Reliability and Validity of the Canadian Neurological Scale, Thai Version
Lantharita Charoenpong MD*, Pipat Chiewvit MD**, Julajak Limsriwilai MD*, Songkram Chotikanuchit MD*, Napaporn Yamkaew BSc*, Niramol Lirathpong BSc*, Chulaluk Komoltri PhD***, Niphon Poungvarin MD, FRCP, FRI*, Yongchai Nilanont MD*
Affiliation : * Department of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand ** Department of Radiology, Siriraj Hospital, Mahidol University, Bangkok, Thailand *** Department of Research development, Mahidol University, Bangkok, Thailand
Background : The Canadian Neurological Scale (CNS) is one of the most reliable stroke severity assessment scales. There is
a strong need for a simple and well validated stroke severity assessment scale among Thais.
Objective : To translate and perform a reliability and validity study of the Canadian Neurological Scale, Thai version (CNS-
T).
Material and Method: Forward and backward translations of the original CNS version were independently performed. The
final version of the CNS-T was prospectively tested for reliability and validity in acute ischemic stroke setting. Consecutive
series of acute stroke patients were assessed by one of the six raters from three different types of healthcare providers: 2
stroke nurses, 2 internal medicine residents and 2 stroke fellows. Each patient was independently assessed twice at 3 weeks
interval using video tape by all raters. Extent of infarction was measured by MRI lesion volume. Clinical outcome at 3 months
was measured using modified Rankin Score (mRS). Correlation among the CNS-T and 3-mo mRS and MRI lesion volume
were assessed. Inter and intra-observer reliabilities were evaluated.
Results : A total of 38 patients were enrolled. Median CNS-T was 8.5. Intra-observer reliability demonstrated a high
agreement with an intraclass correlation (ICC) of 0.99, 0.97, 0.98, 0.96, 0.93 and 0.98 for 2 stroke fellows, 2 internal
medicine residents and 2 stroke nurses respectively. Inter-observer reliability between the 6 raters was excellent: ICC 0.87
(95% CI; 0.81-0.92). The Spearman rank correlation coefficient was -0.55 (p = 0.001) between the initial CNS-T score
versus initial MRI lesion volume and -0.61 (p < 0.001) between the initial CNS-T score versus 3-mo mRS.
Conclusion : The CNS-T can be performed by trained nurses, internists and neurologists with an excellent reliability. The
CNS-T is a valid and simple clinical tool for stroke severity assessment among Thais.
Keywords : Acute stroke, Canadian Neurological Scale (CNS), Stroke
