4 Stroke, part 1

Question 1

Definition of “Time of symptom onset”

Answer 1

The last known time when the patient’s condition was at their baseline (i.e., “last known well” time)
*Not the time a patient was discovered with symptoms”
Not the time of awakening (if symptoms were noted upon awakening)

Question 1

Top priority in stroke assessment

Answer 1

Assessment of airway, breathing, and circulation

Question 2

What is Todd’s paralysis?

Answer 2

Seizure/postictal paralysis
Transient paralysis following a seizure, which typically disappears quickly
Can be confused with a transient ischemic attack

Note that seizures can be secondary to a cerebrovascular accident.

Question 3

Blood glucose considerations in some of the prehospital stroke scales

Answer 3

Los Angeles Preshospital Stroke Screen
60- 400 mg/dL
Melbourne Ambulance Stroke Screen
50-400 mg/dL

Question 4

Most widely used scale for documenting the severity of a stroke

Answer 4

National Institute of Health Stroke Scale (NIHSS)
- weighted toward the detection of anterior circulation strokes
- has a bias toward detection of left hemisphere strokes

Question 5

Important scoring rules for proper use of the NIHSS

Answer 5

1. Score what you see, not what you think
2. Score the first response, not the best response (except in item 9, best language)
3. Do not coach

Question 6

Components of the NIHSS

Answer 6

1a Level of consciousness [LOC] (3)
1b LOC questions (2)
1c LOC commands (2)
—-
2 Best gaze (2)
3 Visual (3)
4 Facial Palsy (3)
—-
5a Motor arm, left (4)
5b Motor arm, right (4)
6a Motor leg, left (4)
6b Motor leg, right (4)
—-
7 Limb ataxia (2)
8 Sensory (2)
9 Best language (3)
10 Dysarthria (2)
11 Extinction and inattention (2)

Question 7

Interpretation of the NIHSS score

Answer 7

0 - No stroke symptoms
1-4 - minor stroke
5-15 - moderate stroke
16-20 - moderate-to-severe stroke
21-42 - severe stroke

Question 8

Remarks on anterior cerebral artery (ACA) infarction

Answer 8

Causes contralateral sensory and motor symptoms in lower extremity, with sparing of the hands and face

Question 9

A left-sided ACA lesion is tyipcally associated with

Answer 9

akinetic mutism and transcortical motor aphasia (a nonfluent aphasia with greatly reduced spontaneous speech, but with retained autidory comprehension and repetition ability)

Question 10

a right-sided ACA lesion is typically assocaited with

Answer 10

confusion and motor hemineglect

Question 11

most commonly involved vessel in stroke

Answer 11

Middle cerebral artery (MCA)

Question 12

Remarks on dominant hemisphere

Answer 12

In right-handed patients and in up to 80% of left-handed patients, the left hemisphere is dominant.

If the dominant hemisphere is involved, aphasia (receptive, expressive, or both) is often present.

Question 13

If the nondominant hemisphere is involved, this may occur

Answer 13

inattention, neglect, extinction, dysarthria without aphasia, and constructional apraxia

Question 14

Classic symptoms of posterior cerebral artery (PCA) stroke

Answer 14

(distal posterior circulation stroke)
Ataxia
Nystagmus
Altered mental status
Vertigo

Question 15

This may indicate a brainstem lesion

Answer 15

Crossed neurologic deficits (e.g., ipsilateral cranial nerve deficits with contralateral motor weakness)

Question 16

Remarks on basilar artery occlusion

Answer 16

(middle posterior circulation stroke)
most common presenting signs/symptoms are
- unilateral weakness
- cranial nerve VII signs
- dysarthria
- Babsinki sign
- oculomotor signs
- dizziness
- Horner’s syndrome
- Locked-in syndrome (rarely)
Basilar artery occlusions have high risk of death and poor outcomes

Question 17

Remarks on locked-in syndrome

Answer 17

Can occur rarely in basilar artery strokes
Occrs with bilateral pyramidal tract lesions in the ventral pons
Characterized by complete muscle paralysis except for upward gaze and blinking

Question 18

Remarks on vertebrobasilar infarction

Answer 18

(Proximal posterior circulation stroke)
may present with unilateral cranial nerve V symptoms
Horner’s syndrome

Question 19

Remarks on cerebellar infarction

Answer 19

1. Up to 25% of noncontrasted head CT is unremarkable. Hence, obtain an emergent diffusion-weighted MRI when this diagnosis is suspected
2. Rapid deterioration may occur due to increased brainstem pressure from cerebellar edema. Serially examine for gaze palsy and altered mental status.
3. Obtain early neurosurgical consultation for patients with cerebellar infarction for possible emergency posterior fossa decompression

Question 20

Remarks on lacunar infarction

Answer 20

1. Lacunar infarcts are pure motor or sensory deficits caused by infarction of small penetrating arteries
2. Commonly associated with chronic hypertension and incrasing age
3. Prognosis is generally considered more favorable than for other stroke syndromes

Question 21

Remarks on cervical artery dissection

Answer 21

1. Consists of carotid and vertebral artery dissection
2. Major cause of stroke in young adults and the middle-aged
3. A history of *neck trauma in the days to weeks prior to presentation is a prominent risk factor

**(the trauma is usually minor, such as manipulative thearpy of the neck or sport-related trauma)*

Question 22

Cervical artery dissections’ typical first symptom

Answer 22

unilateral *headache (68%), neck pain (39%), or face pain (10%)
*headache in carotid artery dissection is most commonly frontotemporal and may mimic SAH (thunderclap)
*headache in vertebral artery dissetion is typically occipital

Question 23

Diagnostic modalities of choice for suspected cervical artery dissections

Answer 23

CT/CT angiography and MRI/magnetic resonance angiography

Question 24

Treatment of cervical artery dissection

Answer 24

Treated similarly to any other stroke patient (i.e., *thrombolysis, antiplatelet/anticoagulation)

**no increased incidence of harm*

Question 25

Remarks on SAH

Answer 25

1. Typically characterized by severe occipital or nuchal thunderclap headache
2. May be associated with activities with a Valsalva maneuver, such as defecation, sexual activity, weight lifting, or coughing, at stroke onset