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| A) | It is useful to assess the severity of stroke. | ||
| B) | It is not intended to determine the cause of stroke. | ||
| C) | It was created for healthcare providers, to facilitate early clinical diagnosis and timely treatment of stroke patients. | ||
| D) | All the above |
When a patient is experiencing a stroke, time is of the essence. For every minute that passes, the brain loses critical blood flow and proper oxygenation. Frequently, the verbiage is "time lost is brain lost" [2]. This course will outline the NIH Stroke Scale and why its use is significant. Learners will be able to identify articles within the NIH Stroke Scale, perform the NIH Stroke Scale with proper scoring, and educate colleagues on the NIH Stroke Scale.
Stroke scales have evolved since the late 1980s. The first widely used scales included the Cincinnati Prehospital Stroke Severity Scale (CP-SSS), the Canadian Neurological Scale (CNS), the Edinburgh-2 Coma Scale, and the Oxbury Initial Severity Scale (OISS). With all of these, the greater the score, the larger infarct present. The NIH Stroke Scale (NIHSS) has evolved for the initial plan, which appeared in a naloxone trial for acute stroke [3].
| A) | 8 | ||
| B) | 11 | ||
| C) | 15 | ||
| D) | 20 |
The current NIHSS consists of 11 components, a decrease from the original 15. An even further modified form including only eight components was developed for quick assessments in emergency settings. For standard purposes, the 11-component NIHSS is the ideal tool [3,4]. The NIHSS was most recently updated in June 2016 [5].
| A) | Motor arm | ||
| B) | Facial palsy | ||
| C) | Blood pressure | ||
| D) | Level of consciousness |
As mentioned, the NIH stroke scale consists of 11 components [4,5]:
Level of consciousness (LOC)
LOC Instructions
LOC Questions
LOC Commands
Best gaze
Visual
Facial palsy
Motor arm
Motor leg
Limb ataxia
Sensory
Best language
Dysarthria
Extinction and inattention (formerly neglect)
Each component is paired with specific instructions, and scoring is based assessment of each section.
| A) | Items should be assessed in any order convenient for the examiner. | ||
| B) | The patient's performance can be rescored as the assessment progresses. | ||
| C) | The patient should be coached during the exam to ensure best performance. | ||
| D) | The score reflects how the patient performs the task, not how the provider perceives the performance. |
To obtain most accurate scoring with the NIHSS, the items should be assessed in the order listed. The patient's performance or response to each component should be fully recorded, and no items should be changed or rescored as the assessment progresses. The score is a reflection of how the patient performs the task or test, not how the provider perceives the patient performing each test. Ideally, the patient should not be coached during the exam [4,5].
| A) | Vertical gaze | ||
| B) | Circular gaze | ||
| C) | Diagonal gaze | ||
| D) | Horizontal gaze |
For this assessment, only horizontal gaze is tested and consists of voluntary and reflexive eye movements. If the patient has a conjugate deviation that can be overcome with voluntary or reflexive eye movements, the score will be recorded as a 1. If there is observed paralysis of cranial nerves III, IV, or VI, the score is also 1. In patients with ocular trauma, bandages, pre-existing blindness, or other disorders of visual acuity, testing with reflexive movements is recommended. Testing can be completed on all aphasic patients. This item is scored as follows [4,5]:
0: Normal
1: Partial gaze palsy; gaze is abnormal in one or both eyes, but forced deviation or total gaze paresis is not present
2: Forced deviation, or total gaze paresis is not overcome by the oculocephalic maneuver
| A) | 5 seconds | ||
| B) | 10 seconds | ||
| C) | 15 seconds | ||
| D) | 20 seconds |
When assessing function of the arms in patients with suspected stroke, the arms are extended with palm side down. If the patient is sitting, the arms are held at 90 degrees; if lying down, the arms are extended at 45 degrees. A pronator drift is scored greater than a 0 if an arm falls before 10 seconds on either side. Ideally, the arms are tested in turn, starting with the nonparetic side. A score of untestable (UN) should be made only if there is an amputation or joint fusion contributing to loss of function. The testing provider should also clearly document the reason for the UN score. This item is scored as follows [4,5]:
0: No drift; limb holds 90 (or 45) degrees for full 10 seconds
1: Drift; limb holds 90 (or 45) degrees, but drifts down before full 10 seconds without hitting the bed or other support
2: Some effort against gravity; limb cannot get to or maintain (if cued) 90 (or 45) degrees, drifts down to bed, but has some effort against gravity
3: No effort against gravity; limb falls
4: No movement
Untestable (UN): Amputation or joint fusion (provide further explanation)
| A) | Untestable | ||
| B) | Uncertain | ||
| C) | Unresponsive | ||
| D) | Uncooperative |
When assessing function of the arms in patients with suspected stroke, the arms are extended with palm side down. If the patient is sitting, the arms are held at 90 degrees; if lying down, the arms are extended at 45 degrees. A pronator drift is scored greater than a 0 if an arm falls before 10 seconds on either side. Ideally, the arms are tested in turn, starting with the nonparetic side. A score of untestable (UN) should be made only if there is an amputation or joint fusion contributing to loss of function. The testing provider should also clearly document the reason for the UN score. This item is scored as follows [4,5]:
0: No drift; limb holds 90 (or 45) degrees for full 10 seconds
1: Drift; limb holds 90 (or 45) degrees, but drifts down before full 10 seconds without hitting the bed or other support
2: Some effort against gravity; limb cannot get to or maintain (if cued) 90 (or 45) degrees, drifts down to bed, but has some effort against gravity
3: No effort against gravity; limb falls
4: No movement
Untestable (UN): Amputation or joint fusion (provide further explanation)
| A) | By asking the patient to sing a song | ||
| B) | By testing the patient's ability to write | ||
| C) | By having the patient describe images and read words/sentences | ||
| D) | By evaluating the patient's ability to understand complex instructions |
Assessment of language differs slightly from the other dimensions. The patient is asked to describe what is happening in the images from the NIH Stroke Scale manual (Figures 1 and 2) and to read from the list of words and sentences provided in the manual. The ability of the patient to perform the test is assessed based on the responses to these prompts as well as to all the commands in the preceding general neurological exam. If visual loss hinders the tests, the patient is asked to identify objects placed in the hand and to repeat and produce speech. Intubated patients should be asked to write, if able. Patients who scored a 3 on item 1a (i.e., responds only with reflex motor or autonomic effects, or totally unresponsive, flaccid, and areflexic) will automatically be scored with a 3 for this item as well. The examiner must choose a score for the patient with stupor or limited cooperation. A score of 3 should be used only if the patient is mute and does not follow one-step commands. This item is scored as follows [4,5]:
0: No aphasia; normal
1: Mild-to-moderate aphasia; some obvious loss of fluency or facility of comprehension, without significant limitation on ideas expressed or form of expression. Reduction of speech and/or comprehension, however, makes the conversation about provided materials difficult or impossible. For example, in a conversation about provided materials, the examiner can identify picture or naming card content from the patient's response.
2: Severe aphasia; all communication is through fragmentary expression; great need for inference, questioning, and guessing by the listener. The range of information that can be exchanged is limited; the listener carries the burden of communication. The examiner cannot identify the materials provided from the patient's response.
3: Mute, global aphasia; no usable speech or auditory comprehension
| A) | 1 | ||
| B) | 2 | ||
| C) | 3 | ||
| D) | 4 |
Adequate information to discover extinction and inattention may be acquired during the assessment of all of the prior dimensions. If the patient has severe visual loss preventing visual double simultaneous stimulation and cutaneous stimuli are normal, the score is recorded as normal (0). If the patient has aphasia but does appear to attend to both sides, the score is also normal. The presence of visual-spatial neglect or anosognosia may also be taken as evidence of abnormality. There is not an option to score UN for this item. This item is scored as follows [4,5]:
0: No abnormality
1: Visual, tactile, auditory, spatial, or personal inattention, or extinction to bilateral simultaneous stimulation in one of the sensory modalities
2: Profound hemi-inattention or extinction to more than one modality; does not recognize own hand or orients to only one side of space
| A) | Every 6 months | ||
| B) | Annually | ||
| C) | Every 2 years | ||
| D) | Every 5 years |
Training on administration of the NIH Stroke Scale is not mandatory for physicians; however, nurses who work in the emergency department, intensive care unit, or neurological unit are required to take training and to be certified through the NIH annually. This requirement is for facilities that are considered primary stroke centers (PSC) certified by The Joint Commission [9].