Path- 4: Infections Flashcards
What is the most common way infections can enter the brain?
Hematogenous spread via arteries or veins
What type of mechanism of injury causes direct implantation of bugs tot he brain?
trauma
What does TORCH stand for that are the group of diseases that cause congential conditions?
Toxoplasmosis, Other (syphilis, varicella, mumps, parovirus and HIV), Rubella, CMV, Herpes
What is meningitis?
inflammatory process of leptomeninges and CSF
What is meningoencephalitis?
inflammation of meninges and brain parenchyma
What is the main cause of acute pyogenic meningitis?
bacteria
What is the main cause of aseptic meningitis?
viral meningitis
What is the main cause of chronic meningitis?
TB, spirochetes, cryptococcus
What is normal CSF pressure (in mmHg)?
10-18mmHg
When the pts lie on their side for an LP, what is the new pressure in the CSF?
20-30mmHg
What condition causes in increased in the IgG content of the CSF?
MS
What is the main causitive agent for acute pyogenic meningitis in neonates?
Strep. agalactiae
What other bugs cause acute pyogenic meningitis in neonates?
E. coli, Strep pneumo, Listeria monocytogenes
What is the main causitive agent for acute pyogenic meningitis in adolescents/young adults?
Neisseria meningitidis
What is the main causitive agent for acute pyogenic meningitis in IV drug users?
Staph aureus
What is the main causitive agent for acute pyogenic meningitis in children and adults?
Strep pneumo
What are the Sx of acute pyogenic meningitis?
headache, photophobia, irritability, nuchal rigidity, nausea, vomiting.
What is the CSF content on spinal tap in acute pyogenic meningitis?
cloudy CSF, increased pressure, increased neutrophils, increased protein, decreased glucose
What is waterhouse-fridreichsen syndrome?
results from meningitis-assocaited septicemia (N. meningiditis), it’s a hemorrhagic infarction of the ADRENAL glands, causes cutaneous petechiae, in kids.
What again is the main causitive agent of acute aseptic meningitis?
Viruses
What is the CSF content on spinal tap in acute aseptic meningitis?
CSF glucose normal, protein slightly elevated, lymphocytes present
What is the Tx of acute aseptic meningitis?
Nothing, it’s self-limiting.
What is the most common viral cause of acute aseptic meningitis?
enterovirus (polio, echovirus, coxackievirus)
What are the physiological changes in acute aseptic meningitis?
Brain swelling, mild leptomeninges infiltration
What causes drug-induced aseptic meningitis?
NSAIDs, antibiotics
What is the CSF content on spinal tap in Drug-induced aseptic meningitis?
glucose normal, neutrophils present, increased CSf protein
What causes brain abscesses?
variety of routes, often from primary infected site int he heart (endocarditis), lungs, teeth or bones.
What are the msot common abcteria to cause brain abscesses?
Strep and staph
True or false: cerebral abscesses are destructive lesions
True
What is the pathological findings to abscesses?
Central liquefactive necrosis surrounded by a fibrous cap, often in frontal or parietal lobes or the cerebellum, have progressive focal deficits
True or False: Brain abscesses do not cause an increase in ICP
False
What is seen on CT’s for a brain abscess that organizes?
Collagen deposition around a ring enhancing lesion
What types of Tx’s are there to decrease the lethality of brain abscesses to < 10%?
Surgerya nd antiobiotics
How can one get subdural empyema?
bacteria and fungi can spread to subdural space –> subdural empyema
What are the Sx of subdural empyema?
Febrile, headaches, neeck stiffness, if untreated –> coma, CSF profile similar to abscesses
What are extradural abscesses commonly assocaited with?
Osteomyelitis (of the adjacent bone)
What are the Sx of chronic bacterial meningoencephalitis from TB?
headaches, malaise and confusion, vomiting
What is the CSF like on bacterial meningoencephalitis from TB?
moderate pleocytosis, proteins are very high, glucose slightly decreased or normal.
Where is the fibrous exudate from the subarachnoid space usually located?
at the base of the brain, obliterating the cisterns and encasing the CN’s
What are the most serious problem with chronic bacterial meningoencephalitis from TB?
arachnoid fibrosis (causing hydrocephalus) and obliterative endarteritis (causing arterial occlusion)
What causes neurosyphilis?
Tertiary syphilis
What are the major forms of meningovascular neurosyphilis?
Paretic and tabes dorsalis
What is meningovascular neurosyphilis?
Chronic meningitis involving th ebase of the brain, spinal leptomininges and cerebral convexitis. May cause oliterative endarteritis (Heubner arteritis)
What is paretic neurosyphilis?
Invasion of the brain by T. pallidum, progressive loss of mental and physical fxns with mood alterations
What causes Tabes dorsalis?
damage by the spirochete to the sensory nerves in the dorsal roots, causing locomotor ataxia and sense of position, loss of pain sensation
Physical exam of a Tabes dorssalis pt will reveal what anomaly?
+ Rhomberg’s sign
What causes neuroborreliosis?
Borrelia burgorferi (Lyme disease)
What are the Sx of neuroborreliosis?
aseptic meningitis, facial nerve palsies, mild encephalopathy, polyneuropathies
What are the most characteristic features of viral meningoencephalitis?
perivascular and parenchumal mononuclear cell infiltration
Intrauterine viral infections from Rubella may cause what in the baby?
Congenital malformations
Many years after the viral infection may cause what?
Slowly progressive degenerative diseases
What is the virus that is an important cause of epidemic encephalitis, especially in tropical regions, and is spread by arthopods?
Arbovirus
What are the Sx to arthropod-borne viral meningoencephalitis?
Szrs, confusion, delirium, stupor and coma
What are the CSF findings to arthropod-borne viral meningoencephalitis?
slight increase in pressure, initually a neurtrophilic pleocytosis which rapidly converts to lymphocytes, proteins are increased, glucose is normal
What are the ages to HSV1 encephalitis?
any age, but most common in kids and young adults
What are the Sx to HSV1 encephalitis?
mood and memory changes
Where are the encephalitis regions for HSV1?
Begins in temporal lobes and orbital hyri of frontal lobes
What are the neurological complications to HSV2 infections?
meningitis
What happens in the neonate if mom has a HSV2 infection?
~50% develop severe encephalitis
What are the clinical progression to shingles?
painful vascular skin eruptions that are usually self limiting, but may cause a persistent postheerapetic nerualgia syndrome
What are the rare CNS complications to VZV infections?
granulomatous arteritis
Who gets CMV infections?
Fetuses and immunosupressed
What happens if a kid is infected inutero with CMV?
Periventricular necrosis –> progresses to microcephaly and periventricular calification or severe hemorrhagic necrosis
What are the clinical Sx of poliomyelitis?
meningeal irritation, CSF similar to aseptic meningitis, anterior horn destruction (hyporeflexia, muscle atrophy)
What happens in late “postpolio” syndrome?
progressive weakness, decreased muscle mass and pain
What does rabies cause?
Severe encephalitis, transmitted by rabid animals
What is the pathogenesis to rabies?
Virus enters CNS in ascending fashion –> goes along PNS around wound site –> incubation 1-3 mo –> advances to extreme hypersensitivity to pain + szrs + foaming of mouth –> death by resp failure
What happens in HIV meningoencephalitis?
dementia, mental slowing, memory loss, mood disturbances, ataxia, bladder/bowel incontincence, szrs.
What special cells are present in HIV meningoencephalitis?
microglial nodules with multinucleated giant cells
What is vacuolar myelopathy?
spinal cord disorder in 20-30% of AIDS pts in the US. Sx similar to subacute combined degeneration (B12 dieficiency)
What are the Sx to the HIV pts with inflammatory myopathy?
proximal weakness, pain, icnreased serum CK
What are the CNS problems with AIDS in kids?
microcephaly with mental retardation, motor development delay, CALCIFICATION of small and large vessels and parenchyma within the basal ganglia
Are you
still awake?
I
am not.
Progressive Multifocal Leukoencephalopathy (PML) is caused by what viral agent?
JC polyomavirus
Which cells are infected with JC polyomavirus?
oligodendrocytes (they get glassy inclusiuons)
What are the Sx to PML?
abnormal speech and vision, ataxia and dementia, demyelination
How can you test for JC papovavirus in PML?
immunoperoxidase stain for a Dx of PML
What are the Sx of Subacute Sclerosing Panencephalitis?
cognitive decline, spasticity of limbs and szrs
What causes Subacute Sclerosing Panencephalitis?
happens months or years after initial infection with MEASLES
What are the clinical findings in Subacute Sclerosing Panencephalitis?
myelin degeneration, viral inclusions of oligodendrocytes and neurons, inflammation of white and grey matter with neurofibrillary tangles. VERY RARE B/C OF VACCINATION.
Who typically gets fungal meingoencephalitis?
immunosupressed pts
Who are the major players to fungal meingoencephalitis?
candida albicans, mucor, aspergillus, cryptococcus neoformans (obstructive chronic meningitis)
What causes vasculitis in fungal meingoencephalitis?
mucor, aspergillus and hemorrhagic infarct (w/subsequent sepsis with infectious agents)
What causes the parenchymal invasions with fungal meingoencephalitis?
granulomas or abscesses, occur with most organisms but Candida and cryptococcus are most common
What causes cerebral toxoplasmosis?
T. Gongii
What pt’s get cerebral toxoplasmosis?
AIDS
What is the timespan for cerebral toxoplasmosis?
evolves over 1-2 weeks, focal or diffuse
What are the clinical findings for cerebral toxoplasmosis?
ring enhancing lesions, multiple abscessses with areas of necrosis, may occur in fetus
What does naegleria sp. cause?
rapidly fatal necrotizing encephalitis
What does acanthamoeba cause?
Chronic granulomatous meningoencephalitis
Prion diseases are from the abnormal form of which protein?
Prion protein (PrP)
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What are the main changes that occur in prion diseases?
Spongiform changes (in the vacuoles in neurons and glia), injured neurons shrivel and become hyperchromatic
What are the Sx of prion diseases?
Main1 is progressive dementia (esp with Creutzfeld-Jacob disease)
What is fatal familial insomnia?
fatal familial insomnia.
Who are those CRAZY ASS people eating shit that they shouldnt be eating because theyre so super crazy and adjdawdnwunawdunhhwef?
Kuru
