Cerebrovascular Disease

Question 1

lacune, or lacunar infarct,

Answer 1

small cavity caused by a stroke.

Question 2

transient ischemic attack (TIA)

Answer 2

brief episode of neurologic dysfunction caused by focal brain or retinal ischemia, with clinical symptoms typically lasting less than one hour but as long as 24 hours and without evidence of tissue death..

Question 3

Silent stroke

Answer 3

Silent stroke refers to the presence of vascular-related brain injury seen on neuroimaging without associated clinical symptoms.

Question 4

Stoke % of cognitive impairment?

% of dementia?

Answer 4

64% of individuals with a history of stroke

one-third develop frank dementia

Question 5

stroke risk after TIA

Answer 5

Approximately 15% of all strokes are heralded by a TIA, the majority of which occurred within 30 days of the first stroke

Question 6

Prevalence of Ischemia vs. intracerebral hemorrhagic vs. subarachnoid hemmorhagic

Answer 6

87 vs. 10 vs. 3

Question 7

Cerebral Vasculature

- Origin and make up of Circle of Willis

Answer 7

Brain blood supply: Internal carotid arteries and the vertebral arteries
The internal carotid arteries give rise to the anterior circulation, and the vertebral arteries to the posterior circulation.
The vertebral arteries join to form the basilar artery, which converges with the two internal carotid arteries, thus forming the circle of Willis, a complete arterial ring at the base of the brain connecting the anterior and posterior circulation systems.

Aphasia, visual field cuts, hemi-neglect, and sensory-motor deficits typically suggest hemispheric regions; while vertigo, nausea and vomiting, and ataxia usually imply vertebrobasilar territory.

Question 8

Irrigation of Circle of Willis by artery

Answer 8

The circle of Willis gives rise to all major cerebral blood vessels, including the three main arteries that supply the cerebral hemispheres: the anterior cerebral arteries (ACAs), the middle cerebral arteries (MCAs), and the posterior cerebral arteries (PCAs). The ACAs and MCAs are connected by the anterior communicating artery (ACom) and comprise the anterior circulation system, supplying most of the anterior medial cortex, from the frontal lobes to the anterior parietal lobes, as well as the majority of cortex along the dorsolateral convexity.
The PCAs constitute the posterior circulation system and supply the inferior and medial temporal lobes and the medial occipital cortex.

Anterior and posterior circulations are joined by the posterior communicating arteries (PCom).

Question 9

Suggestive features of anterior and posterior stroke

Answer 9

Aphasia, visual field cuts, hemi-neglect, and sensory-motor deficits typically suggest hemispheric regions; while vertigo, nausea and vomiting, and ataxia usually imply vertebrobasilar territory.

Question 10

Time to cell death

Answer 10

The brain can function for only six to eight minutes if oxygen and glucose fall below critical levels, and complete blockage of blood flow will typically result in loss of consciousness within seconds.

Question 11

diaschisis

Answer 11

areas of reduced flow and metabolism at sites remote from the infarction site. This results from “stealing” of blood flow to distal brain regions. It is therefore possible to see clinical deficits corresponding to deafferentation of remote and/ or ipsilateral cortical structures following a subcortical infarct.

Question 12

Factors that impact tissue damage

Answer 12

location and duration of ischemia,
individual variations in vascular structure and collateral blood supply,
edema of the surrounding tissue,
and type and timing of therapeutic intervention.

Secondary insults such as hypotension and hypoxia are devastating in this setting and usually result in a completed territorial infarction.

Question 13

Thrombosis

Answer 13

Obstruction of blood flow due to a blood clot, which narrows or occludes the lumen of a vessel most commonly due to underlying atherosclerosis.

Question 14

Embolism

Answer 14

material from a distant site lodges in a cerebral vessel and occludes blood flow. Emboli are often fragments of a thrombus but could also be composed of fat, plaque, air, bacteria, tumor cells, or particles from an injection. Most commonly arise from the heart.

Question 15

Ischemic stroke Clinical Presentation for left and right hemisphere

Answer 15

In general, left hemisphere strokes are associated with aphasia and apraxia, while right hemisphere strokes are associated with neglect, constructional dyspraxia, and dysprosody..

Question 16

Left MCA superior division

Answer 16

Nonfluent, or Broca’s aphasia, and right face and arm weakness of the upper motor neuron type. In some cases there may also be some right face and arm cortical-type sensory loss

Question 17

Left MCA inferior division

Answer 17

Fluent, or Wernicke’s, aphasia and a right visual field deficit. There may be some right face and arm cortical-type sensory loss. Motor findings are usually absent. Patients may initially seem confused or crazy, but otherwise intact, unless carefully examined. Some mild right-sided weakness may be present, especially at the onset of symptoms.

Question 18

Left MCA deep territory

Answer 18

Right pure motor hemiparesis of the upper motor neuron type. Larger infarcts may produce cortical deficits as well, such as aphasia..

Question 19

Left MCA stem

Answer 19

Combination of the above, with right hemiplegia, right hemianesthesia, right homonymous hemianopia, and global aphasia. There is often a left gaze preference, especially at the onset, caused by damage to left hemisphere cortical areas important for driving the eyes to the right.

Question 20

Left ACA

Answer 20

Right leg weakness of the upper motor neuron type and right leg cortical type sensory loss. Grasp reflex, frontal lobe behavioral abnormalities, and transcortical aphasia can also be seen. Larger infarcts may cause right hemiplegia.

Question 21

Left PCA

Answer 21

Right homonymous hemianopia. Extension to the splenium of the corpus collosum can cause alexia without agraphia. Larger infarcts including thalamus and internal capsule may cause aphasia, right hemisensory and right hemiparesis.

Question 22

TIA treatment

Answer 22

10% and 50% of patients have a stroke within three months of TIA, with half of those occurring within 48 hours, there is great impetus for early evaluation and treatment. Early carotid endarterectomy following TIA has become an increasingly common means to decrease recurrence and risk of stroke with favorable cost-benefit outcomes

Fewer than one in six patients with symptom duration of at least one hour will demonstrate full resolution of symptoms by 24 hours

With MMSE 1-7 days post TIB, 40% of the acute group had transient cognitive impairment at once month and higher five-year risk of subsequent cognitive impairment.

Question 23

Hemorrhagic Stroke

Answer 23

• 2nd most common subtype
• spontaneous bleeding within the brain or subarachnoid space from vessel leakage or rupture
• Primary brain damage from ICH occurs from interruption of blood supply, direct mechanical injury from the expanding clot, increased intracranial pressure (ICP), and/ or herniation through the tentorium secondary to mass effect. In addition, the secondary effect of an ICH is a powerful inflammatory reaction triggered by toxic elements in the blood clot. Hemorrhagic stroke damage is manifested within the primary vascular territory affected by the disrupted perfusion, and also in overlapping or shared areas, referred to as watershed zones.

Question 24

Hemorrhagic Stroke Causes

Answer 24

majority of hemorrhagic strokes are attributable to hyper-tension, vascular malformations, and aneurysms.

• most common etiology of spontaneous ICH is the chronic effect of hypertension. Bleeding related to hypertension usually involves small penetrating vessels that branch directly off major intracerebral arteries at up to 90-degree angles. It is thought that penetrating arteries are more vulnerable to effects of hypertension because they are directly exposed to the larger vessel’s pressure, which is ordinarily reduced by a gradual decrease in the size of other branching vessels. The territory of these vessels is the basal ganglia, thalamus, pons, and subcortical white matter. Many hyper-tensive hemorrhages begin as slow leaks, and in contrast to subarachnoid hemorrhage or embolic stroke, neurologic symptoms often do not begin abruptly and are not maximal at the onset. Rather, the major bleed may be preceded for weeks to months by fluctuating neurologic signs or seizure, and at onset, symptoms typically increase gradually over minutes or hours. Classic symptoms include severe headache, vomiting, decreased level of consciousness, oculomotor disturbance, and nuchal rigidity (neck stiffness). However, clinical signs will vary based on the size and location of the bleed

Question 25

Clinical presentation of intracranial hemorrhage by location

Answer 25

Most often affects the parietal and occipital lobes. Parietal: contralateral sensory impairment. Associated with a higher incidence of seizures. Occipital: dense contralateral homonymous hemianopsia.
Frontal: contralateral plegia or paresis of the leg with relative sparing of the arm.

Putamenal Commonly occurs along white matter fiber tracts. Hemiplegia, hemisensory loss, homonymous hemianopsia, gaze palsy, stupor, and coma.

Cerebellar Originates in the dentate nucleus, extends into the hemisphere and fourth ventricle, and possibly into the pontine tegmentum. Imbalance, vomiting, headache, neck stiffness, gaze palsy, and facial weakness. May become stuporous due to brain stem compression if the hemorrhage is unrecognized or untreated.

Thalamic May extend in a transverse direction to the posterior limb of the internal capsule, downward to put pressure on the tectum of the midbrain, or may rupture into the third ventricle. Hemiparesis, hemisensory loss, occasionally transient homonymous hemianopsia or quadrantanopsia. May be an upgaze palsy with miotic pupils that are unreactive, peering at the tip of the nose, skewed, or “wrong way eyes” toward the weak side. Aphasia if dominant hemisphere; neglect or anosognosia in nondominant hemisphere.

Aphasia if dominant hemisphere; neglect or anosognosia in nondominant hemisphere. Pontine Medial hematoma that extends into the base of the pons, disruption of the reticular activating system. Deep coma within first few minutes, total paralysis, pinpoint pupils, absent horizontal eye movements, facial palsy, deafness, and/ or dysarthria if awake.

Question 26

Arteriovenous Malformation

Answer 26

Focal symptoms can occur if the AVM forms a pathway in which blood flows away from the site and causes hypoperfusion of brain tissue. AVMs are susceptible to spontaneous rupture because of their thin vessel walls.

.

Question 27

Arteriovenous Malformation - clinical presentation

Answer 27

Patients with AVMs may be asymptomatic until later in life, though symptom onset is often between the ages of 10 and 40. ICH is the most common clinical presentation (between 40% to 80% of AVM cases). Prior to rupture, headaches and seizures are common.

Question 28

Arteriovenous Malformation - treatment effectiveness

Answer 28

The long-term benefit of treatment for unruptured AVMs is unclear. A systematic review and meta-analysis of observational studies concluded that all available treatments were associated with considerable risks, including a 5%– 7% median rate of permanent neurologic complications or death, and incomplete efficacy of 13%– 96%

Question 29

AVM neuropsych implications

Answer 29

AVMs less consistently result in well-lateralized or focal neuropsychological impairments compared to ischemic stroke. The variability in neuropsychological outcome may be due to AVM pathology resulting in differences in the development of cerebral (re-) organization, as well as variation in site and rate of expansion. When asymmetrical neuropsychological findings are present, the AVM laterality can be predicted as accurately as in embolic stroke. Interestingly, developmental learning disorders have been found in adults with AVMs at a rate four times that of the general population (Lazar et al., 1999). Neuropsycho-logical functioning has been shown to improve postsurgery and may be attributable to the reduced mass effect of the AVM or surrounding edema. Alternatively, improvement may be related to eliminating the “steal effect” in which shunting through the AVM results in decreased cerebral perfusion in the surrounding area

Question 30

Cavernous Malformation

Answer 30

large vascular lumen with collagenous walls lined with a layer of endothelial cells and may vary in size from 2 mm to several centimeters.

Question 31

Aneurysm - types

Answer 31

Saccular Berry-shaped with a narrow stem. Most commonly located in the anterior circulation. Dissecting Caused by a tear along the innermost layer of the vessel wall, with blood subsequently leaking in between layers of the wall. Often result of traumatic brain injury. Fusiform Bulges out on all sides (circumferentially), forming a dilated artery. Often associated with atherosclerosis.

Question 32

Cerebral Amyloid Angiopathy

Answer 32

deposition of the protein beta amyloid in small and midsized blood vessels of the brain and leptomenginges, weakening the vessel walls and making them vulnerable to rupture.
.

Question 33

Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy - CADASIL

Answer 33

Pathology of CADASIL involves amyloid-negative angiopathy involving small arteries and capillaries primarily in the brain, which result in loss of the periventricular subcortical white matter, lacunar infarcts in the basal ganglia, thalamus, and brain stem, and chronic ischemia

CADASIL typically manifests with ischemic episodes, migraine with aura, cognitive impairment, or psychiatric disturbance. Ischemic episodes are nearly always subcortical with a classic lacunar syndrome presentation (pure motor stroke, ataxic-hemiparesis, dysarthria– clumsy hand syndrome, sensorimotor deficit). Strokes are often recurrent, leading to gait disturbance, urinary incontinence, and pseudobulbar palsy. Migraine with aura occurs in about 30% of CADASIL cases and is usually an early symptom

Question 34

CADASIL neuropsychology

Answer 34

Cognitive impairment is a common clinical manifestation of CADASIL and approximately 75% of carriers eventually develop dementia

executive impairment was present in all individuals, and attention and memory were also affected (Buffon et al., 2006). Verbal fluency, ideational praxis, and error monitoring have also been described (Peters et al., 2005). Recognition memory, verbal episodic memory, and visuo-spatial skills may be relatively spared and severe aphasia and agnosia are rare, though the cognitive pattern becomes more homogeneous and diffuse late in the course of CADASIL. Major depression and apathy related to executive dysfunction occur in about 20%– 30% of patients with CADASIL. Other manifestations include severe mood swings, panic disorder, visual hallucinations, and transient delusions. These episodes can precede other signs of CADASIL pathology or MRI findings. Overall, CADASIL cases may initially present with psychiatric dysfunction that is followed by pervasive cognitive impairment later in disease course

Question 35

Moyamoya Disease

Answer 35

It is a chronic progressive cerebrovascular disease characterized by bilateral stenosis or occlusion of the arteries around the circle of Willis with prominent arterial collateral circulation.

seen in a number of other medical conditions; therefore, the term moyamoya phenomenon or moyamoya syndrome is used to differentiate from idiopathic moyamoya disease.

Question 36

Moyamoya Disease - neuropsychology

Answer 36

progressive, with stepwise cognitive changes due to repeated ischemic stroke or hemorrhage. In studies with long-term follow-up of untreated patients, progressive neurologic deficits and poor outcome were reported in 50%– 66%.

Executive functioning was the most common area of difficulty.

Question 37

Vascular Cognitive Impairment and Vascular Dementia

Overlap with AD

Answer 37

20% of cases of dementia, second only to Alzheimer’s disease

a diagnosis of VaD does not exclude the presence of Alzheimer pathology. In fact, the presence of vascular pathology increases the risk of Alzheimer’s disease

up to one-third of all-cause late-life dementia cases show significant vascular pathology at postmortem

Question 38

VaD Diagnosis types - criteria

Answer 38

4 bodies have 4 criteria including DSM:

criteria identify different patients and are not interchangeable, contributing to variations in epidemiologic estimates.

four diagnostic approaches vary based on how dementia is defined:
what types of cerebrovascular disease are included:
what disorders must be specifically excluded:
whether focal findings are required, whether the presence of vascular disease must be corroborated by neuroimaging,
whether a temporal relationship between stroke event and cognitive decline is required.

none of the available criteria distinguished mixed dementia from vascular dementia or recognized early vascular cognitive changes

More recently, a fifth approach was proposed by a joint American Heart Association and American Stroke Association statement that provided diagnostic criteria for probable and possible VaD, and probable, possible, and unstable vascular cognitive impairment (VCI) (Gorelick et al., 2011).

-> VCI is presently conceptualized as “a syndrome with evidence of clinical stroke or subclinical vascular brain injury and cognitive impairment affecting at least one cognitive domain”

particular attention to tasks involving information processing speed, set-shifting, and working memory, based on the generally accepted notion that executive dysfunction is a key aspect of VCI.

Question 39

VaD pathologies

Answer 39

At least three common pathologies contribute substantively to VaD.

• large artery infarctions,
• small artery subcortical infarctions or lacunes,
• and chronic subcortical ischemia
• Lacunar infarctions and chronic ischemic changes in the white matter share a common primary vascular pathology of small penetrating arteries— and therefore tend to occur together and are particularly common in individuals with hypertension or diabetes and in the elderly.
• clinical manifestations attributed to small-artery disease and associated with Vascular Cog Impairment are retinopathy and the presence of cerebral microbleeds in the deep hemispheric and infratentorial regions.
• evidence of diffuse blood-brain barrier dysfunction throughout the white matter with lacunar infarction.

Chronic subcortical microischemia can result in cognitive impairment even in the absence of ischemic lesions (Balestrini et al., 2013) and is a more frequent clinical-pathologic correlate of VCI and VaD than multiple large infarcts (Hulette et al., 1997; Jellinger, 2013).

Deep white matter tracts are particularly susceptible to vascular pathology, in part because white matter is marginally perfused and particularly vulnerable to alterations in CBF and disruption of the blood-brain barrier, both of which contribute to oxidative stress, inflammation, and subsequent demyelination.

role of vascular insults as initiator, stimulator, or additive contributor to VaD is significantly related to lesion volume, number, and location. Areas of strategic importance for deficits may be cortical (i.e., hippocampus, angular gyrus, frontal lobe) or subcortical (i.e., thalamus, caudate, genu of the internal capsule). Thalamic damage may be a particularly important contributor to cognitive impairment

Even a single stroke in so-called strategic areas can result in prominent cognitive impairment. This is sometimes referred to as “strategic infarct dementia,” though these cases generally have a static presentation rather than a degenerative course. Similarly, other vascular events may cause significant cognitive impairment (e.g., subarachnoid hemorrhage, impairment after cardiac bypass surgery, water-shed infarction) but are not generally considered with VaD because of the lack of expected progression.

Question 40

VaD Neuropsychological Implications and differences vs. AD

Answer 40

vascular dementia classically is associated with an acute onset and fluctuating intensity of symptoms and a stepwise decline in cognitive functioning combined with evidence of cerebrovascular disease (e.g., focal neurological signs).

stepwise trajectory is typically expected with frank strokes rather than chronic microischemic insults that may have a more slowly progressive course. Alzheimer’s disease is typically associated with greater memory dysfunction and fewer executive deficits than VaD in early stages; however, the reverse is not always true (Reed et al., 2007). Despite extensive study, there remains no clear consensus of which cognitive functions or neuropsychological tests best discriminate between VaD and Alzheimer’s disease

White matter pathology and subsequent disruption of fronto-subcortical networks, particularly associated with chronic subcortical microischemia, are thought to lead to slowed information processing speed, the neurocognitive symptom most commonly associated with VCI/ VaD. In general, other symptoms associated with VaD include attention deficits, executive dys-function, reduced phonemic verbal fluency, and impaired motor programming.

memory findings, relatively less prominent impairment is expected than in Alzheimer’s disease, and recognition memory performance tends to be better than free recall. However, the neuropsychological profile will depend on location and degree of the underlying cerebrovascular pathology. Gait disturbance, parkinsonism, urinary incontinence, and depression are more frequently implicated in VaD, relative to other dementias.

Question 41

Mixed Dementia - incidence

Answer 41

Alzheimer’s disease with cerebrovascular disease, is recognized as a separate entity due to the common co-occurrence of Alzheimer’s disease and VaD pathology. Approximately 30% of patients with a clinical diagnosis of VaD demonstrate Alzheimer’s disease pathology at autopsy / /

50% of those with Alzheimer’s disease diagnoses will show vascular pathology at autopsy

Elderly patients with dementia may in fact be more likely to have mixed pathology

Alzheimer’s disease and VaD may have common etiologies and influence each other’s course.