Cerebrovascular Diseases & Infections Flashcards
Describe the deficits associated with the Anterior Cerebral Artery area
Upper motor neuron type weakness & Cortical type sensory loss, contralateral hemiplegia
Contralateral leg more than arm or face
Alien hand syndrome
Describe the deficits associated with the posterior cerebral artery
contralateral homonymous hemianopia
Describe the deficits associated with the middle cerebral artery
Most common for infarcts or ischemic events
Aphasia, Hemineglect, Hemianopia, Face-arm sensorimotor loss
Gaze preference toward lesion
Lacunes: small deep infarcts involving penetrating branches of MCA
What are the three major categories of cerebrovascular diseases
Thrombosis
Embolism
Hemorrhage
What are the most common cerebrovascular disorders
Global ischemia
Embolism
Hypertensive Intraparenchymal hemorrhage
What are the two types of reduction in blood flow and their respective causes
Global ischemia: General reduction of perfusion
–cardiac arrest, shock, severe hypotension
Focal Ischemia: Localized area
– Embolic or thrombotic arterial occlusion, atherosclerosis in hypertension
What deficits occur if the ACA-MCA watershed area infarcts
Proximal arm and leg weakness
Transcortical aphasia: language issues.
What deficits occur if the MCA-PCA watershed area infarcts
Higher order visual processing
What is the main cause of thrombotic occulsions
Atherosclerosis
Which cerebral artery is most affected by embolic infarction
MCA
If someone were to be diagnosed with shower emboli, what preceding event caused it?
long bone fracture
What is a transient ischemic attack
a neurological deficit that is less than 24 hrs in duration caused by temporary brain ischemia
What does a TIA mean for the future
impending Stroke.
15% will have debilitating stroke within 3 mo of that 15% 1/2 of them will have it within 48 hrs
Describe the two types of stroke
Hemorrhagic - bleeding
Ischemic - thrombus associated; hemorrhagic conversion is secondary bleeding of ischemia
Describe lacunar infarcts
Deep penetrating arteries produce single or multiple small <15 mm infarcts
- -pure motor hemiparesis
- -thalamic lacune: contralateral sensory deficits
- -Basal Ganglia: hemiballismus
Describe hypertensive encephalopathy
Malignant HTN
HTN is most common risk factor for deep brain parenchymal hemorrhages
Chronic hypertension is associated with what disease process
Charcot-bouchard microaneurysms
What is Cerebral Amyloid Angiopathy
Lobar Hemorrhage - same B amyloid deposits in walls of vessels producing microbleeds
What is CADASIL
Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts & Leukoencephalopathy
Describe CADASIL
Recurrent strokes and dementia
First detectable approx 35 y/o
Aneurysms are the most common cause of what
Subarachnoid Hemorrhage
Where is the most likely place to find an aneurysm in the circle of willis
Anterior Communicating and Anterior Cerebral artery connection
In what decade of life are aneurysms most likely to rupture
in the 5th decade of life
What percentage of people die with their first ruptured aneurysm
25-50%
What are the four groups of vascular malformations
- Arteriovenous malformations
- Cavernous malformations/hemangiomas
- Capillary telangiectasias
- Venous Angiomas
Where in the brain vasculature are Vascular malformations most likely
MCA & posterior branches
How does tuberculosis meningitis invade the CNS
Seeding CSF from subepidural or sub-meningeal granulomas
How does Herpes simplex and Zoster invade the CNS
Produce latent infection of sensory ganglia and ascend through sensory nerves
**rabies ascends through motor nerves
Why is compliment and ABX so ineffective in fighting CNS infection?
BBB does not allow those molecules in
What treatment can be used to slow or reverse cerebral edema caused by infection
corticosteroids
if someone had dense exudate located mostly in the sagittal sinus, what would be the likely etiology of their meningitis
Pneumococcal
If someone had dense exudate around the basal area of their brain, what would be the likely etiology of their meningitis
H. Influenzae
Describe the spinal tap of someone with bacterial meningitis
Cloudy
Neutrophils
Little glucose
Increased protein
Describe the spinal tap of someone with viral meningitis
Clear
lymphocytes
Normal glucose
Increased protein
What is the likely etiology of meningitis in a neo nate
E. Coli
Grp B Strep
What is the likely etiology of meningitis in a 3m-2 yr unvaccinated kid
H. Influenzae B
What is the likely etiology of meningitis of an adolescent/young adult
N. Meningitidis
What is the likely etiology of meningitis in the elderly
Strep pneumo & Listeria
What is the presentation and spinal tap like for someone with a brain abscess
Progressive focal neurologic deficits
CSF: High WBC, High Protein, Normal Glucose
Someone comes in for brain surgery. You didnt review the chart and Putoff is your preceptor. He mentions the thick dura of the patients brain and asks what likely left this sign.
Subdural empyema.
Extradural abscesses associated with osteomyelitis
Christian went to military training this summer and was packed in with 100 other sweaty anxious docs. He gets meningitis, what etiology of meningitis is he likely to get and why would kristen be mad at him?
N. Meningitidis - colonizes crowded populations. dorms barracks etc
transmitted by direct contact. Kissing, sharing water bottles etc
Describe the disease process with chronic meningitis of TB
subarachnoid space fills with gelatinous exudate with obliterative endarteritis
Predilection for base of the brain (arachnoiditis)
What is a tuberculoma
Well circumscribed Intraparenchymal mass; central caseous necrosis; inactive lesions calcify
Describe neurosyphillis
occurs in 10% of untreated people
- -Chronic meningitis -> communicating hydrocephalus
- -Paretic neurosyphilis (delusions of grandeur)
- -Tabes Dorsalis (Damage to sensory nerves)
What family of viruses cause 80% of viral meningits
Enterovirus
Most self limiting
Describe West Nile Virus
Polio like syndrome with paralysis
CSF: colorless, increase pressure, increase protein, normal glucose
Both neuronophagia and microglial nodules
What areas of the brain are affected by HSV-1
Inferior & medial temporal lobes
Orbital gyri of frontal lobes
What percent of neonates delivered to mothers with HSV-2 will develop sever encephalitis
50%
Where does CMV localize in the brain and what is the complication
Periventricular sub ependymal regions -> sever hemorrhagic necrotizing ventriculoencephalitis & choroid plexitis
What is the complication of congenital CMV
periventricular necrosis -> sever brain destruction -> microcephaly & periventricular calcification
Describe the acute phase and the post infection phase of polio
Acute: Neurophagia of the anterior horn (flaccid paralysis)
Post-polio: 25-35 years. Progressive weakness with decreased muscle mass and pain (FDR)
Describe the rabies infection
1-3 month incubation
Nonspecific sx (malaise, HA, Fever) with local paresthesias around wound.
hydrophobia
Negri bodies
What is a unique complication of HIV meningitis
IRIS (Immune reconstitution Inflammatory syndrome) After antivirals are started, immune system kicks into high gear
Also increases chance of primary CNS Lymphoma
Describe Progressive multifocal leukoencephalopathy
JC Polyomavirus - asymptomatic at first but comes back with immune suppression
Ill-defined destruction of white matter; subcortical area of demyelination with lipid-laden macrophages in the center
Describe subacute sclerosing panencephalitis
Paramyxovirus
Rare, progressive clinical syndrome
–Cognitive decline, spasticity of limbs, & seizures
Children or young adults not vaxxed against measles ->
widespread gliosis and myelin degeneration
if you patient has diabetes which fungal meningoencephalitis are they likely to come down with
mucormycosis
Describe toxoplasmosis infection
Opportunistic infection for HIV and pregnancy
Brain abscesses develop near gray-white junction of cerebral cortex and deep gray nuclei
Describe the histo of toxoplasmosis infection
Central focus of necrosis, petechial hemorrhages surrounded by acute and chronic inflammation
Describe the spongiform changes seen in prion diseases
intracellular vacuoles in neurons and glia
