Severity of an acute stroke
Measured Factor Disease
- More severe stroke
Measured Factor Detail
The NIHSS determines the severity of an acute stroke based on 15 items of consciousness, language, eye and hand control movement, extraocular movement, visual fields, facial palsy, motor strength, ataxia, sensation, aphasia, dysarthria, and inattention. A health care professional rates the patient’s ability to answer questions and perform activities. Rating for each item is scored. An items that can't be tested also has a score, e.g. patient with ambutation or joint fusion get 0 score for "limb ataxia" item. A higher score indicates a more severe stroke. A patient with a score ≤ 4 usually has favorable clinical outcomes.
Emergency Medicine Physician
Measured Factor High Impact
- Critical High: Scores ≥ 14
- Normal: Score 0
- Normal Adult Male: Score 0
- Normal Adult Female: Score 0
- Normal Geriatric Male: Score 0
- Normal Geriatric Female: Score 0
The NIHSS might not detect cognitive deficits and might underestimate the severity of neurological deficits from lacunar infarcts and cerebellar strokes. Another limitation of the score is lack of information on activity limitations such as difficulties with bed mobility, sitting, standing, walking, and upper limb function and on specific muscle strength to guide exercise prescription.
Study Validation 1
This retrospective study evaluated the use of the NIHSS to predict discharge arrangements in stroke patients admitted within 24 hours of symptom onset. Among 94 patients admitted to a university hospital from March through June 2000, 59% were discharged home, 30% were discharged to rehabilitation, and 11% were sent to long-term nursing facility. For each 1-point increase in NIHSS, the likelihood of going home was significantly reduced (odds ratio, 0.79; 95% confidence interval, 0.70 to 0.89, P<0.001). NIHSS scores of 5 or less were strongly associated with discharge home, whereas NIHSS scores from 6 to 13 were associated with rehabilitation, and NIHSS scores greater than 13 were associated with long-term nursing facility (P<0.001). The authors concluded that the NIHSS may predict care disposition for stroke patients to promote efficient use of health care resources.
Study Validation 2
This study evaluated the NIHSS scores at baseline (within 24-48 hours) and after 1 year in 377 patients within a municipality who had their first-ever non-subarachnoidal stroke during 1 year. At the 1-year follow-up, the Modified Rankin Scale was used in order to determine which patients were dependent. Logistic regression models were used to analyzed predictors of death and dependency. The median NIHSS score was 6 at baseline and 1 after 1 year, when 33% of the patients had died. After 1 year, of patients with NIHSS scores less than 4 at baseline, 75% were functionally independent, 17% were functionally dependent, and 8% were dead. Independent predictors of death were age, questions, commands, gaze, alertness and sensation. Independent predictors of dependency were age, commands, alertness and motor leg. The study concluded that NIHSS scores at baseline might predict the stroke outcome after 1 year. Age and reduced level of consciousness at baseline were associated with unfavorable outcomes after 1 year.
Study Validation 3
This retrospective study evaluated the use of the NIHSS in predicting clinically relevant poststroke dysphagia as compared with the Functional Independence Measure (FIM) test. Clinically relevant dysphagia was defined as aspiration on modified barium swallow or laryngeal penetration on modified barium swallow requiring diet change, or aspiration pneumonia. Of 290 patients admitted to acute stroke rehabilitation, 88 (30%) had clinically relevant dysphagia. Sensitivity, specificity, positive predictive value, and negative predictive value for the NIHSS were 75%, 62%, 46%, and 85%, respectively. For the FIM, these parameters were 80%, 72%, 55%, and 92%, respectively. The NIHSS >9 and FIM <55 were moderately predictive of clinically relevant dysphagia. The receiver operator characteristic curve showed slightly greater area under the curve with FIM than with NIHSS, indicating a slightly better sensitivity for FIM. However, the NIHSS has the advantage of being available earlier in the clinical course than FIM. Although the NIHSS may predicts dysphagia, it is not sensitive enough for use alone and may be combined with other dysphagia screenings in initial dysphagia management.
Study Additional 1
A National Institutes of Health Stroke Scale (NIHSS) score ≥12 might predict large-vessel occlusions (LVOs) for endovascular recanalization and might be used by prehospital providers such as helicopter emergency medical service providers. This study evaluated the utility of the NIHSS in predicting LVOs in patients with ischemic stroke transported by helicopter emergency medical services (HEMS) providers. NIHSS scores rated by HEMS providers were then compared with those rated by in-hospital stroke team physicians. Among 305 patients studied, 68.9% had LVOs. There was moderate agreement between HEMS providers and in-hospital physicians (72.1%; κ=0.571). Among patients presenting within 8 hours post-onset and NIHSS≥12, HEMS NIHSS had a sensitivity of 55.9% and positive predictive value of 83.7% in predicting LVO. The study concluded that HEMS providers can administer NIHSS with moderate to good agreement with the in-hospital stroke team.
Study Additional 2
This study determined clinical factors that predicted discharge destinations following acute stroke in the community of northern Manhattan. A group of 893 patients who survived first acute ischemic stroke were followed prospectively. NIHSS scores were categorized as mild (< or = 5), moderate (6 to 13), and severe (> or = 14). Polytomous logistic regression was used to determine clinical factors that predict rehabilitation, nursing home placement, or returning home. There were 611 (68%) patients who were discharged home, 168 (19%) to rehabilitation, and 114 (13%) to nursing homes. Patients who were sent to rehabilitation or nursing homes had moderate and severe neurologic deficits. Age over 65 and cognitive impairment were associated with placement to nursing home (age over 65: odd ratios, 2.4; 95% confidence interval, 1.0 to 5.6; cognitive impairment: odd ratios, 2.9; 95%, confidence interval 1.4 to 5.7), and rehabilitation (age over 65: odd ratios, 1.8; 95% confidence interval, 1.1 to 2.9; cognitive impairment: odd ratios, 2.9; 95% confidence interval, 1.4 to 5.7). The study concluded that severity of stroke is an important factor that influences discharge planning.