Clinical assessment

Upon admission to the hospital, the National Institutes of Health Stroke Scale (NIHSS) score was recorded for each patient. NIHSS is a well-established and widely used stroke severity assessment score \cite{1995} that includes assessment of orientation, cranial nerve function, motor function, sensation, language, and inattention/visuospatial neglect but not that of other cognitive domains, such as memory or learning \cite{Cumming_2010}. The post-stroke functional outcome was also assessed during two follow-up assessments: (1) within 2-5 days after admission (average 2.6 days, "early" in-hospital follow-up) and (2) at 90 days ("late" follow-up). The 90-day NIHSS score was only available for 28 of the patients, while NIHSS score distribution for both assessments is illustrated in Figs.\ref{860740}-\ref{947150}. Additionally, the modified Rankin Scale (mRS) score \cite{Rankin_1957} was recorded at "late" follow-up to assess functional status of the SALVO patients \cite{Bloch_1988}. mRS ranges from 0 (no symptoms at all) to 6 (dead) and offers no detailed differentiation of neurological domains affected by stroke. It focuses on the assessment of functional independence (ability to return to independent living, including ambulation without assistance), and is widely used in stroke clinical trials based on its high utility and reliability \cite{Wilson_2005,Banks_2007,Quinn_2009}.