Progressive Multifocal Leukoencephalopathy
Brain Biopsy is the gold standard diagnostic test
What is the neuropathologic finding of Progressive Multifocal Leukoencephalopathy?
myelin loss, giant astrocytes, and altered oligodendrocytes, with enlarged nuclei and viral inclusions. On electronic microscopy, the viral particles give a “spaghetti and meatballs” appearance.
What is the clinical manifestation of HIV neuropathy?
predominantly sensory, axonal length-dependent symmetric polyneuropathy.
It is thought to be related to direct effects of the virus and cytokine upregulation.
HIV pt presented with numbness that occurs over weeks following the initiation of therapy. the The treatment is to discontinue the offending drug. What is the diagnosis?
Nucleoside analog-associated neuropathy
Patient presents with iridocyclitis + depigmentation of thick swath of hair + skin, vitiligo + loss of eyelashes, dysacusis and deafness. What is the diagnosis?
Vogt-Koyanagi-Harada Syndrome
Which of the following is the least common pathogens of bacterial meningitis in neonates? A. Escherichia coli, B. Enteric gram-negative bacilli C. Listeria monocytogenes D. group B streptococci E. Neisseria mengitidis
E. Neisseria mengitidis
In patients who undergo neurosurgical intervention, which of the following is the least likely etiology of meningitis?
A. Pseudomonas aeruginosa
B. Staphylococcus aureus C. Staphylococcus coagulase negative (epidermidis)
E. Propionibacterium Acnes
F. Streptococcus pneumonia
F. Streptococcus pneumonia
What is the most commonly affected region in Pott’s Disease?
Thoracic spine
Which of the following is least likely true of mycobacterium tuberculosis spine involvement?
a. It spreads via hematogenous route to the vertebral bodies
b. Spinal disease starts at the spinous process.
c. Infectious process later spreads to the central part of the vertebral body and intervertebral disk
D. With progression of the infection there is disruption of the bone and the intervertebral spaces
B. Spinal disease starts at the anterior region of the vertebral bodies, not at the spinous processes.
What is the tropism of Mycobacterium leprae?
Tropism toward peripheral nerves (Schwann cell), especially in cooler areas of the body.
What are the 2 variants of Leprosy?
Give some differentiation
Lepromatous variant
- occurs in impaired cell-mediated immunity
- systemic symptoms;
Tuberculoid Variant
- may occur in patients with good cellular immunity
- skin lesions are better localized
What is the histopathologic finding of Leprosy?
demonstrating inflammatory granulomas with epithelioid and mononuclear infiltrates and acid-fast organisms.
What are the most commonly affected nerves in leprosy?
Ulnar Nerve (most common) Greater Auricular Nerve Radial Nerve Common Peroneal Nerve Sural Nerve
What is the appropriate treatment for Neisseria meningitides?
Penicillin G (Procaine and Probenicid) IV 18-24 million units per day (3-4 millions units q4) for 10-14 days
What is the appropriate treatment for Streptococcus pneumoniae?
vancomycin and ceftriaxone, and the duration of treatment is between 10 and 14 days.
What is the appropriate treatment for Listeria monocytogenes?
extremes of age (younger and older) and in immunocompromised patients, should be treated with ampicillin for more than 21 days
