CNS infections and prion disease Flashcards
Does PrP (prion related protein) or PrPsc (infectious form) have many alpha helices?
PrP
Does PrP (prion related protein) or PrPsc (infectious form) have many beta sheets?
PrPsc
Cornea or dural transplants, as well has hGH infections, can cause transmission of this
Prions
This is the most common prion disease that results in rapid dementia
Creutzfeldt-Jakob Disease
Prions stain positive on this type of stain
Amyloid/congo
Kuru plaques are seen in Creutzfeldt-Jakob Disease, and are made of this
Prion protein
Spongiform encephalopathy, neuronal loss and gliosis are seen in this condition
Creutzfeldt-Jakob Disease
This is usually the first symptom of Creutzfeldt-Jakob Disease
Rapid dementia
Rapid dementia is usually the first symptom of this disease, where myoclonus is also common
Creutzfeldt-Jakob Disease
Death occurs within this amount of time in Creutzfeldt-Jakob Disease
<1 year
This is the relatively specific EEG changes seen in Creutzfeldt-Jakob Disease
Periodic sharp wave complexes
Periodic sharp wave complexes on EEG are relatively specific for this condition
Creutzfeldt-Jakob Disease
14-3-3 protein in CSF is a nonspecific marker of this condition
Creutzfeldt-Jakob Disease
Acute pyogenic meningitis is an infection within this
Subarachnoid space
Neutrophils in membranes and Virchow-Robin spaces, as well as increased vascular permeability (leading to edema, increased intracranial pressure) are seen in this condition
Acute pyogenic meningitis
Why do patients sometimes recover from meningitis but then later develop hydrocephalus?
Eventual meningeal organized fibrosis –> blocking of arachnoid granulations
Meningoencephalitis indicates involvement of this
Parenchyma
Focal signs, seizures, mental status change, behavioral change, and decreased consciousness are atypical of pure meningitis, but may be seen with this
Meningoencephalitis
Splenectomy is a risk factor for develop Acute pyogenic meningitis by this type of organism
Encapsulated organisms
(e.g. Pneumococcus)
Acute pyogenic meningitis by these two organisms present classicially with exudate distributed over base of brain
H. flu
M. tuberculosis
Is Acute pyogenic meningitis a medical emergency?
Yes
What are the levels of protein, glucose, WBCs, and neutrophils in Acute pyogenic meningitis?
Increased protein, WBC, neutrophils
Decreased glucose
Is bacterial or viral meningitis typically milder?
Viral (aseptic)
Is less acute, self limited at 5-14 days
No treatment typically needed
CSF lymphocytic pleocytosis and normal glucose levels are findings of this type of meningitis
Aseptic (usually viral)
What are the levels of protein and glucose in neoplastic meningitis?
Elevated protein
Low glucose
What are the levels of glucose in autoimmune meningitis?
Normal
(may have lymphocytosis)
Meningitis caused by these 3 types of organisms (that are NOT viruses) may present with negative or delayed culture, lymphocytic pleocytosis, and normal glucose
Tuberculosis
Syphilitic
Fungal
What is the levels of glucose in tuberculous meningitis?
Normal
What is the levels of glucose in syphilitic meningitis?
Normal
What is the levels of glucose in fungal meningitis?
Normal
These 3 organisms are the main causes of chronic bacterial meningitis
Tuberculosis
Borrelia burgdorferi
Treponema pallidum
Is encephalitis most commonly due to bacterial or viral infection?
Viral
Does bacterial or viral encephalitis have a higher risk of long term deficits?
Viral
(intellect, motor, speech, psych, epileptic, visual/auditory)
Does viral encephalitis caused by Eastern Equine encephalitis involve severe sequelae?
Yes
Does viral encephalitis caused by EBV have permanent sequelae?
Rarely
Is viral encephalitis caused by HSV serious?
Yes - 70% fatal without antivirals
Radiology in viral encephalitis will involve hyperintensity of this area on T2-MRI
Parenchyma
Personality/behavioral changes, and focal signs/seizures indicate this type of CNS infection
Viral encephalitis
Are microglial nodules and neuronophagia seen in viral encephalitis?
Yes
(also perivascular lymphocytes)
Localized bacterial/fungal infection of brain
Brain abscess
Respiratory sinusitis can cause brain abscess in these brain regions
Frontal, temporal, anterior parietal lobes
Otitis can cause brain abscess in these brain regions
Occipital lobe and Cerebellum
Multiple brain abscesses, at grey-white junction, indicate this route of infection
Hematogenous
Bacterial endocarditis, dental procedures, pulmonary infections, and any bacteremia can cause this type of CNS infection
Brain abscess
These two organisms are the most common causes of brain abscess
Staphlyococcus and Streptococcus
Increased intracranial pressure, focal findings, and neutrophilic are seen in this type of CNS infection
Brain abscess
Ring enhancing lesion, with central liquefactive necrosis and cavitation, peripheral angiogenesis, collagenous capsule, and surrounding gliosis are seen in this type of CNS infection
Brain abscess
Is a higher fever seen in bacterial or viral CNS infections?
Bacterial
Are focal signs more common in bacterial or viral CNS infections?
Bacterial
Are dental procedures more of a risk factor of bacterial or viral CNS infections?
Bacterial
Septic venous thrombosis of cortical veins or sinuses
Suppurative sinus thrombophlebitis
Fever, headache, retro-orbital pain, EOM dysfunction, chemosis and ptosis occur in Suppurative sinus thrombophlebitis of this sinus
Cavernous sinus
Suppurative sinus thrombophlebitis of this sinus is associated with sinusitis and periorbital infection
Cavernous sinus
Suppurative sinus thrombophlebitis of this sinus can cause headache, fever, nausea, vomiting, and confusion
Superior sagittal
Suppurative sinus thrombophlebitis of this sinus is associated with meningitis or SDE, abscess
Superior sagittal
Meningococcal meningitis occurs in this age group
Children and young adults
Meningitis with this organism often involves petechial hemorrhages of skin
Meningococcal
This type of meningitis is associated with Waterhouse-Friederichsen syndrome
Meningococcal
Meningococcal meningitis is associated with this syndrome, involving dissemianted intravascular coagulation
Petechial-purpuric rash
Bilateral adrenal hemorrhage
Rapid hypotension and shock
Waterhouse-Friderichsen Syndrome
Petechial-purpuric rash is common in meningitis with this organism
Meningococcal
This is a capsulated yeast that causes meningitis most commonly in immunosuppressed, HIV esepcially
May invade V-R spaces to produce abscesses or meningoencephalitis
Cryptococcal
Meningitis caused by this organism will be Mucicarmine positive, and detected by India Ink test
Also GMS stain
Cryptococcal
This is dimorphic yeast with mucoid capsule
Capsule allows evasion of host response
Proliferates in CSF
Produces gelatinous/mucoid coating of brain
Cryptococcal
This organism invades brain to produce cystic spaces with gelatinous appearance
“soap bubbles”
Cryptococcus
Where does Cryptococcus proliferate in the CNS?
In CSF
This is the second most common cause of viral meningitis
Herpes (mostly HSV-2)
This is the most common form of Mollaret’s meningitis
(recurrent lymphocytic meningitis)
Herpetic meningitis
Herpetic encephalitis typically occurs in this part of the brain
Inferior medial temporal lobes
(via olfactory bulbs)
This virus that can cause encephalitis tends to infect the inferior medial temporal lobes, via olfactory bulbs
Herpes
Hyperintensity on medial temporal lobe could be this condition
Herpetic encephalitis
This is the drug of choice for herpetic encephalitis
Acyclovir
Cowdry A inclusions are seen in encephalitis caused by this virus
Herpes (usually HSV-1)
Meningitis caused by this virus produces a panencephalitis (vesiculopustular lesions)
Highest risk with primary maternal infection
Herpes
Chronic progressive demyelinating encephalitis due to delayed reactivation of measles infection
Subacute sclerosing panencephalitis
A child with intellectual decline/dementia and myoclonic jerks could have this condition
Subacute sclerosing panencephalitis
How is Subacute sclerosing panencephalitis diagnosed?
CSF IgG for measles
Neuroparenchymal form of tertiary syphilis
Neurosyphilis
Is Syphilitic meningitis serious?
Mild; often resolves spontaneously
Syphilitic meningitis occurs this much time after primary infection
<1 year
(usually during secondary phase)
Tabes dorsalis occurs this much time after primary infection with syphilis
15-20 years
Tabes dorsalis is a chronic inflammation of these 3 sensory regions
Dorsal columns
Dorsal root ganglions
Dorsal nerve roots
This condition involve demyelination and loss of fibers in dorsal root ganglion and dorsal roots
Favors lumbar region and gracile fasciculus
Tabes dorsalis
Symptoms of this condition involve lightning pains, paresthesias, loss of sensation/proprioception, shuffling gait, drop foot, and loss of DTR’s
Tabes dorsalis
Charcot joint is joint destruction due to sensory loss, and is seen in this condition which occurs after syphilis infection
Tabes dorsalis
A man who had syphilis 20 years ago that now presents with loss of sensation in his feet may have this condition
Tabes dorsalis
Tabes dorsalis favors sensory regions in these areas
Lumbar region and gracile fasciculus
This is a pupil that reacts to accommodation but not light
Occurs in Tabes dorsalis
Argyle-Robinson pupil
Argyle-Robinson pupil is seen in this condition
Tabes dorsalis
(neurosyphilis)
General paresis (of the insane) is a late stage complication of this infection
Syphilis
General paresis (of the insane) occurs this many years after primary syphilis infection
10-20 years
This late complication of syphilis involves insidious mental decline, psychiatric manifestations, seizures, loss of motor control, and eventual coma and death
(“PARESIS”)
General paresis (of the insane)
“PARESIS” is an acronym for symptoms of this late stage complication of syphilis
(Personality, affect, reflexes increased, eye (A-R pupil), sensorium, intellect, speech)
General paresis (of the insane)
This bacteria causes syphilis
Treponema pallidum
Spiral-shaped bacteria with lymphoplasmacytic inflammation, often vascular/perivascular are seen in this CNS infection
Silver stains highlight organisms
Neurosyphilis
Will there be culture growth in Neurosyphilis?
No growth
RPR/VDRL are non-specific serology tests for this CNS infection
Neurosyphilis
Thoracic aortic aneurysm, aortic insufficiency, plasma cell infiltrates in lesions, and obliterative endarteritis in lesions are other clinical clues of this CNS infection
Neurosyphilis
Polio virus is a lytic picornavirus infection of this type of neuron
Motor
This virus causes a predominantly LMN disease of anterior horn cells
Neuron loss and gliosis
Polio
Most CNS infections with this virus involve asymmetric weakness
Bulbar or diaphragmatic involvement may occur
LMN disease (flaccid paralysis with atrophy)
Polio
What is the typical incubation period of rabies?
1-3 months
These are the two forms of rabies
Furious and Dumb rabies
Form of rabies involving hyperexcitable neurons
Severe pain with light touch
Pharyngeal spasm
Terminal coma/death
Crazy rabies
Form of rabies involving somnolence and flaccid paralysis
Terminal coma/death
Dumb rabies
CNS infection with this virus involves widespread microglial nodules and neuronophagia
Favors cerebellum and hippocampus
Rabies
Rabies favors these two parts of the brain
Cerebellum and Hippocampus
This is the pathognomonic inclusion seen in infection with Rabies
Negri body
(round eosinophilic cytoplasmic inclusion)
Negri body is a pathognomonic inclusion seen in infection with this virus
Rabies
HIV infection of these cells leads to gliosis
Gradual dementia predominantly of executive function
CD4+ microglial cells
Microglial nodules with multinucleated microglial cells are seen in CNS infection with this virus
MRI shows generalized atrophy and white matter enhancement
HIV
(HIV-associated neurocognitive disorder = HAND)
What is the key morphological feature in HIV-associated neurocognitive disorder (HAND)?
Microglial nodules with multinucleated microglial cells
These are the two forms of CNS infection by Mycobacterium tuberculosis
Chronic meningitis and Tuberculoma
Chronic meningitis from tuberculosis usually spreads from lesion at this location
Pulmonary cavity
What are the levels of protein in tuberculosis CNS infection?
Very high
What are the levels of glucose in tuberculosis CNS infection?
Normal
Obliterative endarteritis of SAS arteries (causing ischemic CVA) and meningeal fibrosis are complications of CNS infection with this bacteria
Tuberculosis
CSF with VERY high protein, normal glucose, and monocytes are seen in chronic meningitis caused by this bacteria
Tuberculosis
This is a mass of caseous necrosis, with surrounding granulomatous inflammation
Multinucleated giant cells and acid fast organisms
Tuberculoma
Aspergillus fungus infects immunosuppressed patients, especially with this
Neutropenia
This organism is seen in immunosuppressed patients, especially neutropenia
Aspergillus fungus
Aspergillus fungus is especially invasive to this part of the body
Blood vessels
(angioinvasive)
Produce multifocal hemorrhagic masses
This organism is angioinvasive and produces multifocal hemorrhagic masses
High mortality rate
Aspergillus fungus
Morphology of this fungus has uniform hyphae, 45 degree branching, septate
Aspergillus fungus
Mucormycosis is CNS infections with Zygomycete fungus (Mucor and Rhizopus species), that is most common in patients with this condition
Diabetes (especially ketoacidosis)
Mucormycosis of the CNS involves direct venous invasion through this
Orbital plate
(from facial/nasal skin/mucosa)
Characteristics of this CNS infection is rapid progression of hemorrhagic, necrotic naso/facial infection
Orbirtal involvement
Black, necrotic eschar at initial site
Death in a few days
Mucormycosis
Morphology of this fungus is variable caliber (thick or thin), aseptate, with 90 degree branching
Mucormycosis
The typical patient with Cryptococcus infection has this condition
HIV
The typical patient with Aspergillus infection has this condition
Neutropenic
The typical patient with Mucormycosis infection has this condition
Diabetes
Morphology of this fungal infection has encapsulated yeast, mucoid
Cryptococcus
Morphology of this fungal infection has 45 degree, septate, uniform hyphae
Aspergillus
Morphology of this fungal infection has 90 degree, aseptate, broad variable hyphae
Mucormycosis
Is Aspergillus septate or aseptate?
Septate
Is Mucormycosis septate or aseptate?
Aseptate
Does Aspergillus have uniform or variable hyphae?
Uniform
Does Mucormycosis have uniform or variable hyphae?
Variable
Does Aspergillus have 45 or 90 degree hyphae?
45 degree
Does Mucormycosis have 45 or 90 degree hyphae?
90 degree
This fungal infection usually occurs with rhinocerebral extension
Mucormycosis
CNS deposition of Taenia solium larva
Neurocysticercosis
Neurocysticercosis is CNS deposition of this organism
Taenia solium
Most infections with Taenia solium are asymptomic unless in these two organ systems
CNS or heart
Do viable cysts of Taenia solium elicit inflammation?
No
(may be asymptomatic for months/years)
Degeneration produces inflammation and edema
Multiple cysts seen on imaging, with no enhancement if viable cysts, as well as enhancement or calcified if dead/degenerating, is seen in this condition
May see scolex
Neurocysticercosis
