NIHSS : Diagnostic Tool and Challenges

Primary Objectives To become familiar with components of the NIH Stroke Scale To understand the rationale for NIH Stroke Scale score use in acute stroke patient evaluation To understand the limitations of the NIHSS

Goal of Stroke Scale Must be brief “Time is Brain” – Estimated 1.9 million neurons are lost in each minute of ischemia • Should focus on aspects that are informative and can be predictive of outcome • Scales developed to be used in trials and clinical practice – Reliable, valid – Predictive potential

Why Use the NIHSS Standardized stroke severity scale to describe neurological deficits in acute stroke patients •Allows us to: Quantify our clinical exam Determine if the patients’ neurological status is improving or deteriorating Provide for standardization Communicate patient status

NIHSS LOC Best gaze Visual field testing Facial paresis Arm & leg motor function Limb ataxia Sensory Best language Dysarthria Extinction & inattention

How to Increase Accuracy of NIHSS • The most reproducible response •Do not coach patients unless specified in the instructions •Some items are scored only if definitely present •Record what the patient does, not what you think the patient can do

NIHSS 1a. Level of Consciousness(LOC) Arousal Status Alert (or awakens easily and stays awake) 0 Drowsy (Responds to minor stim. but falls back asleep) 1 Obtunded (Responds only to deep pain or vigorous stim) 2 Comatose (No response) Telestroke exam: no need to discuss LOC unless patient is comatose

NIHSS 1b. LOC- Questions Month? Age? Both questions answered correctly 0 One question answered correctly 1 Neither question answered correctly 2 1c. LOC– Commands Opens/closes eyes Opens/closes hands Both commands performed correctly 0 One command performed correctly 1 Neither command performed correctly 2

NIHSS Best to ask questions from the patient’s unaffected side

NIHSS 2. Eye Movements: Horizontal eye movements Normal 0 Mild gaze paralysis (can bring eyes only over to midline) 1 Complete gaze paralysis (deviated & unable to bring eyes over) 2 3. Visual fields: Sees objects in Four quadrants Partial hemianopia (upper OR lower quadrant) 1 Complete hemianopia (upper AND lower quadrants) 2 Bilateral hemianopia (total blindness) 3

NIHSS If patient is confused, aphasic or otherwise altered sensorium: go to each side of bed and call name to try and get patient to look to you If patient is obtunded, hold eyes open and slowly rock head back and forth as though nodding ‘no’. Eyes that rock back and forth is normal response. Rocking to one side only is score of 1 and no movement is score of 2.

NIHSS 4. Facial: Facial movements Normal 0 Minor paralysis (flattening of nasolabial folds) 1 Partial paralysis (near or total paralysis lower face) 2 Complete paralysis (Of upper and lower face) 3 5a. Motor – Left Arm Hold arm straight out from chest Normal (No drift at all) 0 Drift (Drifts downward but NOT to bed before 10 sec.) 1 Drifts to bed within 10 sec 2 Movement, but not against gravity 3 Complete paralysis (No movement at all) 4 Amputation or joint fusion (N/A)

NIHSS For aphasic patient, smile at patient in attempt to get them to smile, or say “you do it” and point to your smile and then their face. Same with extremities. Hold your arm out so they can see it while raising their arm or leg and say “you do it” or even repeat “up”

NIHSS 7. Limb Ataxia Finger-Nose ,Heel-Knee-Shin Absent (no ataxia, OR pt cannot move arm/leg) 0 Present in one limb 1 Present in two or more limbs 2 (is absent if patient cannot understand or is too weak to do) 8. Sensory Hemisensory loss: (Test on face, arm & thigh) Normal, no sensory loss 0 Mild to moderate loss 1 Severe to total sensory loss (unaware of being touched) 2

NIHSS Don’t waste time if they can’t comprehend task. Watch general limb movement. If they can rub an eye or scratch without difficulty, there is no ataxia. Only score if you see ataxia. Ataxia is one of the less reliable tests of the NIHSS

NIHSS 9. Language/Aphasia Naming, Reading. Fluency Normal ability use words and follow commands 0 Mild to Moderate (Repeats / names with some difficulty) 1 Severe Aphasia (very few words correct or understood) 2 Mute (no ability to speak or understand at all) 3 10. Dysarthria (slurred) Speech clarity (slurring) Normal 0 Mild to moderate slurred speech (some or most) 1 Severe (unintelligible - none understandable) 2 Intubated or other physical barrier (N/A)

NIHSS If they can’t see the page, make sure they are wearing any glasses they may have. If they still can’s see, pull out your glasses or a pen and ask what it is. For subparts, point to pen clip, ball point, lens or frame.

NIHSS 11. Neglect Ignores touch or vision to one side No abnormality 0 Mild (either visual or tactile – partial neglect) 1 Profound (Visual and tactile – complete neglect) 2

NIHSS To ensure a sensitive test, need to emphasize the unaffected side prior to testing both sides. You don’t need to waste time testing is the patient clearly responds to stimuli on one side only. This is evidence of severe neglect .

NIHSS The most unreliable parts of the NIHSS are ataxia, facial weakness, visual loss. NIHSS is not very sensitive to vertebral artery stroke which may present with nausea, vomiting, nystagmus and perhaps neck pain. NIHSS is not sensitive to isolated cognitive loss such as inability to calculate Consider rapid MRI to evaluate these patients. MRI has high sensitivity for acute infarct, though not 100% CT angiography has high sensitivity and specificity for large vessel stenosis or occlusion.

NIHSS and Severity of Ilness Total scores range from 0-42 with higher values representing more severe infarcts >25 Very severe neurological impairment 15-24 Severe impairment 5-14 Moderately severe impairment <5 Mild impairment Adams, HP, et al. (1999). Neurology: 53: 126-131. •

NIHSS and Outcomes Initial score of 7 was found to be important cut-off point NIHSS >7 demonstrated a worsening rate of 65.9%. NIHSS <5 most strongly associated with D/C home • NIHSS 6-13 most strongly associated with D/C to rehab • NIHSS >13 most strongly associated with D/C to nursing facility – (Schlegel et al., 2003)

Symptoms of Stroke Sudden Onset: Numbness or weakness of face, arm or leg, especially on one side of the body Confusion, trouble speaking or understanding Trouble seeing in one or both eyes Trouble walking, dizziness, loss of balance or coordination Severe headache with no known cause

Stroke Is a Medical Emergency Call 911! If you notice one or more of the warning signs for stroke, GET HELP IMMEDIATELY!