Amyotrophic lateral sclerosis & frontotemporal degeneration
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Amyotroph Lateral Scler Frontotemporal Degener · Nov 2019
ALS/SURV: a modification of the CAFS statistic.
We present a composite endpoint that can be used in amyotrophic lateral sclerosis (ALS) trials, which combines functional status (via the ALS functional rating scale) and survival, denoted ALS/SURV. ALS/SURV modifies and extends the combined assessment of function and survival (CAFS) score and assigns rankings to participants that withdraw or are lost to follow up in a way that does not disproportionately lower and skew ranks for those participants that reach study endpoint (either death or study completion). ALS/SURV has properties of: (1) ordering participants that completed the study from the shortest surviving participant to the last observed death followed by worst function to best function; (2) ordering participants withdrawing at time of withdrawal by their decline in functional status relative to all the participants still in the study; and (3) then maintaining this ordering at time of withdrawal relative to participants still in the study. ⋯ Additionally, ALS/SURV can be summarized as either median functional status or median survival along with interquartile range, thereby adding clinical meaning to the statistic. Finally, by applying normal deviates, confidence intervals can be computed and used to estimate power for future studies. In summary, the above properties support the role for ALS/SURV as a new ALS composite statistic.
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Amyotroph Lateral Scler Frontotemporal Degener · Nov 2019
Longitudinal analysis of sniff nasal inspiratory pressure assessed using occluded and un-occluded measurement techniques in amyotrophic lateral sclerosis and primary lateral sclerosis.
Objective: Sniff nasal inspiratory pressure (SNIP) is a commonly used clinical measure of respiratory impairment in amyotrophic lateral sclerosis (ALS), which is used to guide the initiation of noninvasive ventilation (NIV). SNIP can be completed with either an occluded or an un-occluded contralateral nostril. The aim of this study was to compare occluded and un-occluded SNIP measurements and to examine the decline in occluded SNIP over time compared to the ALSFRS-R respiratory subscore. ⋯ This showed a linear decline in spinal onset with a floor effect in bulbar-onset ALS. Conclusion: SNIP measured with an occluded and un-occluded contralateral nostril is not interchangeable, which is relevant in interpreting thresholds for initiation of NIV. SNIP declines non-linearly, which is explained in spinal onset ALS by age and diagnostic delay, but an apparent floor effect remains in bulbar onset.