Stroke

Question 1

Cerebrovascular Accident (CVA)

Answer 1

Distruption in cerebral circulation causing a sudden loss of neruons and neurological function

Question 2

Ischemic Strokes (80%)
Name the etiology from most -> least

Answer 2

1. Thrombotic
   - Blood clot fromed w/in the vessel wall in the brain interrupts cerebral blood flow
2. Embolic
   - An embolus is formed elsewhere in the body, dislodges and travels through the circulatory system to lodge in the cerebral arteries’ vessels interrupting cerebral BF
   - SUDDEN ONSET as the lumen of the blood vessel becomes suddenly occulded
3. Low Systemic Perfusion
   - May be due to cardiac failure or significant blood loss leading to systemic hypotension and thus decrease cerebral BF (ex. gunshot wound)

Question 3

Transient Ischemic Accident (TIA)

Answer 3

Ischemia W/O tissue death which causes a transient episode of neurological dysfunction

• Typically resolves in 24 hours or less
• Considered a warnign sign for a CVA

Question 4

Ischemic Penumbra

Answer 4

Area surrounding the ischemic event

• Penumbra area may remain viable following an ischemic event for several hours d/t supply of collateral aterties to the area = window of opportunity to intervene
• One of the main priorities immediately following an ischemic stroke is to attempt to save the ischemic penumbra

Thrombolytic agents are administered WITHIN 4.5 hours following onset of symptoms and attempts are made to DEC ICP from cerebral edema

Thrombolytics are NOT appropratie for HEMORRHAGIC strokes

Question 5

Hemorrhagic Strokes (~20%)

Types

Answer 5

1. Intracerebral
   - D/t a rupture or leak of a weak blood vessel in the brain
   = INE compressive forces = INC ICP & futher edema = INC compression
2. Subarachnoid
   - D/t an anteriovenous malformation or a ruptured aneursym which causes bleeding in the subarachnoid space

Least common etiology
Typically SUDDEN onset
INC mortality rate

Question 6

Arteriovenous Malformation

Definition & Issue

Answer 6

A congential defect resulting in a tangle of abnormal arteries and veins, which bypass the capillary system

• progressive dilation with age
• eventual bleeding in ~50% of AVM cases

Question 7

Major RF specific to women?

Answer 7

1. Early menopause
2. Estrogen supplementation
3. Pregnancy, birth, first 6 weeks post-partum
4. Preclampsia

Preeclampsia is a serious condition that can happen after the 20th week of pregnancy or after giving birth (called postpartum preeclampsia). In addition to causing high blood pressure, it can cause organs, like the kidneys and liver, to not work normally

Question 8

What does the ACA supply?

Answer 8

• Medial aspect of cerebral hemisphere (frontal & parietal lobes)
• Subcortical structures (basal ganglia, anterior fornix, corpus callosum)

Question 9

Anterior Communicating Artery

How does it perfuse the proximal ACA & how may that have an impact?

Answer 9

Occulsion is PROXIMAL to the anterior communicating artery = minimal deficits

Occulsion is DISTAL to the anterior communicating artery = greater deficits
* Both ends feed into the ACA have been blocked = no potential for collatoral perfusion

Question 10

Common characteristics of an ACA stroke…

(7)

Answer 10

1. Contralateral hemiparesis & hemi-sensory loss
2. LE affected > UE
3. Urinary incontinence
4. Abuila = absence in willpower OR inability to act decisively
5. Akinetic Mutism = pt do not move much as well as speak often
6. Apraxia = motor planning
7. BROCA’s Aphasia (frontal lobe) = Production of speech
   * Difficulty with motor aspect - no issues w/ comprehension

Question 11

What does the MCA supply?

Answer 11

• Lateral aspect of the cerebral hemisphere (frontal, parietal, & temporal)
• Subcortical structures (5)
  1. Internal capsule
  2. Corona radiata
  3. Globus pallidus -BG
  4. Caudate -BG
  5. Putament - BG

Question 12

What is the most common site of occulusion in stroke?

Answer 12

MCA
* Occulusion of the proximal MCA results in extensive neurological damage

Question 13

Common characteristics of a MCA stroke…

(7)

Answer 13

1. Contralateral hemiparesis & hemi-sensory loss of face, UE, & LE
2. UE affected > LE
3. Contralateral homonymous hemianopia
4. BROCA’s aphasia (frontal lobe)
5. WERNICKE’s aphasia (temporal lobe)
6. Global aphasia = nonfluent speech + poor comprehension - combination of both
7. Perceptual deficits
   - unilateral neglect
   - anosognosia
   - apraxia
   - spatial disorganization/ depth perception - if lesion is in non-dominant hemisphere (right)

Question 14

What is the more dominant hemisphere?

Answer 14

LEFT hemisphere is often the DOMINANT hemipshere

Question 15

Homonymous Hemianopia

What does this mean?

Answer 15

Homonymous = loss on the same side of both eyes
Hemianopia = loss of visual field on one side of midline

Homonymous hemianopia is a loss of the right or left halves of the visual field of both eyes and usually occurs as a result of a middle cerebral or posterior cerebral artery stroke affecting either the optic radiation or visual cortex of the occipital lobe

Question 16

Internal Carotid Artery (ICA) Syndrome

What does it supply? What is most affected?

Answer 16

• Supplies both the MCA & ACA
• Occulusion typically results in large obstruction of areas supplied by MCA
• ACA has circulation from circle of Willis, but if absent, area supplied by ACA will also be affected

Question 17

Uncal Herniation

Answer 17

Inner part of the TEMPORAL Lobe has so much pressure -> herniates down & puts pressure on the BRAINSTEM

ICA Syndrome causes significant edema (common) which may INC ICP possibly leading to uncal herniation, coma, and even death

Question 18

What does the PCA supply?

(4)

Answer 18

1. Occipital lobe
2. Medial & Inferior Temporal Lobe
3. Upper brainstem (Midbrain)
4. Posterior diencephalon (most of thalamus)

Question 19

Posterior Communicating Artery

How does it perfuse the proximal PCA & how may that have an impact?

Answer 19

Occulsion is PROXIMAL to the psoterior communicating artery = minimal deficits

Occulsion is DISTAL to the posterior communicating artery = greater deficits

• Posterior Communicating artery allows for perfusion of the proximal PCA from either side

Question 20

Common Characteristics of PCA stoke…

Territory determines characteristics (6+

Answer 20

Peripheral Territory
1. Amnesia
2. Homonymous hemianopia (visual cortex affected)
3. Visal agnosia = difficulty w/ recognizing visual objects or ppl
4. Prosopagnosia = difficulty naming ppl on site (cannot recognize based on ppl’s facial features - NO problems with vision)
5. Dyslexia
6. Colouring naming & discrimination problems

Central Territory
1. Central post-stroke (thalamic) pain = burning & shooting - very severe & constant
2. Hemianesthesia = loss of sensation on one half of the body
3. Sensory impairment (all modalities - vision, smell, sight, touch)
4. Contralateral hemiplegia - paralysis
5. Oculomotor nerve palsy

Question 21

What does the Vertebral Artery supply?

Answer 21

Cerebellum & Medulla

Question 22

What does the Basilar Artery supply?

Answer 22

Pons, Internal Ear, & Cerebellum

Question 23

Common characteristics of a Vertebrobasilar Artery Syndrome?

Answer 23

1. Ataxia (ipsilateral)
2. Imparied sesnation over the face
3. Impaired pain and thermal sensation (contralateral)
4. Vertigo
5. Diplopia
6. Dysarthria
7. Dysphagia

5D, 3Ns

Typically affected by FORCEFUL neck mvmts (whiplash)

Question 24

Locked-In Syndrome (LIS)

Definition & Details

Answer 24

A condition in which a patient is aware and awale, but has complete paralysis of nearly all VOLUNTARY muscles in the body except for the eyes and are otherwise cognitively intact

• LIS is sudden onset
• Perserved consciousness and sensation
• Total locked-in syndrome: the eyes are paralyzed as well

Question 25

Lacunar Syndrome | Defintion, RF, Specifics

Answer 25

Caused by occulusions of small penetrating arteries supplying the brains deep structures. - 20% of all strokes - Strongly associated with HTN & DM - Higher corticol areas are perserved * Lacunar syndromes are consistent with specific anatomical sites - Pure motor lacunar stroke - Pure sensory lacunar stroke - Other lacunar syndromes: dyarthria/clumsy hand syndrome, ataxic hemiparesis, sensory/motor stroke, dystonia/involuntary mvmts

Question 26

Hemispheric Behavioral Differences: LEFT Lesions | (4)

Answer 26

1. Slow, cautious, anxious, and disorganized 2. Hesitant to try new tasks - requires more feedback, support, and encouragement 3. Aware of their deficits (may be why they are anxious) 4. Difficulties w/ communication and processing information in sequential linear order | * More likely to experience frequent and severe depression also

Question 27

Hemispheric Behavioral Differences: RIGHT Lesion | (4)

Answer 27

1. Quick, impulsive, poor judgement (safety risk) 2. Overestimates abilties. Unaware of their deficits (anosognosia) 3. Increased safety risk - feedback focused on slowing down, and recognizing risks and consequences of actions 4. Difficulties with spatial-perceptual taks and in grasping the whole idea of an activity or task

Question 28

RIGHT Parietal Cortex Lesions usually result in what dysfunction? May include disorders of (4) | Specific impairments also included

Answer 28

Perceptional Dysfunction 1. Body scheme: Internal awareness of the relationship of the body parts to each other and to the environment 2. Body Image: mental image and feeling of one's own body 3. Spatial Relations 4. Agnosia Specific impairments of body scheme/image - Unilateral neglect - Anosognosia - lack of insight into their condition - Somatagnosia - disorder of body awareness - Right-left discrimination - Finger agnosia - loss of ability to distinguish/name/recognize fingers

Question 29

Unilateral Neglect | Definition and Complications

Answer 29

Lack of awareness of parts of one's own body or of the external environment - Limited use of the more affected limbs - No reaction to sensory (visual, auditory, or somatosensory) stimuli presented on the more affected side **Almost always seen in RIGHT hemisphere lesions** - RT perceives both sides of the environment - LT only perceives the RT

Question 30

Difference between Hemianopia & Neglect?

Answer 30

Hemianopia = loss in visual field. Sense that it is not working - Fully aware of the deficit Neglect = no problems with vision BUT they cannot perceive it. Does not exist to them

Question 31

Stages of Motor Recovery: Stage 1

Answer 31

Flaccid paralysis

Question 32

Stages of Motor Recovery: Stage 2

Answer 32

Recovery begins. Spasticity begins. Development of minimal movement in synergies

Question 33

Stages of Motor Recovery: Stage 3

Answer 33

Voluntary control of movement synergies. Spasticity increased

Question 34

Stages of Motor Recovery: Stage 4

Answer 34

Spasticity begins to decrease. Some movement out of synergies

Question 35

Stages of Motor Recovery: Stage 5

Answer 35

Further decrease in spasticity. Movement almost independent of syngeries

Question 36

Stages of Motor Recovery: Stage 6

Answer 36

Disappearance of spasticity. Patterns of movement are near normal

Question 37

UE Spasticity is strong in: | (8)

Answer 37

1. Scapular retractors 2. Shoulder adductors depressors, & IR 3. Elbow flexors & forearm pronators 4. Wrist and finger flexors

Question 38

LE Spasticity is strong in:

Answer 38

1. Pelvic retractors 2. Hip adductors, extensors, and IR 3. Knee extensors 4. Plantarflexors and supinators 5. Toe flexors

Question 39

Pusher Syndrome

Answer 39

In the neck and trunk strong spasticity may cause increased lateral flexion to the hemiplegic side * Most likely to lean to unaffected side so they can WB

Question 40

Obligatory synergies w/ spasticity following a stroke | Definition - see chart on pg. 281

Answer 40

Patient is unable to perform an isolated movemetn of a single segmet without producing movement in the other segments of the same limb - Cannot disassociate - Synergisitic influence & voluntary control may vary from on limb to the other Review Obligatory Synergy Patterns - pg. 281