Relevance of Non-Contrast Computed Tomography (NCCT) Based Alberta Stroke Program Early CT Score (ASPECTS) in Predicting Severity of Acute Ischemic Stroke at Presentation and Its Functional and Cognitive Outcome at 90 Days

  

    
Variable
    
Beta coefficient
    
Standard error
    
P value
    
Odds ratio
    
Odds ratio Lower bound    (95%)
    
Odds ratio Upper bound    (95%)
  
  

    
Aspects score
  
  

    
>=6
    

    

    

    
1.000
    

    

  
  

    
<6
    
1.925
    
0.916
    
0.036
    
6.855
    
1.137
    
41.313
  

Table 6.4: Univariate logistic regression of ASPECTS score to affect MOCA at 90 days(<26).

Discussion

The study with a prospective observational design was conducted over a period of one year and three months at the Department of Neurology, ABVIMS and Dr RML Hospital, New Delhi. 35 patients above 18 years of age with acute ischemic stroke presenting within 48 hours of symptom onset and meeting the defined inclusion and exclusion criteria were included in the study. The mean age of study was 55.14 years with a standard deviation of 12.4. The gender distribution in the study cohort indicated male population of 54.29% and female population of 45.71 %. The gender distribution in the study thus came out to be balanced. Majority of the subjects were in the age group of 51-60 years and majority being male subjects. 65% patients with ischemic strokes are usually above the age of 65 as per studies [5]. The distribution of risk factors among the study participants provided valuable insights into the potential contributors to stroke incidence. Diabetes emerged as the most prevalent risk factor, affecting 57.14% of the individuals, followed by hypertension at 45.71%; other causes included smoking (14.29%), alcohol consumption (5.71%), dyslipidemia (8.57%), rheumatic heart disease (11.43%) and non-valvular atrial fibrillation (2.86%). 54.29% of the study population had Left MCA territory infarcts while 45.71% had infarcts in the Right MCA territory. In a patient by Ng YS et al, of 2213 stroke patients, anterior circulation strokes were twice as much common as posterior circulation strokes and of the anterior circulation strokes, 51% had MCA involvement [6]. In the study 68.57% of the subjects presented with NIHSS scores ranging from 5 to 15, indicating a moderate level of stroke severity, 20.00%, had mild strokes with NIHSS scores less than 5, while 11.43% exhibited moderately severe strokes with scores falling within the 16 to 20 range. The mean NIHSS score at presentation was 8.06 ± 4.26. The ASPECTS at the time of presentation revealed a predominantly lesser severity, with 77.14% of individuals presenting with ASPECTS scores equal to or greater than 6. In contrast, 22.86% of the cases had ASPECTS scores below 6, suggesting extensive involvement of brain regions. The mean ASPECTS score at presentation was 7.14 ± 2.49, reflecting the overall severity of early CT findings. The length of hospital stay for individuals with stroke predominantly falls within a short duration, with 77.14% of cases having stays of less than 7 days. Conversely, 22.86% of patients experienced a longer hospitalization period of 7 days or more. The mean length of hospital stay was 4.71 ± 2.94 days, reflecting a relatively shorter overall duration. The functional outcomes of individuals post-stroke, as measured by the mRS at 90 days, indicated a favorable recovery overall. The mean mRS score was 1.43 ± 1.2. 20 patients (57.14%) had mRS less than 2 while 15 patients (42.86%) had mRS greater than or equal to 2 at 90 days. The relatively low mean suggests a generally positive trend in functional recovery three months after the stroke event. In our study when the effect of TOAST classification on mRS at 90 days was assessed, no particular TOAST group having worst outcome could be found. For LVD, 50% had mRS <2 and 50% had mRS ≥2 while for SVD, 83.33% had mRS <2 and 16.67% had mRS ≥2. For Embolic group, 25% had mRS <2 and 75% had mRS ≥2. Studies have shown that large vessel occlusion followed by cardioembolic stroke occluding large vessels have poor outcome when followed up at two months to one year time period [7]. The assessment of participants' cognitive function using MoCA at 90 days post-stroke revealed encouraging findings. Majority (80.00%) demonstrated cognitive performance at or above 26, indicating a favourable cognitive outcome. The mean MoCA score of 27.86 ± 2.53 further supports the overall cognitive well-being of the study population. The assessment of specific cognitive domains MoCA at 90 days post-stroke provides valuable insights into the participants' cognitive profiles. The distribution of scores across different domains indicates varying patterns of cognitive function. Notably, the majority of participants demonstrated disability in naming (34.29%) and language (28.57%), while memory, attention, abstract thinking showed no impairment in our study. Recall domains, Visuospatial/executive function, orientation domains also exhibited relatively lower frequencies of impairment. This comprehensive evaluation contributed to a nuanced understanding of the cognitive outcomes following stroke, highlighting areas of both strength and potential challenges in the studied population. There was no significant difference noted in the final MoCA score depending on whether left or right MCA territories have been involved. However, deficits in visuospatial and executive domains were found to be more in right MCA strokes while naming and language were involved more in left MCA strokes. In our study an attempt was made to correlate MoCA scores at 90 days for patients with different stroke types based on TOAST classification. For LVD, 16.67% had MoCA <26 and 83.33% had MoCA ≥26 while for SVD all (100%) had MoCA ≥26. For Embolic, 50% had MoCA <26 and 50% had MoCA ≥26 while for strokes of other eitiologies, 33.33% had MoCA <26 and 66.67% had MoCA ≥26. Cognitive worsening (MoCA <26) was most pronounced in the Embolic group, with 50% scoring below 26. (p value 0.027) According to our study there is significant moderately negative correlation between ASPECTS score at presentation and NIHSS at presentation with correlation coefficient of -0.452. There was also significant strong negative correlation between ASPECTS score at presentation and length of hospital stay (in days) with a correlation coefficient of -0.632. There was also significant strong negative correlation between at presentation ASPECTS and mRS at 90 days with correlation coefficient of -0.778. There was strong positive correlation between ASPECTS score at presentation with MoCA at 90 days with correlation coefficient of 0.618. On performing univariate regression, ASPECTS score of less than 6 was a significant risk factor of higher NIHSS at presentation (beta coefficient of 5.273(2.268 to 8.278)) prolonged hospital stay (>7 days odds ratio 27.136(3.522 to 209.097)) poorer mRS score at 90 days (>= 2 with odds ratio of 16.129(1.777 to 146.356)) and greater incidence PSCI at 90 days (MOCA < 26 with odds ratio of 6.855(1.137 to 41.313)). Thus it can be concluded that the at presentation ASPECTS score is a predictor of immediate and long term outcomes in stroke. A study by David et al in 2005 showed an inverse relationship between the at presentation ASPECTS score and the NIHSS score in a linear fashion with a 10 point increase in NIHSS score with every 3 point decrease in ASPECTS score.(8) In a study by Esmael et al, 120 patients with stroke were assessed. The mean ASPECTS score was 7.11+/- 2.43. The mean NIHSS was 13.4+/- 6.9 at presentation. As for long term functional outcomes at three months, patients were divided into groups with mRS less than equal to 2 and more than 2. The average ASPECTS score in both the groups were found to be 8.12 +/- 1.76 and 5.85+/- 2.47 respectively with a p value of 0.001. Thus, patients with lower ASPECTS had poorer functional outcomes at three months. For assessing PSCI, the patients were divided into groups with MOCA cut off of 26 at three months. A strong positive correlation was found between the initial ASPECTS score and MoCA score at 3 months (r=0.69, P=0.003). These findings are similar to observations made in our study [9]. Our study had few limitations. The sample size in our study was small and it may could be the reason why effect of thrombolysis could not be established in our study Though both Hindi and English versions of MoCA were used, educational status of patients might have had an effect on the final interpretation and hence final diagnosis of post stroke cognitive impairment.

Conclusion

The above observational prospective study among 35 stroke patients presenting within 48 hours of stroke onset were studied with an aim to assess the ability of NCCT based ASPECTS score at presentation to determine immediate and 90-day stroke outcomes. The mean age of the subjects was 55.14 years and most were males. Diabetes was the most common risk factor and LVD and SVD emerged as most common stroke etiologies. It was so found that ASPECTS score was correlated negatively with at presentation NIHSS (moderate), length of hospital stay (strong) and 90 day mRS score (strong) and positively to 90 day MoCA score(strong). An ASPECTS score of less than 6 was also a risk factor for greater NIHSS scores, longer hospital stays, greater functional and cognitive disability at 90 days. Also, cardioembolic strokes were found to have greater risk of PSCI at 90 days. ASPECTS score can hence be used as a predictor of immediate and 90-day outcome with respect to both morbidity and cognitive outcomes.

References

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