NUPY 5_Cerebrovascular disease

Question 1

**Stroke or TIA?
* acute onset neurologic signs and symptoms with a vascular basis
* persist beyond 24 hours
* imaging studies demonstrate infarction

Answer 1

Stroke

Question 2

**Stroke or TIA?
* acute onset
* neurologic signs and symtoms with a vascular basis
* symptoms resolve within 4 hours
* evidence of brain infarction seen on imaging

Answer 2

Stroke

Presence of infarction implies a stroke diagnosis

Question 3

**Stroke or TIA?
* acute onset
* neurologic signs and symtoms with a vascular basis
* symptoms resolve within 4 hours
* no evidence of brain infarction seen on imaging

Answer 3

TIA

Question 4

ischemic but reversibly dysfunctional tissue surrounding a core area of infarction

Answer 4

Penumbra

target of revascularization therapy

Question 5

2 causes for increase in intracellular calcium during cerebral ischemia

Answer 5

1. Decreased ATP–>membrane ion pumps stop functioning–>neurons depolarize–>intracellular calcium rises
2. Neuronal depolarization –>glutamate release from synaptic terminals–>activates NMDA receptors–>calcium influx

Question 6

4
mechanisms of ischemic-reperfusion injury

Answer 6

Oxidative stress
Intracellular calcium overload
Inflammation
Activation of the complement system

Question 7

Causes of global cerebral ischemia

aka diffuse hypoxic ischemic encephalopathy

Answer 7

1. Generalized reduction in cerebral perfusion: Cardiac arrest, MI, shock
2. Decreased oxygen carrying capacity of blood: CO or cyanide poisoning

Question 8

List the CNS cell types that are most sensitive to hypoxia

Answer 8

1. Pyramidal neurons in the hippocampus
2. Cerebellar Purkinje cells
3. Pyramidal neurons in the cerebral cortex (esp. III and V)

Question 9

**What’s the level of the lesion? **
Posture - Flexion of the elbows and wrists and supination of the arm , lower limbs extended

Answer 9

above the red nucleus/ bilateral damage rostral to the midbrain

decorticate posturing

Question 10

**What’s the level of the lesion? **
Posture - Extenmsion of the elbows and wrists with pronation , lower limbs extended

Answer 10

Below the red nucleus/ damage to motor tracts caudal to the midbrain

decerebrate rigidity

Question 11

**Vegetative state/ brain-death? **
* awake but non-responsive
* Persistent yawning, cough, swallow, limb and head movement functions
* Few to no responses to external/ internal environment
* Absent response to visual stimuli
* Decerebrate/ decorticate posturing

Answer 11

Vegetative state

Question 12

What confounding factors should be ruled out before diagnosing brain death?

Answer 12

1. Hypothermia
2. Drug intoxication

Question 13

2 elements required for diagnosis of brain death after ruling out confounding factors

Answer 13

1. Widespread cortical destruction
2. Brainstem damage

Question 14

List signs of brainstem damage

Answer 14

• Pupils dilated and non reactive bilaterally
• Corneal reflex absent
• Loss of oculocephalic and oculovestibular reflexes
• complete and irreversible apnea

Question 15

Signs of widespread cortical destruction

Answer 15

Deep coma, unresponsive to all forms of stimulation

Question 16

Clinical consequences of a watershed infarct in the MCA-ACA borderzone

Answer 16

proximal arm and shoulder weakness with preserved strength distally in the lower limbs (person in a barrel syndrome)

Question 17

Gross morphology of a borderzone infarct

Answer 17

bilateral,wedge-shaped, strips that are parallel and a few centimeters lateral to the interhemispheric fissure

Question 18

Microscopic morphology of a borderzone (watershed) infarct

Answer 18

diffuse laminar necrosis

Question 19

Pattern of necrosis in a cerebral infarct

Answer 19

Liquefactive
(release of hydrolytic enzymes)

Question 20

Causes of cerebral vessel occlusion by emboli

Answer 20

• Cardiac mural thrombi – atrial fibrillation, myocardial infarction, valvular heart disease
• Originating from arteries- atheromatous plaques within the carotids
• paradoxical thromboemboli – patent foramen ovale/atrial septal defect.

Question 21

Causes for an ischemic stroke due to cerebral vasospasm

Answer 21

1. Subarachnoid hemorrhage
2. Drugs- cocaine, marijuana, amphetamines, pseudoephedrine

Question 22

Identify the vessel most likely to have been occluded:
right face and arm weakness
right face and arm sensory loss
Expressive aphasia

Answer 22

left MCA

Question 23

Identify the vessel most likely to have been occluded:
Left face and arm weakness
Left face and arm sensory loss
Left hemineglect

Answer 23

Right MCA

Question 24

Identify the vessel most likely to have been occluded
* right pure upper motor hemiparesis

Answer 24

Lenticulostriate branches of the left MCA (damage to basal ganglia and genu of internal capsule on the left side)

Question 25

**Identify the vessel most likely to have been occluded** * left pure upper motor hemiparesis

Answer 25

Lenticulostriate branches of the right MCA (damage to basal ganglia and genu of internal capsule on the right side)

Question 26

**Identify the vessel most likely to have been occluded:** * Right leg weakness - damage to motor cortex * right leg sensory loss -damage to sensory cortex. * Grasp reflex, frontal lobe behavioral abnormalities * transcortical aphasia - seen if the prefrontal cortex and supplemental motor areas are involved.

Answer 26

Left ACA

Question 27

**Identify the vessel most likely to have been occluded:** * Left leg weakness - damage to motor cortex * Left leg sensory loss -damage to sensory cortex. * Grasp reflex, frontal lobe behavioral abnormalities * Left hemineglect - seen if the prefrontal cortex and non-dominant association areas are involved.

Answer 27

Right ACA

Question 28

**Identify the vessel most likely to have been occluded:** * contralateral homonymous hemianopia with macular sparing * Contralateral hemisensory loss

Answer 28

PCA

Question 29

**See the attached image and identify whether it is an ischemic or a hemorrhagic stroke:** 78 year old with focal neurologic deficits 1 day ago

Answer 29

Ischemic stroke (Low attenuation on CT) | At about 24 hours, the lesion becomes relatively well circumscribed

Question 30

Most cerebral infarcts develop as pale infarcts. Why do some undergo secondary hemorrhagic transformation?

Answer 30

Ischemic reperfusion injury

Question 31

Timeline at which this morphologic finding is most likely to be visible:

Answer 31

6-12 hours | red neurons

Question 32

****Timeline at which this morphologic finding is most likely to be visible: Foamy macrophages first become visible

Answer 32

48-72 hours

Question 33

Fomay macrophages that appear after a cerebral infarct to perform phagocytosis originate from which cells?

Answer 33

Activated microglia

Question 34

****Timeline at which this morphologic finding is most likely to be visible: reactive astrocytes and newly formed vessels begin to be seen at the periphery

Answer 34

By 1 week

Question 35

****Timeline at which this morphologic finding is most likely to be visible: dense meshwork of glial fibers admixed with new capillaries and perivascular connective tissue

Answer 35

After several months

Question 36

Most common risk factors for a lacunar stroke

Answer 36

**chronic hypertension,** hyperlipidemia, diabetes

Question 37

Commonly affected regions in a lacunar stroke

Answer 37

putamen, caudate nuclei, internal capsule,thalamus

Question 38

2 morphologic lesions associated with lacunar strokes

Answer 38

1. Lipohyalinosis 2. Microatheromas

Question 39

**Diagnosis? ** 82 year old male with chronic hypertension, presents with acute onset focal neurologic deficits and then passes away. Gross morphology is shown in the attached image.

Answer 39

Lacunar infarct

Question 41

Predominant and earliest mechanism of cerebral edema in an ischemic stroke

Answer 41

Cytotoxic edema- to failure of the Na+/K+-ATPase pump followed by vasogenic edema due to damage to the blood brain barrier.

Question 42

most common cause of a hemorrhagic stroke involving the basal ganglia and thalamus

Answer 42

hypertension

Question 43

most common cause of a hemorrhagic stroke in the lobes of cerebral hemispheres in the elderly

Answer 43

cerebral amyloid angiopathy

Question 44

most common location of hemorrhagic strokes due to hypertension

Answer 44

putamen (50-60%)

Question 45

minute aneurysms in the brain that occur in small penetrating blood vessels and cause hemorrhagic styrokes when they rupture and bleed

Answer 45

Charcot Bouchard microaneurysms

Question 46

How does hypertension cause a hemorrhagic stroke?

Answer 46

accelerated atherosclerosis in larger arteries, hyaline arteriolosclerosis in smaller arteries-->more vulnerable to rupture than normal vessels--> hemorrhagic stroke

Question 47

Is this an ischemic or a hemorrhagic stroke?

Answer 47

Hemorrhagic stroke ( increased density on nonenhanced CT scans of the brain immediately after the event)

Question 48

clinical signs of a putamen bleed

Answer 48

contralateral hemiplegia, slurred speech, eyes deviate away from lesion; upper brainstem compression (coma), decerebrate rigidity, bilateral Babinski signs, fixed, dilated pupils, irregular/ intermittent respiration

Question 49

most common cause of a non traumatic subarachnoid hemorrhage

Answer 49

Saccular (berry) aneurysm

Question 50

Most common sites of a berry aneurysm in descending order of frequency

Answer 50

(1) the proximal portions of the anterior communicating artery (2) at the origin of the posterior communicating artery from the stem of the internal carotid (3) at the first major bifurcation of the MCA, and (4) at the bifurcation of the internal carotid into middle and anterior cerebral arteries

Question 51

CSF finding in subarachnoid hemorrhage

Answer 51

Xanthochromia

Question 52

Radiologic findings in subarachnoid hemorrhage

Answer 52

Blood in the basal cisterns and sylvian fissures

Question 53

Complications of subarachnoid hemorrhage

Answer 53

1. Rebleeding 2. Seizures 3. Communicating hydrocephalus 4. Vasospasm 5. Hyponatremia

Question 54

most common mechanism of hydrocephalus in subarachnoid hemorrhage

Answer 54

blood-induced impairment of absorption of cerebrospinal fluid by the arachnoid granulations.

Question 55

Most likely cause of a hemorrhagic stroke in an individual with the following radiologic finding

Answer 55

arteriovenous malformation | tangled networks of wormlike vascular channels

Question 56

* tufts of capillary sinusoids that form within the deep hemispheric white matter and brainstem * no normal intervening neural structures * Risk of intracranial hemorrhage

Answer 56

cavernous hemangioma

Question 57

accumulation of cognitive deficits from serial strokes in a stepwise manner Etiology: Multifocal vascular disease due to cerebral atherosclerosis

Answer 57

vascular dementia

Question 58

subtype of vascular dementia that mainly involves the subcortical white matter

Answer 58

Binswanger disease