SLEEP 2011 Abstract Supplement

A. Basic Science XII. Instrumentation and Methodology
0313
VALIDATION OF A MODIFIED BRIEF VERSION OF THE
PSYCHOMOTOR VIGILANCE TEST (PVT)
Basner M 1 , Mollicone DJ 2 , Dinges DF 1
1
Department of Psychiatry, University of Pennsylvania School
of Medicine, Philadelphia, PA, USA, 2 Pulsar Informatics, Inc.,
Philadelphia, PA, USA
Introduction: The Psychomotor Vigilance Test (PVT) objectively assesses
fatigue-related changes in behavioral alertness associated with
sleep loss, extended wakefulness, circadian misalignment, and time on
task. However, the standard 10 min PVT is often considered impractical
in applied contexts. To address this limitation, we developed a modified
briefer (3 min) version of the PVT (PVT-B).
Methods: The PVT-B was validated in controlled laboratory studies
with 74 healthy subjects (34 female, aged 22-45 y) that participated
either in a total sleep deprivation (TSD) study involving 34 h awake
(N=31) or in a chronic partial sleep deprivation (PSD) protocol involving
5 nights of 4 h time in bed (N=43). PVT and PVT-B were performed
regularly during wakefulness. Mixed model ANOVAs were used to test
the sensitivity of PVT-B and PVT to TSD and PSD, on each of 5 key
PVT outcomes.
Results: Effect sizes were largest for sensitivity of response speed to
both forms of sleep loss for both the PVT-B and the PVT. Effect sizes
were also larger for TSD than PSD, and larger for PVT than for PVT-
B for all outcomes. Effect sizes for the PVT-B were still substantial,
and compared to the 70% decrease in test duration, the 23% average
decrease (range 7%-69%) in effect size was acceptable. After reducing
the lapse threshold from 500 ms to 355 ms for the 3 min PVT, there
was no indication of differential sensitivity to sleep loss between PVT-B
and PVT for the primary PVT outcome variables of lapses and response
speed (P>0.15).
Conclusion: PVT-B tracked standard 10 min PVT performance throughout
both TSD and PSD, and yielded high effect sizes. PVT-B is a useful
tool for assessing behavioral alertness in settings where the duration of
the 10 min PVT is considered impractical, although further validation in
applied settings is needed.
Support (If Any): This investigation was sponsored by the National
Space Biomedical Research Institute through NASA NCC 9-58, and
in part by NIH grants M01-RR00040, NR04281 and CTRC UL1
RR0241340, and by the Department of Homeland Security’s Transportation
Security Laboratory Human Factors Program (FAA #04-G-010).
0314
AN EVALUATION OF SPLIT AND MANUAL TITRATION
STUDIES IN SQUH SLEEP LABORATORY ACCORDING TO
AASM CRITERIA
AL-Habsi MM
Clinical Physiology Department, Sultan Qaboos University Hospital,
Al-Mudhaibi, Oman
Introduction: PAP devices are used to treat patient with sleep related
breathing disorders and their sittings are obtained by full night or spilt
night titration studies. This study was conducted in Sultan Qaboos University
Hospital as a part of auditing the service in the sleep laboratory
according to AASM grading system of PAP titration which include four
different grades describe the result of titration (optimal, good, adequate
and unacceptable) which concentrate in reduction of RDI and the presences
of supine REM sleep.
Methods: Split night and manual titration studies from 2008, 2009 and
2010 (excluding December of 2010) were reviewed. The data were collected
retrospectively from Polysomnography reports and hospital medical
records.
Results: From 654 PSG studies where reviewed only 96 (15%) were
split and manual titration studies. The percentage of split and manual titration
studies increased year by year (9%:2008, 22%:2009, 21%:2010).
Among those titration studies in 2008 29% optimal, 12% good, 24% adequate
and 35% unacceptable. While in 2009 47% optimal, 24% good,
8% adequate and 21% unacceptable and the case in 2010 were 49%
optimal, 12% good titration, 19.5% adequate and 19.5% unacceptable.
From this statistics the reasons for this are lack of trained technologists
to perform the titration correctly and the lack of a titration protocol
which only seen after 2008. The second reasons for this failure was due
conditions directly related to patients such as central sleep apnea, Chain-
Stokes breathing and emergence of complex sleep apnea.
Conclusion: The primary reason related to technologist in which they
are not providing patient with enough education about the device (acclimatization),
so patients will not easily accept the device. In order to
overcome this, more training is required and follow up and checking
technologist titration randomly and continuously to make sure they are
using the proper way of titration.
0315
UNSUPERVISED PARADOXICAL SLEEP DEPRIVATION
USING POLYGRAPHIC SIGNALS IN RATS: A NEW
ALTERNATIVE TO THE “FLOWER POT” TECHNIQUE
Libourel P, Corneyllie A, Chouvet G, Luppi P, Gervasoni D
CNRS UMR5167, Lyon Cedex 08, France
Introduction: Selective paradoxical sleep (PS) deprivations (PSD) can
be efficiently performed by using the classical “inverted flower pot”
method. Once installed on one or several platforms surrounded by water
animals refrain from entering PS, and present a PS hypersomnia (rebound)
when placed back in their home cage. In the first hours of deprivation
this method also suppresses SWS; hence it cannot be used for
short selective PSD. As a non-stressful alternative, manual deprivations
are possible but involve an operator who constantly scrutinizes the sleep
recordings and manually wake-up the animal. Here we introduce an approach
based on a real-time detection of PS coupled to a new mechanical
device to awaken the animal.
Methods: Our adaptative algorithm identifies PS from EEG and EMG
signals. When PS is detected, a stimulus is applied with a device placed
underneath the cage that produces a sudden descent of the cage’s floor
followed by a slow return to its initial level. This new method was used
in two paradigms, a 6-hour PSD, and a 72-h PSD.
Results: When applied to baseline recordings, our algorithm gave a
high concordance with human scoring (>95%). Notably, the specificity
to detect PS reached 98%. A first group of rats went through a 6-h
manual PSD. Manual PSD was followed by an increase in PS amounts:
29.2±2.9% vs 12.6±2.6% in baseline (n=3, over 2h). With the unsupervised
PSD, PS rebounds had a slightly less magnitude 22.1±7.6% vs
14.0±3.3%. Another group of animals went through a 72h PSD using
the platform technique and, two weeks later, through a second 72h-PSD
with our new device. The rats were then euthanized 180 minutes after
the end of PSD, and brain sections were collected for Fos-labeling. On
average, PS amount during the rebound was smaller after the unsupervised
PSD (23.3±3.3% vs 41.2±5.1% over 3h; n=6), while SWS amount
did not significantly differ (46.6±10.8 vs 43.7±4.5%). The smaller rebound
with the unsupervised PSD might primarily result from a lower
stress level and to a less extent from residual PS bouts. Analysis of Fos
labeling (n=3) revealed similar activation levels after PS hypersomnia,
as those described after the classical PSD.
Conclusion: Altogether our results show that our approach can efficiently
overcome the limitations of manual detection when performing
short PSD, and constitutes a valuable alternative to the classical technique
for long PSD.
SLEEP, Volume 34, Abstract Supplement, 2011
A110