Stroke - A clinical talk

Naresh Mullaguri MDResident Physician

Department of Neurology

NIH STROKE SCALE AND t-PA

Objectives

Epidemiology

Types of Stroke

Clinical presentation

Evaluation

Management

Take home message

What is a Stroke?

1. Stroke is classified into two major types:

●Brain ischemia due to thrombosis, embolism, or systemic hypoperfusion

●Brain hemorrhage due to intracerebral hemorrhage (ICH) or subarachnoid

hemorrhage (SAH)

1. A stroke is the acute neurologic injury that occurs as a result of one of

these pathologic processes.

Epidemiology

➢ Globally, the incidence of stroke due to ischemia is 68 percent, while the incidence of

hemorrhagic stroke (intracerebral hemorrhage and subarachnoid hemorrhage

combined) is 32 percent, reflecting a higher incidence of hemorrhagic stroke in low-

and middle-income countries.

➢ In the United States, the proportion of all strokes due to ischemia, intracerebral

hemorrhage, and subarachnoid hemorrhage is 87, 10, and 3 percent, respectively.

The annual incidence of new or recurrent stroke is about 795,000, of which about

610,000 are first-ever strokes, and 185,000 are recurrent strokes.

➢ There is a higher regional incidence and prevalence of stroke and a higher stroke

mortality rate in the southeastern United States ("stroke belt") than in the rest of the

country .

➢ Age and Sex: Men have a higher incidence of stroke than women at younger but not

older ages, with the incidence reversed and higher for women by age 75 years and

older.

Types of Stroke

Subdural hemorrhage

Ischemic infarction

Intracerebral hemorrhage

Subarachnoid hemorrhage

Clinical

Presentation

1. Depends upon where the stroke is instead of how much area it involved.

2. In the ER, the patient is assessed with a standard tool called NIH(National Institute of Health) stroke scale.

Nuts and Bolts of NIH Stroke scale

1. Tool used by healthcare providers to

objectively quantify impairment caused by

stroke.

1. Initially designed as a research tool and

then incorporated into Acute stroke

evaluation.

1. A trained provider administers the NIHSS

which usually takes about 10 min.

1. Scale consists of 11 items and each item

ranges from 0-5 where 0 is normal and 5

means severely affected.

1. Maximum possible score is 42.

Score Stroke severity

0 No stroke

symptoms

1-4 Minor

Stroke

5-15 Moderate

Stroke

16-20 Moderate

to severe Stroke

21-42 Severe

Stroke

Performing the scale:

● Examiner should not coach the patient.

● Examiner may demonstrate the commands to patients that are unable to

comprehend verbal instructions, however the score should reflect the

patient’s own ability.

● For each item, the examiner should score the patient’s first effort and

repeated attempts should not affect the patient’s score. An exception to

this rule exist in the language assessment (item 9) in which the patient’s

best effort should be scored.

Components of NIH Stroke

scale

1. Level of Consciousness :

● It is a rough estimate of the extent of the location of the stroke and severity.

● Consciousness is affected when Brainstem, Thalamus and both cerebral cortices are affected. It is a complex phenomenon to explain but maintained by Ascending reticular activating system, thalamo-cortical projections.

● Patient can be alert, drowsy, Stuporous or comatose for which you score the points.

Level of

Consciousness

2. Able to answer questions

● What is the month?

● What is your age/date of birth?

3. Able to follow commands

● Close your eyes and open them

● Can you make a fist

Best

Gaze

- Extraocular muscle weakness

Cranial nerves or their nuclei in brainstem, EOM pathology

- Frontal eye field dysfunction

Middle cerebral artery infarction/frontal lobe hemorrhage, mass. Neurodegenerative diseases, Seizure or postictal state

Visual

fields

● Check all the quadrants and score for

1. Partial Hemianopia

2. Complete Hemianopia

3. Total blindness

Facial Palsy

1. 1. Minor facial palsy (Flattened

nasolabial fold, asymmetry on smiling

2. Partial paralysis (Total or near total

paralysis of lower face)

3. Complete paralysis of one or both sides

(absence of facial movement in the

upper and lower face)

Motor arm

0. No drift (45 - 90 degrees) after holding the

arm for complete 10 seconds

1. Drift but the arrm doesn’t hit the bed

2. Some effort against gravity - hits the bed but

has some antigravity strength

3. No effort against gravity - limb falls

4. No movement

UN. Amputation or Joint fusion

MOTOR LEG

0. No drift (30 degrees) after holding the arm for complete

5 seconds

1. Drift but the arrm doesn’t hit the bed

2. Some effort against gravity - hits the bed but has some

antigravity strength

3. No effort against gravity - limb falls

4. No movement

UN. Amputation or Joint fusion

Limb Ataxia

0. Absent

1. Present in one limb

2. Present in 2 limbs

UN Amputation or joint fusion

● To assess unilateral cerebellar lesion

● Eyes open

● Visual testing modifications

● The examining limb should not be disproportionately

weak

SENSORY

0. Normal

1. Mild to moderate sensory loss - pinprick feels dull

but still retains touch perception

2. Severe or total sensory loss - Patient is not aware

of being touched in the face, arm and leg

● Sensation or grimace to pinprick when tested

● Withdrawal to noxious stimuli in the obtunded or aphasic patient

● Stuporous or aphasic patients score 1 or 0. Quadriplegic patients score 2

● Brain stem stroke patients score 2 and comatose patients (1a = 3) score 2

BEST LANGUAGE

0. No aphasia

1. Mild to moderate aphasia

2. Severe aphasia

3. Global aphasia, Mute

Assessment is broken down to naming,

repetition, comprehension

DYSARTHRIA

0. Normal

1. Mild to moderate dysarthria

2. Severe Dysarthria

UN Intubated or other physical

barrier

EXTINCTION AND INATTENTION

0. No abnormality

1. Visual, tactile, auditory, spatial or personal

inattention or extiction to bilateral simultaneous

stimulation in one of the sensory modalities

2. Profound hemi-inattention or extinction to

more than one modality - doesn’t recognize one hand

or orients to one side of the space

LIMITATIONS OF NIH STROKE SCALE

1. Biased towards Left hemisphere

2. Poor predictor of Posterior circulation strokes

3. Cannot differentiate between the types of stroke

4. Can’t differentiate between acute ischemic stroke

from stroke mimics.

USES OF NIH STROKE SCALE

● Standardized and repeatable assessment of stroke patients utilized by large multi-

center trials.

● High levels of score consistency and reliability in inter-examiner and test-retest

scenarios.

● To evaluate the severity of acute stroke and to administer t-PA.

● History of scores can then be utilized to monitor the effectiveness of treatment

methods and quantify a patient’s improvement or decline.

● Prospective observational study used it to predict the outcome.

NIHSS and tPA eligibility

Scores between 5 - 24 Now trails have been going on to administer t-

PA for NIHSS <5 (minor but disabling stroke)

PRISM

Tissue Plasminogen activator

❖ Thrombolytic, commonly called “Clot buster”

❖ Administered through intravenous route

❖ Only FDA approved thrombolytic for the treatment of

acute ischemic strokes based on NINDS stroke trial in 1996.

(upto 3hrs from symptom onset)

❖ Administered upto 4.5 hrs of stroke symptom onset

(ECASS trial).

❖ 1 in 3 patients who received t-PA had complete resolution

tPA -MECHANISM OF ACTION

tPA

Inclusion

and

Exclusion

Criteria

A lot of revisions happened to the exclusion

criteria in 2015 based on the pooled meta-

analysis

tPA best evidence for smaller blood clots. For ICA and M1 division clots, revascularization rates were about 30%

Reperfusion

Hemorrhage

sICH occurs in about 2% of patients per ECASS III trial but in the NINDS trial 6% of patients had sICH.

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