Stroke Acute Care & Unilateral Spatial Neglect & Pusher Syndrome Flashcards
(42 cards)
1
Q
All patients admitted to hospital with suspected acute stroke should receive brain imaging evaluation on arrival to hospital. In most cases, noncontrast CT (NCCT) will provide the necessary information to make decisions about acute management (True/False)
A
- True
2
Q
What is required before initiation of IV alteplase (tPA) in most patients
A
- Non-constrast head CT
- Glucose
3
Q
What does not need to have resulted prior to IV tPA initiation if there is no suspicion for underlying coagulopathy
A
- International normalized ratio (INR)
- Partial thromboplastin time (PTT)
- Platelet count
4
Q
Centers should attempt. to obtain non-contrast CT within______ of arrival in ≥50% of stroke patients who may be candidates for IV tPA or mechanical thrombectomy
A
- 20 minutes
5
Q
When should IV tPA be administered for all eligible acute stroke patients
A
- Within 3 hrs of last known normal & to a more selective group within 4.5 hrs of last known normal
- Centers should attempt to achieve door to needle times of <60 min in ≥50% of stroke patients treated with IV tPA
6
Q
What should BP be maintained at after IV. alteplase treatment
A
- BP should be maintained <180/105 mmHg for at least the first 24hrs afterwards
7
Q
Describe mechanical thrombectomy
A
- For candidates, an urgent CT angiogram or MR angiogram (to look for large vessel occlusion) is recommended but should not delay treatment with IV tPA if indicated
- Should be initiated ASAP
8
Q
Patients ≥18 years should undergo mechanical thrombectomy with a stent retriever if they:
A
- Have minimal prestroke disability
- Have a causative occlusion of the internal carotid artery or proximal middle cerebral artery
- Have a National Institutes of Health stroke scale score of ≥6
- Have a reassuring noncontrast head CT (ASPECT score of ≥6)
- If they can be treated within 6 hours of last known normal. No perfusion imaging (CT-P or MR-P) is required in these patients
9
Q
Describe unilateral spatial neglect
A
- Most widely quoted definition of neglect is a description of the resulting behavioral disabilities: fails to report, respond, or orient to novel or meaningful stimuli presented to the side opposite a brain lesion
- This definition does not describe the causal mechanism of neglect but indicates that it is not simply due to sensory or motor defects
10
Q
Hemianopsia/visual field cut screening
A
- Complains of having difficulty seeing items or state the inability to find things
- Miss details in one visual field
- Locate lost items once cued to the location
- Attempt to make eye contact during conversations, regardless of where the therapist stands
- Spontaneously use both UE when needed for a task
- Spontaneously compensate for loss of vision by turning head
11
Q
Spatial neglect screening
A
- Miss details in one visual field
- Walk/propel into things on one. side without noticing
- Loss track of limbs, letting them fall off footrests or table without repositioning
- Seem to forget position of affected hand & drop or spill. items
12
Q
Implications of unilateral spatial neglect (USN)
A
- Associated with poor functional outcomes & long stays in hospitals & rehab centers
- Predispose pts to the risk of falls & to semi permanent or permanent wheelchair use
- Can reduce QOL compared with that of other stroke pts who do not have USN
13
Q
What are the terms used in clinical practice for USN
A
- Visual neglect
- Motor neglect
- Hemineglect
- Inattention
- Stroke may differentially affect our ability to direct our attention in the visual, auditory, or tactile modalities
14
Q
What are the 3 types of USN
A
- Personal neglect: neglect of one side of the body
- Near extrapersonal: neglect of the environment within reaching distance
- Perceptual: unable to perceive or attend to contralateral space; neglect of environment beyond reaching distance
15
Q
When is contralesional neglect occur more. often (left or right hemisphere stroke)
A
- More often after right hemisphere stroke
16
Q
USN can occur with a lesion in what areas
A
- Attention is mediated by a network of many different anatomic areas working together
- Posterior parietal cortex: interconnections with premotor cortex
- Frontal lobe: eye fields, superior colliculus, & paralimbic areas
- Cingulate gyrus: strongest interconnection b/w posterior parietal lobe & paralimbic areas
- Striatum
- Thalamus
17
Q
Categories of USN
A
- Memory & representational deficits
- Action intentional disorders (motor neglect): not a deficit of motor pathway but a failure or decreased ability to move in the contralesional space despite being aware of a stimulus in that space
- Inattention (sensory neglect): lack of/decreased awareness of sensory stimulation in the contralesional hemispace; occurs even though the sensory pathways & primary sensory cortical areas are intact
18
Q
Tests for USN
A
- Catherine Bergego Scale (CBS): behavioral assessment of neglect
- Albert’s Cancellation Test
- Single letter Cancellation Test
- Bell Cancellation Test
- Clock Drawing Test
- Line Bisection Test
19
Q
Describe Albert’s cancellation test
A
- Patient is directed to make a slash through each hash mark (\ or/) to make an X
20
Q
Describe Single Letter Cancellation Test
A
- Give patient a paper in midline with 6 lines of 52 capital letters in each line including 104 H’s
- Ask patient to scan the letters & draw a line through the letter H each time it appears
- Because there are 53 H’s on the left & 51 H’s on the right the tester can determine neglect & which side it’s on
- > 4 omissions of the letter H is considered pathological
21
Q
Describe Bell Cancellation Test
A
- The objects are presented in an apparently random order, but are actually equally distributed in 7 columns containing 5 targets and 40 distractors each.
- There is a black dot on the bottom of the page to indicate where the page should be placed in relation to the patient’s midsaggital plane
- Of the 7 columns, 3 are on the left side of the sheet, 1 is in the middle, and 3 are on the right
- If the patient omits to circle bells in the last column on the left, we can estimate their neglect is mild. However, omissions in the more centered columns can suggest a greater neglect of the left side of space.
- The total number of circled bells is recorded as well as the time taken to complete. The maximum score is 35.
An omission of 6 or more bells on the right or left half of the page indicates USN; Judging by the spatial distribution of the omitted targets, the evaluator can then determine the severity of the visual neglect and the hemispace affected (i.e. left or right) - The sequence by which the patient proceeds during the scanning task can be determined by connecting the bells of the scoring sheet according to the order of the numbering
22
Q
Describe the Clock Drawing Test
A
- Instructions given to pt: I would like you to draw a clock, put in all the numbers & set the hands for 10 after 11
- Following this condition the patient should be instructed to copy as accurately as possible a clock from a model
23
Q
Describe the Line Bisection Test
A
- Patient is instructed to place a mark with a pencil thorugh the center of a series of horizontal lines
- Usually a displacement of the bisection mark towards the side of the brain lesion is interrupted as a symptom of neglect
24
Q
Cognitive rehab for USN
A
- Restitutive approach: aim to. alter the underlying cognitive impairment; more often used in early stage of stroke when plasticity is thought to be greatest
- Compensatory approach: emphasis on coping with & finding ways of adapting to existing impairments; more often used in later stages of stroke
25
Neglect interventions (top-down versus bottom-up)
- Top-down: requires awareness of the disorder; aim to train the person to voluntarily compensate for their neglect; methods include training in scanning & usually provide feedback; focus on the level of disability rather than impairment
- Bottom-up: do not require awareness of the disorder; aim to modify underlying. factors; prism wearing & prism adaptation training are popular recent examples of bottom-up approach; eye patching & use of devices to stimulate the neglected side
26
Non-pharmacological interventions for USN
- Visual Scanning Training: Lighthouse Technique, Anchors, Guides, Turns
- Right half-field eye-patching
- Mirror therapy
- Prism adaptation
- Left-hand somatosensory stimulation with visual scanning training
- Contralateral transcutaneous electrical nerve stimulation and optokinetic stimulation
- Trunk rotation
- Repetitive transcranial magnetic stimulation
- Galvanic vestibular
- Dressing practice
27
Pharmacological intervention for USN
- Dopamine agonists: improve tests of visuospatial neglect like line bisection, letter cancellation, & reading
- Noradrenergic agonists: improves on paper & pencil tasks and visual exploration
- Pro-cholinergic drugs: increase levels of acetylcholine & enhance the function of neural cells
- Acetylcholinesterase inhibitors: may improve rehab outcomes by enhancing cognitive functioning & reducing apathy thereby increasing participation & enhancing the ability to learn during rehab
28
Describe lateropulsion
- Active lateral tilt of the body
- Misperception of postural verticality with an involuntary tendency to drift or fall to one side when positioned upright
- Usually ipsilateral in caudal brainstem strokes
- Usually contralesional in rostral brainstem strokes as well as in hemisphere strokes
29
Why does lateropulsion happen
- Could result directly from a pathological asymmetry of motor function or tone
- Could be an attempt to align the body with an internal vertical references which is erroneously perceived to be tilted from true earth vertical
30
Describe pushing behavior
- Push strongly towards his hemiplegic side in all positions & resist any attempt at passive correction of his posture; that is correction which would bring his weight towards or over the midline of his body to the unaffected side
31
Why does pushing behavior happen
- Altered sense of postural verticality
- Pushing might result from a mismatch b/w a normal visual perception of the vertical & an ipsilesional tilt in the perception of the postural vertical
- Pushing & lateropulsion could be a clinical manifestation of stilted representation of the vertical whereby pushers actively align their body with a tilted reference of verticality
32
What is the continuum in verticality perception after stroke
- Patients w/o lateropulsion should show a normal verticality perception
- Those with a lateropulsion but no pushing show moderate biases in verticality perception
- Those with lateropulsion plus pushing show the most severe tilts in verticality perception
33
Describe verticality
- Visual perception of the vertical that relies on visuovestibular information
- Postural perception of the vertical derived from graviceptive somesthetic information: R. hemisphere plays a predominant role in the perception of postural vertical
- Tactile (haptic) vertical
34
What will individuals with pusher syndrome may have
- Primary visual or visual perceptual problems
- Impaired proprioception
- Motor impairments
- All which leave them less equipped to relearn posture & balance
35
Describe Pusher syndrome
- Pushing actively with nonparetic extremities to the side contralateral to the brain lesion, which is termed “contraversive pushing,” differentiates the clinical picture of pusher syndrome from the loss of equilibrum that can occur in other patients with hemiparesis
- Contraversive pushing frequently occurs when left-sided neglect is present after lesions of the right hemisphere
- Pusher syndrome frequently occurs also with lesions of the left hemisphere and is not related to neglect but rather to aphasia
- Neither neglect nor aphasia, however, is causally related to contraversive pushing
36
What brain structure is typical damaged in patients with Pusher syndrome and causes what
- Left & right posteriolateral thalamus
- They perceive postural vertical to be an average of 18º toward the side of the lesion
- Processing of visual & vestibular inputs for the determination of visual vertical is unaffected by the lesion
- When sat upright they experience a mismatch b/w visual vertical & perception of postural vertical
37
Slide 46
38
Prognosis for Pusher syndrome
- Only 6 mo after stroke pathological pushing behavior is rarely still evident
- Pusher syndrome thus has a good prognosis & does not seem to negatively influence the outcome of rehab
- Patients with contraversive pushing take 3.6 wks longer than pts w/o pusher. syndrome to reach the same functional outcome level
39
Slides 50-55
40
Treatment concepts for Pusher syndrome
- Preserved ability of patients with contraversive pushing to align the body axis to earth-vertical with the help of visual cues from the environment and speculated that this might be a useful rehabilitation tool.
- Patients with pusher syndrome are typically unable to spontaneously use visual input to control upright body posture, the use of visual cues from the environment may be an effective training tool when combined with conscious strategies for the achievement of postural control
- The recovery process for patients with pusher syndrome post-stroke has been found to be slow, requiring longer than average to reach a level of independence in activities of daily living and ambulation
41
Pusher syndrome is the same as contraversive pushing but not the same as lateropulsion (True/False)
- True
42
Slide 57-59
