Between 1991 and 2011, 1198 patients diagnosed with ALS/MND were registered. 929 patients (77.5%) fulfilled the selection criteria and their data were analysed. Median tracheostomy free survival from symptom onset was 28 months in NIV-treated patients compared to 15 months in untreated (Univariate Cox regression HR=0.61 (0.51 to 0.73), p<0.001). The positive survival effect of NIV persisted when the model was adjusted for age, gender, riluzole and percutaneous endoscopic gastrostomy use (HR=0.72 (0.60 to 0.88, p=0.001). In contrast with the only randomised controlled trial, NIV statistically significantly increased survival by 19 months in those with ALS-bulbar onset (Univariate HR=0.50 (0.36 to 0.70), multivariate HR=0.59 (0.41 to 0.83)). These data confirm that NIV improves survival in MND/ALS. The overall magnitude of benefit is 13 months and was largest in those with ALS-bulbar disease. Future research should explore the optimal timing of NIV initiation within phenotypes in order to optimise respiratory function, quality of life and survival.

Performance decrement associated with sleep deprivation is a leading contributor to traffic accidents and fatalities. While current research has focused on eye blink parameters as physiological indicators of driver drowsiness, little is understood of how gaze behaviour alters as a result of sleep deprivation. In particular, the effect of sleep deprivation on gaze entropy has not been previously examined. In this randomised, repeated measures study, 9 (4 male, 5 female) healthy participants completed two driving sessions in a fully instrumented vehicle (1 after a night of sleep deprivation and 1 after normal sleep) on a closed track, during which eye movement activity and lane departure events were recorded. Following sleep deprivation, the rate of fixations reduced while blink rate and duration as well as saccade amplitude increased. In addition, stationary and transition entropy of gaze also increased following sleep deprivation as well as with amount of time driven. An increase in stationary gaze entropy in particular was associated with higher odds of a lane departure event occurrence. These results highlight how fatigue induced by sleep deprivation and time-on-task effects can impair drivers’ visual awareness through disruption of gaze distribution and scanning patterns.

alpha and theta activity), 6 they are diffi cult to measure in fi eld settings due to signal artifact, are not readily amenable to realtime signal processing and are not highly predictive of impaired behavior due to drowsiness. 7 These features have hindered the use of EEG for assessing drowsiness in fi eld settings and the potential to use it to provide real-time drowsiness monitoring.Changes in the frequency, amplitude, and duration of blinks and episodes of slow eye closure occur in response to increased drowsiness caused by sleep deprivation and circadian rhythm effects. [8][9][10][11] While blink duration in rested conditions lasts for less S C I E N T I F I C I N V E S T I G A T I O N SD rowsiness as a result of sleep deprivation, circadian effects, or sleep disorders is a major risk factor for motor vehicle and occupational accidents.1,2 Objective indicators of drowsiness may allow sleepy individuals to be identifi ed in real time in the laboratory, occupational settings, and on the road, with the potential to intervene and prevent accidents. Ideally, indicators of drowsiness for this purpose should be able to detect brief periods of inattention, which may result in an individual failing to respond to hazards in the environment. The lack of validated real-time objective indicators of drowsiness for fi eld research and operational settings, such as driving, restricts both the ability to accurately assess drowsiness in these settings and the development of fi eld-based interventions for drowsiness. Initial laboratory studies have suggested that some ocular measures may be good indicators of drowsiness [3][4][5] ; however, there is a paucity of detailed evaluation of the utility of different ocular measures for this purpose.Electroencephalography (EEG) is the gold standard method for quantifying sleep state (awake versus sleep). Although EEG changes occur with drowsiness in the wake state (increased BRIEF SUMMARYCurrent Knowledge/Study Rationale: Objective indicators of drowsiness have the potential to identify drowsy drivers. This study evaluated the accuracy of ocular measures for detecting drowsiness-related behavioral impairment in real-time. Study Impact: Several ocular measures, particularly those measuring the average duration of episodes of eye closure, were found to be accurate in the real-time detection of behavioral impairment in the laboratory. Ocular measures are promising indicators of real-time drowsiness.