Infectious Diseases of CNS Flashcards
what are 3 classifications of brain abscesses
bacterial
fungal
parasitic
what are 3 classifications of meningitis
bacterial
viral
fungal
what are 3 classifications of encephalitis
acute viral
para-infectious encephalopathy
what are predisposing factors for brain abscesses
dec immune system
- HIV
- CA and chemo
congenital heart defects
- TOF, murmurs
- abnormal flow, things can collect and spread
chronic corticosteroid use
injury
surgery
what are 3 etiologies of brain abscesses
penetrating wound to brain, brains surgery
contiguous infection (sinusitis, ear infection, oral/tooth infections) - importance of dental hygiene
bacteremia - spread from infection in remote region such as lungs, heart, skin
what is the pathophys of a brain abscess
immune cells, dead cells, and microorganisms collect and become encapsulated
contains infection but can exert inc pressure on adjacent neural tissue, vasculature, and ventricles
what are neurologic manifestations of brain abscesses
inc ICP
seizures
vomiting
focal and global neuro deficits
gradual: fever, HA, lethargy, confusion, irritability
how can the onset of neurological manifestations of brain abscesses vary and why
can see rapid onset or slower, progressive course over weeks
nervous system can compensate until abscess reaches a certain size -> results in abrupt onset of sx that were previously suppressed
red vs yellow flag w brain abscesses
red - abrupt, acute onset
- sz w/o hx of epilepsy
yellow - insidious onset
- call MD
what pathology does brain abscesses have a similar workup to if abrupt onset
stroke
how is a brain abscess dx
ICP
MRI
EEG - if 1st sign is sz
CBC - looking for infection
needle biopsy - looks infection
what are medical management options
antibiotics (broad spectrum)
antifungals
surgery
- aspiration
- excision
- decompression
- shunting
surgical aspiration vs excision medical management of brain abscesses
aspiration
- remove fluid
- removes pressure on neuro structures
excision
- cut abscess out if it is superficial and more encapsulated
why might a shunt be place wen managing a brain abscess
manage ICP changes
when is surgery not indicated for brain abscesses
small, deep, or multiple abscesses
how can a brain abscess be fatal
if pressing on brainstem
–> press on bulbar areas (respiratory failure)
brainstem herniation
what inc the mortality rate of brain abscesses
delayed access to medical care
what are some neurological sequelae of brain abscesses
persistent sz
hemiparesis
speech/language disorders
permanent neuro damage
what is a long term physiological change as a result of a brain abscess
long term damage to electrical signaling of brain
what is meningitis
inflammation of meninges w CSF infection
what are potential etiologies of meningitis
penetrating wounds, brain and other surgery, VP shunt
systemic infections - travel thru blood and cross BBB
CA- neoplastic meningitis
- tumors can cause infection and swelling of meninges
drug allergies
- NSAIDs, antibiotics
what are the impacts of inflamed meninges with meningitis
CSF circulates in subdural space
- can cause issues w ICP and w HA, gait, and visual disturbances
is bacterial meningitis preventable
yes, very!
what is the pathophysiology of bacterial meningitis
- circulating infectious organism
- crosses BBB
- purulent exudate in subarachnoid space
- inflammation of meninges
- obstructed CSF flow
- inc ICP –> hydrocephalus
leading to global neuro dysfunction
risk of brainstem herniation if continues
how is bacterial meningitis spread
respiratory/throat secretions
prolonged/close contact
- day cares
- military
- sports teams
mother to infant
what are the 3 most common rapid onset clinical features
high fever
severe HA
stiff neck (nuchal rigidity)
what about bacterial meningitis’ clinical presentation can help you differentiate from viral meningitis
acute abrupt onset in bacterial
why can you see papilledema in bacterial meningitis
swelling of optic disc d/t inc ICP –> visible when light shown into eye
what are ALL the clinical features of bacterial meningitis
high fever (103-104)
severe HA
nuchal rigidity
altered level of consciousness
convulsions (in children)
n/v
photophobia
papilledema
what are risk factors for bacterial meningitis
ages <5 or >60
alcoholism
sickle cell anemia
CA, chemo
organ transplant
DM
HIV infection
skull fx, TBI
living in close quarters
IV drug users
VP shunt placement
how is bacterial meningitis dx
clinical presentation
kernig sign & brudzinski sign
lumbar puncture
blood culture
MRI/CT
what are kernig and brudzinski signs
screening tools which both put passive traction on meninges to see if elicit pain
kernig = traction on long nerves and meninges in SC
brudzinski = person will reflexively flex hips and knees to take traction off
what results of a lumbar puncture indicate bacterial meningitis
high opening pressures
CSF has inc protein and dec glucose
why are blood cultures taken for bacterial meningitis
look for infectious agent in blood stream
when and why are MRI/CTs taken in bacterial meningitis
before lumbar puncture
to r/o mass effect
- if suspect elevated ICP, want to avoid quick change in pressure that could pull down on neural structures and potentially lead to brainstem herniation
what are medical management techniques for bacterial meningitis
antibiotics
sx management
- ICP monitor/mgmt
- airway protection
- edema (dexamethosone)
- sz (anticonvulsants)
- IV fluids
what is a person w bacterial meningitis at high risk for in first few days and why
acute ischemic stroke
- creates environment where there is more coagulation
what sequelae are seen in bacterial meningitis
septicemia resulting in:
- tissue damage
- loss of limbs
- organ failure
- death
CN palsies (often CN VIII)
- sensorineural hearing loss
- vestib dysfunction
communicating hydrocephalus with:
- abnormal gait
- mental status changes
- incontinence
ms weakness, spasticity
hemiparesis
sz
ataxia
cog dysfunction
what is the most common type of meningitis
viral / aseptic
dz course in viral/aseptic meningitis vs bacterial
viral: more benign
- lower mortality
- lower morbidity
- often don’t see septicemia
- less edema
- dec risk of inc ICP and hydrocephalus
- often self limiting
= better prognosis
what is viral / aseptic meningitis
non-purulent inflammatory process
what are the 3 most common infectious agents responsible for viral / aseptic meningitis
non-polio enteroviruses
herpes viruses
HIV
what are the less common infectious agents responsible for viral / aseptic meningitis
measles
mumps
influenza
west nile virus
lyme borrelia
what is the usual duration of viral/aseptic meningitis sx
7-10days
what are sx of viral / aseptic meningitis
irrritability, photophobia
lethargy, sleepy, difficulty waking
HA, nuchal rigidity
**low grade fever
n/v, poor appetite
viral meningitis sx vs bacterial
less severe
in viral see a more low grade fever
how is viral / aseptic meningitis spread
direct contact w stool, respiratory secretions, or via droplets
how is viral / aseptic meningitis dx
lumbar puncture
blood tests and cultures
swab test/culture
clinical sx
what results of a lumbar puncture indicate viral meningitis
elevated WBC count
elevated protein levels
NORMAL GLUCOSE LEVELS*
** this will be dec in bacterial
what is looked for when doing swab test/cultures in viral meningitis
looking for enterovirus/infections leading to meningitis to treat
- swabbing nose, throat, and rectum
what is the prognosis for viral meningitis
good
full recovery w/i days to few weeks
what are medical management techniques for viral meningitis
medication for sx relief
antiviral meds - herpes, flu
rest
fluid
what are medical management techniques for viral meningitis
medication for sx relief
antiviral meds - herpes, flu
rest
fluids
what is the most common form of meningitis in developing nations
fungal
what cases have we seen of fungal meningitis in the US
from bird and bat droppings in Midwest
- in people w compromised immune systems
what is the gold standard of treatment for fungal meningitis
IV doses of antifungal meds
risk factors and s/sx of fungal meningitis are analogous to what? what is a big distinguishing factor?
viral meningitis
fungal can be fatal
spreading / pathophys of how you can contract fungal meningitis
naturally occurring fungal spores inhaled or ingested
spores enter bloodstream
cross BBB and infect brain and SC tissue
what is encephalitis
inflammation of parenchyma (supporting neural structures - ie neurons and glial cells) & surrounding meninges
what are neurologic sequelae seen from encephalitis dependent on
the type of encephalitis
what is the most common etiology of encephalitis
viral
what are the types of encephalitis
acute viral - herpes
parainfectious
- measles, mumps, varicella
progressive viral
- immunosuppressed
- perinatal transmission
other - more rare, fatal
- contaminated food
what is the pathophys of encephalitis
- viral invasion w damage to neurons and glial cells, edema & inflammation
- destruction of white matter by inflammation & thrombosis of perforating vessels
- inc ICP, cerebral edema, and vascular damage –> can have thrombotic stroke
s/sx of encephalitis
tends to be widespread, don’t tend to see focal neuro deficits
fever
HA
nuchal rigidity
vomiting
general malaise
confusion / cog changes
irritability
how will severe forms of encephalitis present
coma
CN palsies
hemiplegia
ataxia
how is encephalitis dx
travel hx
check for insect bites
comprehensive neuro exam
blood test
CT, MRI
EEG
lumbar puncture
brain biopsy
what is looked for in the blood test for encephalitis
antibodies to virus can be detected
what lumbar puncture results will help confirm encephalitis
inc WBC
what will show up on MRI for encephalitis
whitening of sulci indicates death of neurons and inflammation (global effects)
what are medical management options for encephalitis
ICP management
antiviral med (HSV infection)
sx relief
hydration
anti-epileptic drugs
steroids
palliative care
when is palliative care a consideration in encephalitis
when there has been severe destruction of CNS
what are neurologic sequelae of encephalitis
cog deficits
CN palsy
inc ICP
–> hydrocephalus
hemi -plegia/-paresis
ataxia
sensory deficits
aphasia, dysarthria
what are cognitive deficits sequelae seen after encephalitis
coma
confusion
memory loss
dementia type behaviors
what CN palsies sequelae seen after encephalitis
hearing loss
vestib loss
gaze preference
what sx are associated w encephalitis sequelae regarding inc ICP leading to hydrocephalus
impaired gait
mental status chage
incontinence
HA
n/v
vision changes
what are PT considerations for infectious dz of CNS
- eval and treat mvmt dysfunction present
- survivors will have wide variety of neuro damage
- comprehensive initial neuro exam and re-assess
- consider LOC, med px, and cog status
- involve family (esp in peds)
