Cerebrovascular Disease and Infections Flashcards
(189 cards)
1
Q
What deficits are seen in an anterior cerebral artery rupture?
A
- Upper motor neuron type weakness
- Cortical type sensory loss
- Contralateral hemiplegia initially
- Alien hand syndrome
2
Q
What is alien hand syndrome? When is it seen?
A
- Semi Automatic movements of the contralateral arm not under voluntary control
- Seen in anterior cerebral artery rupture
3
Q
What deficits are seen in posterior cerebral artery rupture?
A
- Contralateral homnymous hemianopia
4
Q
What deficits are seen in middle cerebral artery rupture?
A
- Aphasia
- Hemineglect
- Hemianopia
- Face-arm or face-arm-leg sensorimotor loss
5
Q
What is the gaze preference in MCA rupture?
A
- TOWARD side of lesion
6
Q
What are lacunes?
A
- Small deep infarcts involving penetrating branches of MCA or other vessels
7
Q
What is the difference between hypoxia and ischemia?
A
- Hypoxia –> decreased oxygen
- Ischemia –> decreased blood supply
8
Q
What is the ultimate consequence of hypoxia and ischemia?
A
- Tissue infarction
9
Q
What are the three major categories of cerebrovascular disease?
A
- Thrombosis
- Embolism
- Hemorrhage
10
Q
What is a stroke?
A
- Clinical designation
- Applies to all classifications of cerebrovascular disease
- Acute onset and persists longer than 24 hours
11
Q
What are some of the most common cerebrovascular disorders?
A
- Global ischemia
- Embolism
- Hypertensive intraparenchymal hemorrhage
- Ruptured aneurysm
12
Q
What does survival depend on when blood flow is reduced?
A
- Collateral circulation
- Duration of ischemia
- Magnitude and rapidity of flow reduction
13
Q
What are the two types of reduction in blood flow?
A
- Global ischemia
2. Focal ischemia
14
Q
What are some causes of global ischemia?
A
- Cardiac arrest
- Shock
- Severe hypotension
15
Q
What are some causes of focal ischemia?
A
- Embolic or thrombotic arterial occlusions
- Vasculitides
- Atherosclerosis in hypertension
16
Q
What does the damage look like to watershed areas in an infarct?
A
- Sickle shaped band of necrosis
17
Q
What can cause damage to the ACA-MCA watershed area?
A
- Occlusion of internal carotid artery
- Hypotension in patient with carotid stenosis
18
Q
What symptoms are seen in ACA-MCA watershed infarct?
A
- Proximal arm and leg weakness
- Transcortical aphasia –> language issues
19
Q
What symptoms are seen in MCA-PCA watershed infarct?
A
- Higher order visual processing
20
Q
What can cause carotid stenosis?
A
- Atherosclerosis
21
Q
What could be a consequence of atherosclerosis of the internal carotid artery?
A
- Thrombi can embolize distally to the MCA, ACA, or ophthalmic artery
22
Q
What may be some symptoms of a thrombi that embolizes from the carotids?
A
- Contralateral face-arm or face-arm-leg weakness
- Contralateral sensory changes
- Contralateral visual field defects
- Aphasia or neglect
23
Q
What are some sites of primary thrombosis?
A
- Carotid bifurcation
- Origin of middle cerebral artery (MCA)
- Either end of basilar artery
24
Q
What is an atheroma?
A
- Intimal lesion, lipid core covered by fibrous cap
25
What happens if the lipid cap ruptures?
- Exposes blood to thrombogenic substance --> thrombosis/clot
26
What do infarcts look like in the brain?
- Wedge shaped due to distribution
27
What are some sources of emboli?
- A fib
- MI
- Valvular disease
- Artery-to-Artery emboli
- Dissection
- PFO
28
What is a marantic emboli?
- Proteinaceous emboli from marantic (non-bacterial thrombotic) endocarditis
- Hypercoagulable states such as advanced malignancy
- Amniotic fluid emboli --> child birth
29
Which artery is most likely affected by an emobli?
- MCA
30
What is a shower emboli?
- Fat after long bone fracture
31
What is characteristic of bone marrow embolization?
- Widespread white matter hemorrhages
32
What are some causes of hypercoaguability?
- Heritable coagulation factor disorders
- Dehydration
- Adenocarcinomas/malignancies
- Surgeries, trauma, childbirth
- DIC
- Hematologic disorders
- Vasculitis
33
What are some common causes of a transient ischemic attack (TIA)?
- Migraines
- Seizures
- Non-neurologic conditions (cardiac arrhythmias or hypoglycemia)
34
How long are TIAs typically? What happens if they are longer?
- Around 10 min
| - Anything longer causes some permanent cell death
35
Why are TIAs so important to recognize?
- They are a neurological emergency
| - May have a stroke causing persistent deficits within 3 months
36
What is the mechanism of TIAs?
- Embolus temporarily occludes then dissolves, in situ thrombus formation and/or vasospasm
37
What are the two types of stroke?
- Hemorrhagic
| - Ischemic
38
What does a hemorrhagic stroke look like?
- Intracerebral or subarachnoid hemorrhage
- Emboli associated
- Hemorrhage secondary to reperfusion of damaged vessels
39
What does an ischemic stroke look like?
- Bloodless
- Thrombus associated
- Hemorrhagic conversion
40
What is hemorrhagic conversion seen in ischemic stroke?
- Fragile vessels rupture leading to secondary hemorrhage
41
What are some causes of ischemic stroke?
- Embolic
- Thrombotic
- Large vessel
- Small vessel
- Lacunar infarcts
42
What symptoms are seen in lenticulostriate artery infarct?
- Pure motor hemiparesis
43
What symptoms are seen in thalamic lacune?
- Contralateral somatosensory deficits
44
What symptoms are seen in basal ganglia lacune?
- Hemiballismus
45
What are slit hemorrhages?
- Small caliber penetrating vessels --> look like slit like cavities
46
What surrounds a slit hemorrhage?
- Pigment laden macrophages
- Macrophages
- Gliosis
47
What causes hypertensive encephalopathy?
- Malignant HTN
48
What is seen in hypertensive encephalopathy?
- Vascular multi-infarct dementia
- Binswanger disease
- Charcot-Bouchard microaneurysms
49
What signs are seen in vascular multi infarct demetia?
- Dementia
- Gait
- Pseudobulbar signs
50
What signs are seen in binswanger disease?
- Large area of subcortical white matter with myelin and axon loss
51
What signs are seen in charcot-bouchard microaneurysms?
- Associated with chronic hypertension
| - Minute aneurysms in the basal ganglia
52
What is cerebral amyloid angiopathy?
- Lobar hemorrhage
| - Same B-amyloid deposited in the walls of vessels (like in Alz disease) producing microbleeds
53
What is CADASIL?
- Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy
54
What is seen in CADASIL?
- Recurrent strokes and dementia
- Thickening of the media and adventitia
- Loss of smooth muscle cells and basophilic PAS+ deposits
55
When is CADASIL detected?
- Around 35 years old and infarcts typically occur 10-15 years later
56
What gene is seen in CADASIL?
- Auto Dom --> NOTCH 3 gene
57
What are some stroke risk factors?
- HTN
- Diabetes
- Hypercholesterolemia
- Cigarette smoking
- Pos family history
- Cardiac disease
- Prior history of stroke
- Hypercoagulability
58
What should you think if there is a stroke in a young patient?
- Arterial dissection (like in marfan)
- PFO or hypercoagulability
- Sickle cell
59
What is the most frequent cause of a significant subarachnoid hemorrhage?
- Rupture of saccular (berry) aneurysm --> begins as basilar SAH
60
What aneurysms are seen in the anterior circulation?
- Saccular
- Mycotic
- Traumatic
- Dissection
61
Where in the circle of willis are saccular aneurysms found?
- Majority in ACA
| - Secondary location in MCA
62
How can saccular (berry) aneurysms be treated?
- Clipping due to having a neck
63
When do aneurysms usually rupture?
- Fifth decade and slightly more in females
64
What increases the likelihood of ruptured aneurysms?
- Increased intracranial pressure --> straining at stool or sexual orgasm
65
What are some hereditary diseases that have increased incidence of aneurysms?
- If first degree relative is affected
- Infantile polycystic kidney disease
- Ehlers-Danlos type IV
- NF1
- Marfan
66
How do people present with a ruptured aneurysms?
- Worse headache they have ever had
| - Repeat bleeding is common
67
What are people most at risk for a couple of days after SAH?
- Additional ischemic injury from vasospasm affecting vessels bathed in extravasated blood
68
What are the four groups of vascular formations?
- Arteriovenous malformations (AVM)
- Cavernous malformations/hemangiomas
- Capillary telangiectasias
- Venous angiomas
69
What do cavernous malformations look like?
- Distended, loosely organized vascular channels arranged back to back
* ** THERE IS NO BRAIN PARENCHYMA***
70
What regions of the brain are affected by cavernous malformations?
- Cerebellum
- Pons
- Subcortical regions
71
What is seen in cavernous malformations?
- Foci of old hemorrhage
- Infarction
- Calcification seen in surrounding area
72
Who is most likely affect by AVMs?
- Males more than females in their 10-30s
73
What are some symptoms of AVMs?
- Seizure
| - Intracerebral hemorrhage or SAH
74
What do AVMs look like?
- Tangle, worm like vascular channels with prominent pulsatile arteriovenous shunting with high blood flow
75
Where are AVMs most commonly seen?
- MCA and posterior branches (subarachnoid space)
76
What mutation is associated with AVMs?
- KRAS oncogene
77
What are some causes of multifocal vascular disease?
- Cerebral atherosclerosis
- Vessel thrombosis/emboli from carotid or heart
- Cerebral arteriosclerosis from chronic hypertension
78
What is seen in vascular dementia?
- Multiple, bilateral gray matter and white matter infarcts
79
What are the four principal routes of infection?
1. Hematogenous
2. Direct implantation
3. Local extension
4. PNS
80
How does tuberculous meningitis develop?
- Seeding CSF from subepidural or submeningeal granulomas
81
How does herpes simplex and zoster infections spread?
- Produce latent infection of sensory ganglia
- Replicate in schwann cells
- Ascend to the CNS within sensory nerves
82
How does rabies infections spread?
- Bind at or near Ach receptors at the NMJ
| - Ascend to the CNS via motor nerves
83
What is the CNS response to infection?
- Widespread infection --> involving all tissue elements, characteristic of bacterial meningitis and many viral encephalitides
- Functional specialization of different cell populations and of specific neuro-anatomical regions determine the characteristic neurological syndromes
84
What accelerates the development of cerebral edema?
- Accelerated by products released by both living bacteria and antibiotic lysed bacteria
85
What slows the development of cerebral edema?
- Slowed and reversed by corticosteroids
86
What are the symptoms of acute meningitis?
- Headache
- Meningeal irritation signs (Kernig/Brudzinski)
- High fever
- Confusion
- Coma
87
When do symptoms of acute meningitis develop?
- Within several days; however may develop over a few hours with a fulminant course
88
Where is the exudate in pneumococcal meningitis?
- Convexities near sagittal sinus
89
Where is the exudate in H. influenzae meningitis?
- Basal location
90
What is ventriculitis?
- Fulminant infection
| - Inflammation may extend into ventricles
91
What is focal cerebritis?
- Inflammatory cells infiltrate walls of the veins and extend into the brain substance
92
What are some systemic signs that are caused by acute meningitis?
- Ventriculitis
- Focal cerebritis
- Phlebitis --> may lead to venous thrombosis and hemorrhagic infarction
- Leptomeningeal fibrosis --> hydrocephalus
93
What are the complications seen in bacterial meningitis?
- Seizures
- Encephalitis
- Hearing loss, blindness, paralysis
- Fulminant --> esp. with meningococcemia (will see adrenal hemorrhage causing death)
94
What is the gram neg diplococci causing meningitis?
- N. meningitidis
95
What is the gram pos diplococci causing meningitis?
- S. pneumoniae
96
What is the gram neg pleomorphic causing meningitis?
- H. influenzae
97
What is the gram pos cocci causing meningitis?
- S. aureus or s. epi
| - Streptococci
98
What is the gram neg bacilli causing meningitis?
- E. coli or other gram neg
99
Where in the spine is the best place to do a lumbar puncture?
- Between 3rd and 4th lumbar vertebrae
100
How does the CSF differ between bacterial cause and viral cause?
- Bacterial: Cloudy, high neutrophil, low glucose, very high protein levels
- Virus: clear, no neutrophils, high lymphocytes, normal glucose, increased protein levels
101
What are some risk factors for meningitis?
- Age <5 and >60
- DM
- Immunosuppression
- Contiguous infections
- IVDA
- Bacterial endocarditis
- Sickle cell
102
What organisms are most likely to cause meningitis in neonates?
- E. coli
| - Grp B strep
103
What organisms are most likely to cause meningitis in unvaccinated children under 2yo?
- H. influenzae type B
104
What organisms are most likely to cause meningitis in adolescents and young adults?
- N. meningitidis
105
What organisms are most likely to cause meningitis in elderly?
- S. pneumoniae
| - Listeria monocytogenes
106
What organisms are most likely to cause meningitis in immunocompromised individuals?
- S. pneumoniae
- N. meningitidis
- L. monocytogenes
- P. aeruginosa
107
What organisms are most likely to cause meningitis in a basilar skull fracture?
- S. pneumoniae
- H. influenzae
- Grp A beta-hemolytic strep
108
How do patients present with an abscess?
- Progressive focal neurological deficits
| - Signs of increased intracranial pressure may also develop
109
What does the CSF look like in an abscess?
- High WBC
- High protein
- Normal glucose
110
What are some complications seen in ascesses?
- Herniation
- Abscess rupture with ventriculitis or meningitis
- Venous sinus thrombosis (patient dies)
111
What is the treatment for most brain abscesses?
- Surgical drainage and antibiotics
112
What does a brain abscess look like on CT?
- Edema surrounding liquefactive necrosis
113
What is subdural empyema?
- Bacteria or fungus infection of skull bones or sinuses spread to subdural space
114
What is the treatment of subdural empyema?
- Surgical drainage
115
What is associated with an extradural abscess?
- Osteomyelitis
116
Where does N. meningitidis colonize?
- Oropharynx and rhinopharynx
117
What agar is used to grow N. meningitidis?
- Chocolate agar
118
What are the clinical manifestations of N. meningitidis?
- Rapidly progressive septicemia with fever, hypotension, DIC, petechial and purpuric lesions
- Purpura fulminans
- Hemorrhagic infarction of adrenal glands
119
What is purpura fulminans?
- Hemorrhagic skin lesions which progress to gangrene
| - Occurs in distal portion of limbs
120
What are the symptoms of chronic meningitis?
- Fever
- Headache
- Lethargy
- Confusion
- N/V
- Stiff neck
121
What does the CSF look like in chronic meningitis?
- Elevated protein
- Predominantly lymphocytic pleocytosis
- Sometimes low glucose
122
What are some causes of chronic meningitis?
- TB
- Neuroborreliosis
- Neurosyphilis
123
What is seen in mycobacterium tuberculosis diffuse meningoencephalitis?
- Gelatinous or fibrinous exudate in subarachnoid space
| - Obliterative endarteritis --> inflammation infiltrates vessel walls with intimal thickening
124
Where is the predilection in mycobacterium tuberculosis diffuse meningoencephalitis?
- Base of brain --> CNs could be affected
| - Obliterated Cisterns and encases CNs
125
What is needed to diagnose mycobacterium tuberculosis diffuse meningoencephalitis?
- Culture AND smear to increase chance of positive
126
What symptoms are seen in borrelia meningitis?
- Cranial nerve palsy and peripheral neuropathies
| - CSF with antibodies
127
How is borrelia meningitis diagnosed?
- CSF PCR
128
What is meningovascular neurosyphillis?
- Chronic meningitis involving base of the brain
| - Causes communicating hydrocephalus
129
What is seen in meningovascular neurosyphilis?
- Obliterative endarteritis = Heubner arteritis
130
What is paretic neurosyphilis?
- Insidious, but progressive mental deficits associated with mood alterations (delusions of grandeur) that terminate in severe dementia
- Perivascular iron deposits
- Glandular ependymitis --> proliferation of subependymal glia under damaged ependymal lining
131
What is tabes dorsalis?
- Damage to sensory nerves in the dorsal roots
132
What symptoms are seen in tabes dorsalis?
- Impaired joint position sense and resultant ataxia
- Loss of pain sensation
- Joint damage
- Lightening pains
- Absence of deep reflexes
133
What is the main cause of aseptic meningoencephalitis?
- Enteroviruses
134
What does the CSF look like in aseptic meningoencephalitis?
- Lymphocytic pleocytosis
- Moderate increase protein
- Glucose near normal
135
How do most viruses infect the CNS?
- Through nerves
136
What is the inflammatory response to viruses in the brain?
- Lymphocytes
137
What are some symptoms of arthropod borne viral encephalitis?
- Generalized neuro deficits
| - Focal signs
138
What does west nile look like?
- Involves spinal cord and gives a polio like syndrome with paralysis
139
What does the CSF look like in arthropod borne viral encephalitis?
- Colorless
- Slight increase in pressure
- Increased protein
- Normal glucose
140
What is seen in the brain during arthropod borne viral encephalitis?
- Multiple foci of necrosis in both gray and white matter
- Neuronophagia
- Microglial nodules
141
What are the symptoms of HSV-1 encephalitis?
- Alterations in mood, memory, and behavior
142
What does HSV-1 encephalitis do to the brain?
- Necrotizing and hemorrhagic
143
What parts of the brain are most affected by HSV-1 encephalitis?
- Inferior and medial temporal lobes (cingulate gyrus destroyed)
- Orbital gyri of frontal lobes
144
What inclusions are seen in HSV-1 encephalitis?
- Cowdrey type A
145
How do neonates get HSV-2 encephalitis?
- Born by vaginal delivery to women with active primary HSV infection
146
What happens with the herpes zoster infection?
- Latent phase in sensory neurons of dorsal root or trigeminal ganglia
147
What happens when herpes zoster is reactivated?
- Shingles --> painful vesicular skin eruption limited to a single or limited dermatome
- Postherpetic neuralgia syndrome
148
What is postherpetic neuralgia syndrome seen in reactivated herpes zoster infection?
- Persistent pain as well as painful sensation following nonpainful stimuli
149
Who is most likely affected by CMV?
- Fetuses and immunocompromised ind.
150
What happens to the brain in a CMV infection?
- Periventricular necrosis causing severe brain destruction (mainly parenchyma)
- Microcephaly
- Periventricular calcification
151
Where does CMV localize in the brain?
- Paraventricular subependymal regions --> severe hemorrhagic necrotizing ventriculo encephalitis and choroid plexitis
152
Where does poliomyelitis attack?
- Mononuclear cell perivascular cuffs
| - Neuronophagia of the anterior horn motor neurons of the spinal cord
153
What symptoms are seen in poliomyelitis?
- Flaccid paralysis
| - Associated with muscle wasting and hyporeflexia
154
What is the incubation period of rabies?
- 1-3 months
155
How does rabies infect?
- Ascends along peripheral nerves from the wound site
156
What are some symptoms of a rabies infection?
- Paresthesias around wound
- Extraordinary CNS excitability --> violent motor responses progressing to convulsions
- Flaccid paralysis
- Hydrophobia
157
What happens in acute HIV aseptic meningitis?
- Mild lymphocytic meningitis
- Perivascular inflammation
- Some myelin loss
158
What happens in chronic HIV aseptic meningitis?
- Microglial nodules with multinucleated giant cells
159
What happens to the vessels in HIV aseptic meningitis?
- Abnormal prominent endothelial cells and perivascular foamy or pigment-laden macrophages
160
What happens to the white matter in HIV aseptic meningitis?
- Multifocal or diffuse areas of myelin pallor, axonal swelling, and gliosis
161
What is IRIS?
- Immune reconstitution inflammatory syndrome
162
What is seen in IRIS?
- Paradoxical deterioration after starting antiviral therapy
- Exuberant inflammatory response
- Paradoxical exacerbation of symptoms from opportunistic infections
163
What is seen in HIV-associated neurocognitive disorders?
- Mild to florid cognitive changes
| - Persisting despite effective HIV treatment
164
What virus causes progressive multifocal leukoencephalopathy (PML)?
- JC Polypomavirus
165
What does the JC polyomavirus affect?
- Oligodendroglial cells
| - Demyelination principle pathologic effect
166
What occurs in PML?
- Irregular, ill-defined destruction of white matter
| - Subcortical area of demyelination with lipid-laden macrophages in the center with decreased number of axons
167
What causes subacute sclerosing panencephalitis (SSPE)?
- Paramyxovirus
| - Seen in children months-years following early age acute infection with measles
168
What symptoms are seen in SSPE?
- Cognitive decline
- Spasticity of limbs
- Seizures
169
What happens in the brain during SSPE?
- Widespread gliosis and myelin degeneration
- Viral inclusions
- Variable inflammation of white and gray matter
- Neurofibrillary tangles
170
What organisms are the biggest causes of fungal meningoencephalitis?
- Candida albicans
- Mucor
- Aspergillus
- Cryptococcus neoformans
171
Which meningitis causing fungus is most likely found in people with diabetes?
- Mucormycosis
172
Who is most likely to develop chronic meningitis by cryptococcus neoformans?
- People with immune dysfunction --> Immunosuppressed
173
Where is cryptococcus gattii likely to cause chronic meningitis?
- Immunocompetent ind.
174
What is used to prep the CSF in cryptococcus meningitis?
- India ink prep
175
How is cryptococcus meningitis diagnosed?
- Look at CSF for the cryptococcal polysaccharide antigen and culture
176
What does toxoplasmosis gondii do to the brain?
- Brain abscess
177
Where is the brain abscess due to toxoplasmosis located?
- Near gray-white junction of cerebral cortex and deep gray nuclei
178
What does a toxoplasmosis brain abscess look like on CT?
- Ring enhancing lesion
179
What does the histology look like for toxoplasmosis?
- Central foci of necrosis
- Petechial hemorrhages surrounded by acute and chronic inflammation
- Macrophage infiltration and vascular proliferation
- Free tachyzoites and encased bradyzoites
180
How does naegleria fowleri (brain eating ameba) get into the brain?
- Through the nose when contaminated water goes through cribiform
- Located in warm freshwater
181
What does the brain look like in rocky mountain spotted fever?
- Starry sky on diffusion weighted imaging
182
What is the cause for prion diseae?
- PrP prion protein
183
What symptoms are seen in prion disease?
- Rapidly progressive neurodegenerative disorders
184
What does prion disease do to the brain?
- Microscopic spongiform change --> intracellular vacuoles in neurons and glia
185
How does someone get CJD?
- Corneal transplant
- Brain implantation of electrodes
- HGH
186
What are the symptoms of CJD?
- Rapidly progressive dementia with startle myoclonus
| - Only about 7 months
187
How is the vCJD in the UK different than CJD?
- Kuru plaque --> extracellular deposits of aggregated abnormal protein
- Congo red + and PAS+
188
What is fatal familial insomnia?
- Sleep disturbances initially
| - Aspartate substitution
189
What symptoms are seen in fatal familial insomnia?
- Ataxia
- Autonomic disturbances
- Stupor
- Finally coma
