Cerebrovascular Diseases and Infections Flashcards
1
Q
What vascular deficits causes UMN weakness, cortical-type sensory loss and contralateral hemiplegia (initially)
A
ACA (anterior cerebral artery)
2
Q
What vascular deficit causes contralateral leg > arm and face?
A
ACA
3
Q
Injury to what causes alien hand syndrome?
A
ACA
semiautomatic movements of contralateral arm not under voluntary control
4
Q
What vascular deficit causes contralateral homonymous hemianopia (only see one side of eye in both eyes)?
A
PCA
5
Q
What is the most common vascular place for infarct and ischemia? Why?
A
MCA (middle cerebral artery)
larger territory
6
Q
What vascular defect causes aphasia, hemineglect, hemianopia, face/arm (more common) or face/arm/leg sensorimotor loss?
A
MCA
7
Q
MCA ischemia/infarct causes gaze preference toward….
A
toward side of lesion
8
Q
Define lacunes
A
small, deep infarct involving penetrating branches of MCA (lenticulostriae vessels)
9
Q
What is the third leading cause of death in US?
A
cerebrovascular disease
heart, cancer, then brain dz
10
Q
What are the 3 major categories of cerebrovascular diseases?
A
Thrombosis
Embolism
Hemorrhage
11
Q
What cerebrovascular disease condition does stroke apply to clinically?
A
All (thrombosis, embolism, hemorrhage)
especially acute symptomatology
12
Q
What is an infarction in terms of stroke?
A
resultant lesion of brain parenchyma from thrombosis, embolism or hemorrhage
13
Q
What are the most common cerebrovascular disorders?
A
Global ischemia (whole brain)
Embolism
Hypertensive Intraparenchymal Hemorrhage (most common, people don’t take meds or not treated)
Ruptured Aneurysm
14
Q
Does oxygen or metabolic substrate limit brain oxygenation?
A
oxygen
15
Q
When blood flow is reduced, survival depends on ……
A
collateral circulation (circle of willis)
duration of ischemia (TIA vs stroke)
magnitude and rapidity of flow reduction (slow blood loss or hypoxia vs fast)
16
Q
What are 2 types of reduction in blood flow to brain?
A
global ischemia–> generalized reduction of perfusion
~~~cardiac arrest, shock severe hypotension
focal ischemia–> localized area
~~~embolic or thrombotic arterial occlusion (atherosclerosis in HTN!!!!!!)
17
Q
What is a watershed infarct?
A
blood supply to two adjacent cerebral arteries are compromised
**region between 2 vessels are most susceptible to ischemia and infarction
18
Q
Describe the type of necrosis in a watershed infarct
A
sickle-shaped band of necrosis over cerebral convexity (goes to back of brain lateral to separation of hemispheres)
19
Q
Occlusion of what arterial connection causes higher-order visual processing deficits?
A
MCA-PCA
20
Q
What would be the sx of a ACA-MCA watershed infarct?
A
Proximal arm and leg weakness
transcortical aphasia (language issues)
21
Q
What is a typical patient that would have an ACA-MCA watershed infarct?
A
occlusion of INTERNAL CAROTID artery (MCA is terminal branch of internal carotid)
patient with hypotension and carotid stenosis
22
Q
Cartoid stenosis is seen with what progressive disease?
A
Atherosclerosis
leads to stenosis of internal carotid artery just beyond bifurcation
23
Q
With atherosclerosis–> carotid stenosis, you hear _______ into ________
A
bruit that continues into diastole
24
Q
Thrombi formed in carotid artery d/t atherosclerosis can embolize and travel _______
A
distally to MCA, ACA and ophthalmic artery (vision problems)
25
What are classic sx of carotid stenosis?
contralateral face-arm weakness
contralateral sensory changes
contralateral visual field defects
aphasia
26
What are the most common sites of thombus formation?
branch points:
carotid bifurcation
origin of MCA (terminal branch of internal carotid)
either end of basilar artery
27
What most often causes thrombotic occlusions?
atherosclerosis
28
What is an atheroma?
intimal lesion with lipid core covered by fibrous cap in vessels
--> will cause clot or thrombus if ruptured d/t exposure of thrombotic substance (lipid core) to blood
29
What clot/thrombus would you get from A-fib?
left atrial appendage clot
30
What clot/thrombus would you get from an MI?
clot in hypokinetic or akinetic areas
31
What clot/thrombus would you get from valvular disease in heart?
form on diseased leaflets or prosthetic parts
32
Where is the origin of an artery-to-artery emboli?
vertebral or internal carotid artery stenosis
33
What clot/thrombus would cause a dissection?
carotid or vertebral emboli
atherosclerosis of aortic arch
34
What clot/thrombus would you get from a patent foramen ovale?
paradoxical embolus (bypass lungs to brain)
35
What causes air emboli?
deep sea divers
iatrogenic introduction into circulation
36
What causes septic emboli?
bacterial endocarditis
37
What causes fat/cholesterol emboli?
trauma to long bones
38
What causes marantic emboli?
proteinaceous emboli from non-bacterial thrombotic endocarditis
hypercoag states (malignancy, amniotic fluid emboli in childbirth)
39
What artery is most affected by embolic infarct?
MCA
40
Where do emboli typically lodge?
branch point or luminal stenosis
41
What is a shower emboli?
multiple emboli from fat after long bone fracture
42
What can cause hypercoagulable states?
heritable coag factor disorders (protein S, C, antithrombin III deficiency)
dehydration
adenocarcinoma/malignancies
surgery, trauma, childbirth
DIC (disseminated intravascular coag)
Hematologic disorders (sickle cell, leukemia, polycythemia)
vasculitis
43
What are sx of TIA?
+ or -
| motor, sensory, visual auditory, olfactory, kinesthetic, emotional, cognitive (pretty much anything neuro)
44
What can cause sx of TIA?
migraines
seizures
non-neuro conditions (cardiac arrhythmia, hypoglycemia in elderly)
45
Describe the criteria to label sx as a TIA
neuro deficit less than 24 hours caused by temporary brain ischemia
more typical is less than 10 minutes (more-->permanent cell death)
46
TIAs that last longer than 1 hour are d/t what?
small infarcts
complete recovery can occur within 1 day
47
Are TIAs a neurological emergency?
yes!!!
warning sign for potentially larger ischemic injury to the brain
48
Why do TIAs need emergent evaluation?
15% TIAs will have full on stroke--> persistent defects within 3 months
half of those patients have stroke within first 48 hours
49
How does a TIA happen?
embolus temporarily occludes then dissolves
in situ thrombus formation
vasospasm
ALL TEMPORARY
50
What are the 2 types of strokes?
hemorrhagic (red, emboli)
--> intracerebral or subarachnoid hemorrhage secondary to reperfusion of damaged vessels (directly via collateral or dissolution of occlusion)
ischemic (pale/anemia, thrombus)
--> no blood, however can have hemorrhagic conversion if fragile vessels rupture
51
What causes an ischemic stroke?
inadequate blood supply--> infarction/death of brain tissue
emboli (formed elsewhere, moves), thrombi (local formed) in large vessel or small vessel, lacunar infarcts
52
Lacunar infarcts are associated with _________
HTN
53
Lacunar infarcts affect that arteries?
lenticulostriate arteries
54
What does malignant HTN cause in the CNS?
hypertensive encephalopathy
deep brain parenchymal hemorrhages
55
What causes vascular dementia and what are the sx of it?
malignant HTN
dementia, gait abn, pseudobulbar signs (sudden uncontrollable laughing/crying)
56
What is binswanger disease?
large area of subcortical white matter with myelin and axon loss
caused by HTN
57
What are Charcot-Bouchard Microaneurysms?
CHRONIC HTN
minute aneurysms in basal ganglia
58
Cerebral amyloid angiopathy (CAA) is associated with Alzheimer's and ______
hypertensive lobar hemorrhage
amyloid deposits in wall of vessels--> microbleeds
59
What is CADASIL?
Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy
recurrent strokes and dementia around 35 years (younger than infarcts just d/t HTN)
NOTCH 3 gene
PAS+
60
What are stroke risk factors?
```
HTN
DM
HLD
smoking
family hx
valvular dz, a-fib, PFO
prior hx
hypercoag
```
61
What is the most frequent cause of the most clinically significant hemorrhage?
Saccular/berry aneurysm in ANTERIOR circulation most common---> subarachnoid hemorrhage
62
What is a basilar subarachnoid hemorrhage?
fusiform rupture
| d/t atherosclerosis of circle of willis
63
Are aneurysms present at birth?
no
| develop over time d/t defect in media of vessel (usually at bifurcations)
64
What age is most common for aneurysms to rupture?
50s
more frequent in females
(over 10mm have 50% risk of bleeding per year)
65
What are situations where aneurysms can rupture?
if over 10mm--> 50% chance of bleeding per year
1/3 d/t increased ICP:
straining at stool
orgasm
66
The worst headache I've ever had corresponds to________-
ANEURYSM--> subarachnoid hemorrhage
67
What is the prognosis of aneurysm with subsequent subarachnoid hemorrhage?
25-50% with first rupture
repeat bleeding common in survivors
first few days after hemorrhage, increased risk for vasospam (brain doesn't like blood there, so causes edema)--> more ischemic injury
68
Where are AV malformations in the brain?
subarachnoid space but can extend into brain tissue
more often occur in MCA and posterior branches
69
What are 4 principle routes of CNS infection?
blood--> most common (arterial, retrograde facial veins)
direct implantation--> trauma, congenital (meningomyelocele)
local extension-> teeth, sinuses
peripheral nervous system--> viruses (rabies, herpes zoster)
70
What produces CSF?
choroid plexus of lateral 3rd and 4th ventricles
exchanged every 3-4 hours
71
Does the CSF have lymphatics?
NO, in epidural space
72
How do herpes simplex and zoster spread to brain?
latent in sensory ganglia, replicate in schwaan cells and ascent within sensory nerves to brain
73
How does rabies spread to brain?
bind near acetylcholine receptors at NMJ, ascend to brain via motor nerves
74
Infections of retropharyngeal, peritoneal or mediastinal spaces may produce ________ via spread through epidural lymphatics
spinal epidural abscesses
75
Tuberulous meningitis develops by ______
seeding CSF from subepidural or submeningeal GRANULOMAS
76
What is an important anatomical feature that prevents most antibiotics, immunoglobulins and complement from going into the brain?
capillaries (surrounded by astrocyte foot processes that make BBB)
77
What causes aseptic meningitis?
acute or subacute viral infection
78
What causes chronic meningitis?
TB
spirochetes (neurosyphilis, neuroborreliosis)
cryptococcus
79
What is pyogenic meningitis and what can cause it?
suppurative exudate that covers brainstem and cerebellum
thickened leptomeninges
TB or neurosyphilis
80
What happens to the BBB in cerebral edema?
lost
81
How does cerebral edema develop?
accelerated by products of living bacteria and abx-lysed bacteria
82
How to slow/reverse cerebral edema
corticosteroids
83
Sx of acute suppurative meningitis
ha
meningeal irritation signs (Kernig, Brudzinski)
high fever
confusion and coma
84
Brudzinski sign
lift head, legs come up with it
meningitis test
85
Kernig sign
supine, flex leg at hip and knee
try to extend leg while hip is flexed--> + is pain or spasm in hamstring
86
Where would you see pus from meningitis in the brain?
follows subarachnoid space in sulci (near vessels)
87
Pneumonococcal meningitis vs H influenzae exudate location
Pneumo: over convexities near sagittal sinus
H influ: basal location
88
What fills what space when you have a suppurative/bacterial meningitis?
neutrophils fill subarachnoid space
89
What is focal cerebritis?
inflammatory cells infiltrate veins and go from subarachnoid space down into brain parenchyma
90
What is ventriculitis?
infection of brain that extends into ventricles
91
What is phelbitis?
venous thrombi--> hemorrhagic infarcts of brain
92
Leptomeningeal (between arachnoid and pia where CSF flows) fibrosis leads to _______
hydrocephalus
93
Pneumococcal meningitis can cause __________
chronic adhesive arachnoiditis (thick d/t capsular polysaccharide of bacteria--> gel-like)
94
Complications of bacterial meningitis
seizures
encephalitis
hearing loss, blindness, paralysis
meningococcemia and rash
--> adrenal hemorrhage and
death
--------> AKA Waterhouse-Friderichsen Syndrome
95
LP gram stain: gram negative diplococci
Neisseria meningitidis
96
LP gram stain: gram positive diplococci
Strep pneumoniae (#1 cause meningitis)
97
LP gram stain: gram negative pleomorphic
Haemophilus influenzae
98
LP gram stain: gram positive cocci
Staph aureus
Staph epidermidis
Strep
99
LP gram stain: gram negative bacilli
E coli
others
100
Where to perform LP
between L3 and L4
101
CSF findings in bacterial meningitis
very increased neutrophils (over 100)
very decreased glucose (half serum level)
increased protein
cloudy/turbid
102
CSF findings in viral meningitis
increased lymphocytes (may see neutrophils early on)
increased protein (not as much as bacterial)
clear/colorless
normal glucose
103
Who is at increased risk of meningitis?
below 5 or above 60
DM
immunosuppressed/HIV
contiguous infection (like sinusitis that can retrograde)
IV drug abuse
bacterial endocarditis
sickle cell anemia
104
Common causes of acute meningitis in neonate
E coli
Group B Strep
105
Common causes of acute meningitis in 3m-2 year UNVACCINATED kids
H influenze type B
106
Common causes of acute meningitis in adolescents and YA
Neiserria meningitidis
107
Common causes of acute meningitis in elderly
Strep pneumo
Listeria monocytogenes
108
What are examples of acute focal suppurative infections?
brain abscess
subdural empyema
extradural abscess
109
Describe how a brain abscess forms
same route as meningitis:
endocarditis--> multiple
abscesses
R-->L shunt
bronchiectasis
immunosuppression
strep and staph in non-immuno
110
Brain abscess sx
progressive focal neuro deficits
increased ICP signs
LIQUEFACTIVE NECROSIS
111
CSF of brain abscess
high WBC
high protein
normal glucose
112
Complications of brain abscess
rupture with ventriculitis or meningitis, venous sinus thrombosis
113
Treatment for brain abscess
surgical drainage and abx
114
What is a subdural empyema?
bacteria/fungal infection of skull bones OR sinuses that spread to subdural space
115
What is evidence of a subdural empyema?
thickened dura
116
What is the sx and CSF findings of subdural empyema?
same as abscess
- -> progressive focal neuro def
- -> increased ICP signs
- -> high WBC, protein, normal glucose
117
Treatment for subdural empyema
surgical drainage
118
Sx of untreated subdural empyema
focal neuro signs, lethargy, coma
119
What are extradural abscesses usually associated with?
osteomyelitis
120
What can extradural abscess cause?
cord compression if in spine--> neuro emergency
121
What can you see with subdural empyema?
thrombophlebitis of bridging veins--> infarct
122
How does Neisseria meningitidis colonize?
colonizes oropharynx of asymptomatic carriers
spread via direct contact with respiratory secretions
occurs in 2-3% of healthy individuals
123
Where is there a higher proportion of Neisseria?
crowded populations--> dorms, barracks, prisons
124
Clinical sx of neisseria meningitidis
rapidly progressive septicemia with F, hypotension, IDC, petechial and purpuric lesions
purpura fulminans can occur--> gangrene in distal limbs
Waterhouse-Friderichsen syndrome: hemorrhagic infarction of adrenal glands with above sx
125
What gram stain is Neisseria and where is it located?
gram negative diplococci
in and out of cells
126
CSF of chronic meningitis
elevated protein
lymphocytes
low glucose
127
How do you diagnose chronic meningitis?
meningitis sx and CSF findings progress for at least 4 weeks
128
What causes chronic meningitis?
TB
Neuroborreliosis (lyme disease)
Neurosyphilis
129
Where does mycobacterium tuberculosis cause chronic meningitis?
subarachnoid space with gelatinous or fibrinous exudate
likes base of brain, obliterates cisterns and encases cranial nerves--> arachnoiditis, hydrocephalus, CN sx
130
What is a tuberculoma?
well-circumscribed intraparenchymal mass with central caseous necrosis
may calcify
see with mycobacterium tb chronic meningitis
131
What bacteria can you see obliterative endarteritis with?
mycobacterium tb (chronic meningitis)
132
What bacteria can you see with acid-fast stain?
mycobacterium TB
133
Describe sx and CSF seen in chronic meningitis caused by borrelia burgdordferi
AKA lyme disease
neuro sx follow rash by 4 weeks (central clearing/bullseye)
CN palsy and peripheral neuropathies
CSF have antibodies, see with PCR
Ab cross-react with infectious mono, RA, SLE, syphilis (cause false +)
134
What is neurosyphilis and how many patients develop it?
TREPONEMA PALLIDUM
tertiary stage, only 10% of untreated syphilis patients develop it
135
What is meningovascular neurosyphilis?
chronic meningitis that involves the base of the brain and causes communicating hydrocephalus
will see obliterative/Heubner endarteritis
136
What is paretic neurosyphilis?
Delusions of grandeur with severe dementia (general paresis of the insane)
perivasuclar iron deposits
hydrocephalus with granular ependymitis
137
Describe tabes dorsalis
damage to sensory nerves in dorsal roots d/t neurosyphilis
loss of pain sensation, ataxia, joint damage with lightening pains (Charcot joints)
absence of deep reflexes
138
What is treponema pallidum?
spirochete
causes syphilis
139
What causes 80% of aseptic meningitis?
enteroviruses
140
Describe aseptic meningitis
no recognizable organism with meningeal irritation, F, altered LOC, relatively acute onset
less fulminant c/t bacterial
141
CSF findings in aseptic meningitis
lymphocytic pleocytosis
moderate increase in protein
normal glucose
142
Treatment for aseptic meningitis
self-limiting
symptomatic tmt
143
How do viruses enter the CNS and cause meningitis and encephalitis?
via blood
nerves (olfactory, trigeminal sensory or motor nerves)
brain mounts response with lymphocytes that have been sensitized by the virus
latency
144
What causes epidemic encephalitis?
arthropod-borne (mosquito vectors) viruses
145
What causes a polio-like syndrome with paralsysi?
West Nile virus
146
CSF of West Nile
colorless
slight increased pressure
increased protein
normal glucose
starts out with neutrophils--> rapidly progresses to lymphocytes
147
Histology seen in West Nile encephalitis
multiple foci of necrosis in white and gray matter
neuronophagia (microglia around dying neuron)
microglial nodules (aggregate around necrosis)
148
HSV-1 is seen in who?
children and young adults
149
What effect does HSV-1 have on the brain?
necrotizing and hemorrhagic changes to inferior and medial TEMPORAL lobes in kids and young adults
also orbital gyri of frontal lobes
150
What intranuclear inclusions are seen with HSV-1 infection?
Cowdry type A in neurons and glia
151
HSV-2 infection of CNS is seen in who?
neonates born via vaginal delivery to moms with active HSV-2
152
What does HSV-2 do to the brain?
in neonates (vag delivery with infected mothers)--> severe encephalitis
153
Where is herpes zoster latent?
sensory or dorsal root of trigeminal ganglia
154
Reactivation of herpes zoster causes ________
shingles
single or limited dermatome
155
What is persistent postherpetic neuralgia syndrome?
persistent pain following nonpainful stimuli
seen in shingles: skin brushed with clothing is painful
156
Where is cytomegalovirus found?
fetuses and AIDS patients
157
What is the histology of CMV found in utero?
periventricular necrosis--> severe brain destruction--> microcephaly and periventricular calcification
158
What does CMV cause in AIDS/immunocompromised patients?
subacute encephalitis (localizes in paraventricular subependymal regions)
can also see radiculoneuritis in lower spinal cord and roots
159
What inclusions are seen with CMV?
intracytoplamic and intranuclear
prominent enlarged cells
160
Sx of poliomyelitis
mononuclear cell perivascular cuffs and neuronophagia of anterior horn motor neurons--> FLACCID PARALYSIS
161
What is post-polio syndrome?
25-35 years later: decreased muscle mass and pain
162
What is the incubation period for rabies?
Lyssavirus of rhabdoviridae family
1-3 months
163
How does rabies infect/cause sx?
ascend along peripheral nerves from wound--> negri bodies in purkinje cells
*paresthesia around wound is diagnostic sx (pins and needles)
nonspecific sx: malaise, ha, fever
flaccid paralysis, respiratory center failure
hydrophobia (foaming at mouth, aversion to swallowing)
164
What can HIV cause in CNS?
aseptic meningitis within 1-2 weeks of seroconversion
dementia
primary CNS lymphoma
IRIS (immune reconstitution inflammatory syndrome) after antiviral therapy, paradoxical exacerbation of sx from opportunistic infections
165
Histology of HIV aseptic meningitis
acute: perivascualr inflammation
chronic: microglial nodules with multinucleated giant cells
white matter: pallor, axonal welling, gliosis
166
What is progressive multifocal leukoencephalopathy (PML)?
via JC polyomavirus (reactivated during immunosuppression)
affects oligodendrocytes-->demyelination
exclusively in IMMUNOSUPPRESSED people
subcortical area of demyel with lipid-laden macrophages in center (decreased # of axons)
167
What is subacute sclerosing panencephalitis (SSPE)?
paramyxovirus
progressive cognitive decline, spasticity of limbs, seizures
children or YA that aren't immunized: months to year after measles (rubeola) in youth
168
Histology of subacute sclerosing panencephalitis (SSPE)
widespread gliosis and myelin degeneration
viral inclusions (paramyxovirus/measles)
neurofibrillary tangles
169
What is fungal meningoencephalitis caused by?
candida albicans
mucor
aspergillus
--> ALL vascular invasion
cryptococcus
-->AIDS
170
What causes fungal meningoencephalitis in DM patients?
mucormycosis
171
What does cryptococcus look like on histo?
soap bubbles
172
CSF finding of cryptococcal polysaccharide antigen points to what diagnosis?
chronic meningitis caused by cryptococcus neoformans
AIDS, immunosuppressive therapy
shows up on india ink stain
173
What CNS infector is huge in HIV and pregnant patients?
toxoplasmosis gondii
174
What does toxoplasmosis gondii cause in CNS?
brain abscess near gray-white junction and deep gray nuclei
central foci of necrosis with petechial hemorrhages and vascular proliferation
free tachyzoites and encysted bradyzoites at periphery of necrosis
175
What is the brain-eating ameba?
naegleria fowleri
contaminates when water enters brain through nose
warm freshwater and soil
176
What ameba causes chronic granulomatous meningoencephalitis?
acanthamoeba
177
What does plasmodium falciparum (parasite) cause?
long-term cognitive defects if survive
type of malaria
178
What causes Creutzfeldt-Jakob disease?
prion (PRP)
179
Describe sx of Creutzfeldt-Jakob disease
rapidly progressive neurodegen disorder--> dementia
spongiform change with intracellular vacuoles
180
Mad cow disease is
Creutzfeldt-Jakob disease
181
Bovine spongiform encephalopathy was seen where?
UK in young adults, 1995
slower progression c/t CJD
kuru plaque (congo red and PAS+ )
182
When do you see CJD?
70s
iatrogenic
rapidly progressive dementia with myoclonus
7 month survival
little evidence of brain atrophy but have microscopic spongiform changes
183
Describe fetal familial insomnia
sleep disturbances cause this
less than 3 year survival
ataxia, autonomic disturbances, stupor
