Posterior National Institutes of Health Stroke Scale Improves Prognostic Accuracy in Posterior Circulation Stroke

Abstract

Background and Purpose: The National Institutes of Health Stroke Scale (NIHSS) underestimates clinical severity in posterior circulation stroke and patients presenting with low NIHSS may be considered ineligible for reperfusion therapies. This study aimed to develop a modified version of the NIHSS, the Posterior NIHSS (POST-NIHSS), to improve NIHSS prognostic accuracy for posterior circulation stroke patients with mild-moderate symptoms. Methods: Clinical data of consecutive posterior circulation stroke patients with mild-moderate symptoms (NIHSS <10), who were conservatively managed, were retrospectively analyzed from the Basilar Artery Treatment and Management registry. Clinical features were assessed within 24 hours of symptom onset; dysphagia was assessed by a speech therapist within 48 hours of symptom onset. Random forest classification algorithm and constrained optimization were used to develop the POST-NIHSS in the derivation cohort. The POST-NIHSS was then validated in a prospective cohort. Poor outcome was defined as modified Rankin Scale score ≥3 at 3 months. Results: We included 202 patients (mean [SD] age 63 [14] years, median NIHSS 3 [interquartile range, 1–5]) in the derivation cohort and 65 patients (mean [SD] age 63 [16] years, median NIHSS 2 [interquartile range, 1–4]) in the validation cohort. In the derivation cohort, age, NIHSS, abnormal cough, dysphagia and gait/truncal ataxia were ranked as the most important predictors of functional outcome. POST-NIHSS was calculated by adding 5 points for abnormal cough, 4 points for dysphagia, and 3 points for gait/truncal ataxia to the baseline NIHSS. In receiver operating characteristic analysis adjusted for age, POST-NIHSS area under receiver operating characteristic curve was 0.80 (95% CI, 0.73–0.87) versus NIHSS area under receiver operating characteristic curve, 0.73 (95% CI, 0.64–0.83), P =0.03. In the validation cohort, POST-NIHSS area under receiver operating characteristic curve was 0.82 (95% CI, 0.69–0.94) versus NIHSS area under receiver operating characteristic curve 0.73 (95% CI, 0.58–0.87), P =0.04. Conclusions: POST-NIHSS showed higher prognostic accuracy than NIHSS and may be useful to identify posterior circulation stroke patients with NIHSS <10 at higher risk of poor outcome.

Outcomes of Endovascular Therapy in Young Patients with Acute Basilar Artery Occlusion: A Substudy of BASILAR Registry Study

“…Our findings also reveal associations between admission NIHSS, pc-ASPECTS, and recanalization and favorable outcomes at 90 days, which is further supported by previous studies [ 30 , 31 ]. Interestingly, we found sex as an independent predictor of mortality within 90 days for young patients.…”

Endovascular versus Medical Management of Acute Basilar Artery Occlusion: A Systematic Review and Meta-Analysis of the Randomized Controlled Trials

“…Management of patients with mild symptoms is challenging as some may improve without EVT while others may deteriorate. The NIHSS also has reduced sensitivity to detect potentially disabling deficits in patients with posterior circulation stroke [ 35 ]. Prior studies showed divergent results of EVT in these patients as it carries increased procedural risks, especially in patients with underlying intracranial atherosclerotic disease (ICAD) [ 12 , 36 , 37 ].…”

“…The NIHSS also has reduced sensitivity to detect potentially disabling deficits in patients with posterior circulation stroke. 35 Prior studies showed divergent results of EVT in these patients as it carries increased procedural risks, especially in patients with underlying intracranial atherosclerotic disease (ICAD). 12,36,37 Randomized trials comparing EVT versus MM in BAO patients with mild strokes are warranted.…”

Prevalence of stroke in acute vertigo presentations: A UK tertiary stroke centre perspective

“…A median NIHSS score of one, and average of 2, in imaging confirmed stroke patients in our cohort suggests that further work is needed to develop scoring systems appropriately weighted for posterior circulation strokes. Perhaps the addition of gait and truncal ataxia would improve the prognostic accuracy and hence the therapeutic value of NIHSS scores in patients with posterior circulation strokes with mild to moderate symptoms [22].…”