From the Guidelines
The National Institutes of Health Stroke Scale (NIHSS) score of less than 8 is not exactly classified as a mild stroke, but rather a score of 0-5 is considered mild neurological dysfunction, as indicated by the Valve Academic Research Consortium 3 1. This classification is based on the updated endpoint definitions for aortic valve clinical research, which provides a framework for assessing stroke severity. The NIHSS evaluates 11 different aspects of neurological function, with a total possible score ranging from 0 (no deficits) to 42 (severe stroke). According to the study, mild neurological dysfunction is defined as an NIHSS score of 0-5, moderate neurological dysfunction is defined as an NIHSS score of 6-14, and severe neurological dysfunction is defined as an NIHSS score of 15 or higher 1. The guidelines for the early management of adults with ischemic stroke also emphasize the importance of using a stroke rating scale, such as the NIHSS, to assess stroke severity and guide treatment decisions 1. However, the most recent and highest quality study, Valve Academic Research Consortium 3 1, provides the most accurate definition of mild stroke, which is an NIHSS score of 0-5. Therefore, an NIHSS score of less than 8 should be considered in the context of the patient's overall clinical presentation, and treatment decisions should be guided by the most recent and highest quality evidence 1. Some key points to consider when assessing stroke severity include:
- The NIHSS score is an important prognostic factor, with higher scores indicating more severe neurological deficits and poorer outcomes
- The classification of stroke severity is critical for guiding treatment decisions, including the use of thrombolytic therapy and rehabilitation strategies
- The Valve Academic Research Consortium 3 provides a framework for assessing stroke severity, with mild neurological dysfunction defined as an NIHSS score of 0-5 1
From the Research
Classification of Mild Stroke
A National Institutes of Health Stroke Scale (NIHSS) score of less than 8 is classified as a mild stroke due to several factors:
- The NIHSS score is a valid assessment tool used to determine the severity of a stroke and predict outcomes 2, 3, 4, 5, 6.
- Studies have shown that patients with low NIHSS scores (less than 8) are more likely to have favorable outcomes, but a significant proportion may still have unfavorable outcomes 2, 3, 5.
- The definition of a minor stroke has been proposed to be an NIHSS score of 0-3 or 0-5, with some studies suggesting that an NIHSS score of 1 or less is associated with a high likelihood of favorable outcome 3, 5.
- Individual items of the NIHSS, such as motor impairment, have been shown to be associated with poor outcomes, highlighting the importance of considering all aspects of the NIHSS score when making treatment decisions 3, 6.
Predictors of Outcome
Several factors have been identified as predictors of outcome in patients with mild stroke, including:
- Age: older patients are more likely to have poor outcomes 3.
- Baseline NIHSS score: higher scores are associated with poorer outcomes 2, 3, 4, 5.
- Individual NIHSS items: certain items, such as motor impairment, are associated with poor outcomes 3, 6.
- Comorbidities: presence of comorbidities, such as hypertension and diabetes, may affect outcomes 4.
Treatment Decisions
The decision to withhold treatment in patients with mild stroke should be made with caution, as the types of neurological deficits may not justify withholding treatment 6.
- Studies have shown that a significant proportion of patients with low NIHSS scores may still have unfavorable outcomes, highlighting the importance of considering all aspects of the patient's condition when making treatment decisions 2, 3, 5.
- The use of thrombolytic therapy and other treatments should be considered on a case-by-case basis, taking into account the patient's individual circumstances and the potential benefits and risks of treatment 2, 3, 6.