Detailed Analysis of Sleep Study Report in Clinical Trial

This report analyzes a sleep study conducted as part of a clinical trial for a new sleep medication. It begins by identifying and explaining five demographic and lifestyle factors that can negatively impact sleep, such as lighting, sleep environment, working hours, medication, anxiety/stress, and body pain. The report then examines a provided overnight polysomnogram (PSG) report of a participant with normal sleep, highlighting three key pieces of information that support this conclusion, including sleep efficiency, total sleep time and wake after sleep onset. The report also includes a hypnogram, defining each sleep stage (wake, REM, light, and deep) by color and description, and describes the participant's REM sleep pattern. Finally, the report marks the minimum recommended EEG derivations on a figure. The assignment comprehensively covers the evaluation of sleep data and the factors influencing sleep quality within a healthcare research context.

WRITTEN ASSESSMENT
You are a qualified sleep technician in a large hospital. Your sleep laboratory has
been chosen to be part of a world-wide clinical trial for a new sleep medication. For
the first stage of this trial, laboratories need to recruit young healthy males with
normal sleep (timing and duration) to participate. There are rigorous screening
procedures that include a serious of general health and sleep questionnaires. If all
written criteria are met, then potential participants are invited into the sleep
laboratory for an overnight for a ‘typical’ night (timing and duration).
A potential participant has met all the written criteria and attended the sleep
laboratory last night for their overnight polysomnogram. Their sleep has been scored
by a fellow technician and the report and recording is available for review. Using this
background information, the report and samples from their overnight polysomnogram
below, please answer the following questions.

1) There are a number of demographic, and lifestyle factors that can negatively
impact sleep. Identify any five of these factors that may have been queried in the
initial questionnaire screening and explain how they can affect sleep in the table
below. (15 marks)
Factor affecting sleep How factor negatively affects sleep
Lighting Light is considered as one among the most influential
factor that affects the individuals sleep. It directly
creates difficulty for the individual to fall asleep as
their retina is sensitive which gets affected by light.
This directly awakens those cells which are present
in the retina. The main function of these cells is to
make external vision clear to the individual. It also
informs brain about the actual time that whether it is
a day time or it is night time. It can be said that if
excessive amount of light is available in the room
then it will directly influences sleep of people as cells
present in retina makes them unconscious which
does not allow them to sleep properly. Along with
this, it can also be said that exposure of lighting in
sleeping room influences internal clock and results in
interruption of sleep or could also delay it negatively.
Sleep environment Environment of bedroom belongs to external factor
that plays a significant role on the sleep of individual.
This factor is developed with the collaboration of
various environment such as noise, light,
temperature, proper availability of oxygen supply etc.
it can be said that absence of any of these variable
could influence individual as they are not able to take
appropriate quality of sleep due to their unavailability.
It has been analysed that if bright light is available in
individual room then it could affect internal clock of
the people which could delay their sleep timing.
Along with this, it has also been analysed that if
appropriate level of oxygen is not present in the room
then it would be feasible for participants to take good
and healthy sleep as they are not able to breath in
the room which makes them unconscious which
leads to delay in the sleep.
Working hours or shift Shift in work or time zone is seen as the another
influential factor which affects sleep of the participant.
It has been identified that individual who works in
rotational working hour or their job is related to
travelling faces problems associated to sleep. This is

because, change in working hour disturbs their
internal clock which directly affects their sleeping
pattern. It has been seen that when working hours of
individual changes then their internal clock working
schedule works in opposite direction. This means,
when individuals gets free to take rest or sleep at that
time their internal clock does not allow them to sleep.
And when the internal clock directs them to sleep
then their official working hours makes it unable for
them to take rest or sleep. This shows the negative
influence of shift or working hour factor over the
individuals sleep.
Medication Individuals are taking numerous of medicines,
caffeine and nicotine which ultimately influences their
quality of sleep. It has been analysed that there are
numerous of doctors which gives heavy dose
sleeping tablets to patients so that they can take a
healthy course of sleep as without these tablets it
would not be possible for these patients to sleep. But,
while evaluating this situation in depth, it has been
identified that there regular intake of these chemicals
makes individual addicted of it. As a result, it directly
becomes impossible for them to get healthy sleep
without consuming chemical based medicines of
sleep. This depicts negative influence of medication
factor over the sleep of individual.
Anxiety or stress Stress and anxiety is considered as an high
influential factor which places impact over the sleep
of participants. It has been analysed that when an
individual is in stress mode then they are even not
able to respond in the day time the thing works
similar at the night time too. This means, whenever
stress or anxiety level of individual is high then it
becomes difficult for them to sleep at night too as
they are not feeling good internally which makes
them feel unconscious. In maximum cases,
participants who are suffering from anxiety or stress
goes through Rapid eye movement sleep instead of
deep sleep.
Body Pain or ache Pain or ache creates numerous of difficult for
individuals as they are not in a state which keeps
them calm or allows them to take rest. It has been
identified that whenever any individual suffers from
joint pain or severe headache then they are not able
to get a healthy sleep because they awakens many
times at night. This happens due to discomfort level
of a person which leads to make them away from
taking a good and long lasting sleep which could
relax them as well as their mindset. It can be said
that pain works as the negative factor individual that

not only makes it difficult to deal with it in a day time
but it also affects their sleep as well.
2) An Overnight PSG Report of a participant in a sleep study is provided above. The
participant was noted to have normal sleep. Identify 3 key points of information in the
report which support the conclusion that the participant’s sleep is normal. Justify your
answer. (6 marks)-
1) Sleep Efficiency & Latency
Since REM Latency rate lies between 60 to 120 minutes i.e. 68.0 min., so it
indicates that participant's sleep is 95.9% efficient and normal sleep. The given
patient also has relatively normal sleep stages, efficiency and latency for the sleep
lab. This would also shows the normal sleep of him with no symptoms of sleeping
disorders.
2) Total Sleep Time (TST)
As at normal sleep, stages lie as
Normal 5% N1, 50% N2, 20% SWS/N3 and 20-25% REM
Normal sleep efficiency >80-85%
Sleep onset latency < 30 min, REM latency < 120 min
In OSA & other sleep disorders, increased N1 (light sleep), decreased REM (OSA
more severe)
here, in present report. At stage 2, percentage of NST measures as 53.3% which
is above from average and non-rapid eye movement at stage N3 counted as
83.7%. This factor also shows normal efficiency of sleep of given participant. In

addition to this,that shows same is total sleep time taken by this individual out of
480.0 min., is 460.5.
3) Wake after sleep onset (WASO; TRT-SL-TRT)
If WASO < 1 to 20% of TBT, sleep latency lies between 20 to 30 min and REM
latency is also 60 to 120% then, under such conditions, patient's sleep is
considered as 80 to 85% efficient. In present context, WASO of given participant
measures as 15.5% therefore, his sleep efficiency is taken as normal.
3) Below is the hypnogram from their recording, showing distribution of sleep stages
over time.
a) Identify the colour associated with each sleep stage and give a brief description of
each sleep stage in the table below. (4 marks)
Sleep stage Colour on hypnogram Description
Wake Red This is the lightest stage of NREM that also
known as drowsy sleep stage and can easily
be disrupted by awakenings and arousals.
Here, eyes are open, responsive towards
external stimuli, can do intelligible
conversation.
REM Yellow REM sleep also known as rapid eye
movement stage which can be
considered as the dreaming stage as
well. Here, eye movements are
measured as rapid i.e. moving from side
to side. Along with this, brain waves
also considered as more active.
Light Green It occurs as longer than stage 1 that
compromises near about 40 to 60% of TST
i.e. total sleep time. Here, awakenings or
any kind of arousals mostly not occur like
stage 1 and slow movement of eye rolls
also discontinue. It is a main body of light
sleep where brain waves and heart rate
continue to slow.
Deep Cyan Here, the deep sleep occurs in stage 3 of
NREM stage, therefore, it is considered as
better restorative stage and sleep stage
seems to be less affected by external
factors. Therefore, it seems to be difficult

to awaken a person at this stage of deep
sleep.
b) Describe the pattern of REM sleep across the night, is this normal? (2 marks)
Through given report, where, jump has been seem around deep, light and REM
frequently, here, it has analysed that healthy amounts of these stages reduces
wake times. The pattern of minimal deep sleep doesn't show here with an
overbundance of light sleep.

4) Below is a screenshot of the recording taken during the polysomnographic study
conducted on the participant. On the left-hand side are the minimum recommended
EEG derivations as outlined by the AASM. Mark these sites on the figure below.
(4 marks)-- 180

Here, FP1, FP2 are prefrontal T3 and T4 are mid-temporal
F3 and F4 are frontal T5 ad T6 are posterior temporal
C3 and C4 are central A1 and A2 are mastoid
P3 and P4 are parietal FZ is frontal midline
O1 and O2 are occipital CZ is central vertex
F7 and F8 are anterior temporal PZ is parietal midline
N is Nasion and I is Inion

5) The screenshot below is taken from the bio-calibration part of the recording. The
technician has marked on the recording that the participant has been asked to close
their eyes for 30 seconds.
a) If the participant is still awake, why does the EEG look so different compared to
eyes open? (1 mark)
At this stage, the body of a person start to go into relaxation position, but as theta
waves are dominated still the brain activities, therefore, they can be easily
interrupted via brief burst activities like sleep spindles.
b) There are three EEG derivations shown, why do they look slightly different from
one another? (1 mark)
When a person start to go to sleep then body start to go into deep relaxation.
Therefore, with passage of time, pattern of brain activities i.e. EEG derivations start
changes also. They seem to be lesser interrupted in response towards external
stimuli. Therefore, at different-different stages of sleeping, brain activities seems to
be changes and therefore, EEG derivations quite looking different from each other.
c) What is frequency of the predominant EEG rhythm shown? (1 mark)
As stage 1 of sleep stages is associated with both theta and alpha waves in
terms of brain activity, therefore, at this phase, there is a relatively low frequency
measures as 8 to 13 Hz. At predominant stage, pattern of brain activity compares
with others who are very relaxed, seem to be awake.

6) The following 30 sec epoch has been scored as REM. Identify two factors that
support this? Justify your answers. (6 marks)
Factor 1: Sleep spindle Justification: Sleep Spindle refers to the quick
burst of brain waves at high frequency which
seems to look much important for the memory
as well as learning. It generally occurs at
second stage of light sleep. This depicts that
various fluctuation takes place at participant
brain while they were in the light sleep mode of
stage two. According to the above specified
epoch of patient, it has been analysed that
sleep spindles are of 15 seconds which states
that the mental processing of the participant
was normal at that time. At this specific time,
individual can continues their sleep cycle and
can also easily move to the another that is next
stage of sleep which means that deep sleep.
Factor 2: K - complex Justification: K- complex is considered as the
structure or pattern of brain activity which
occurs due to environmental stimuli. This factor
is quite different from sleep spindles as it
depicts that large waves takes place as per the
reaction of external stimuli at the time of
sleeping. The main symptom of this K
complexes is that it occurs before the
movement of legs. This leads to restless sleep
as participant is not able to take proper sleep

due to higher fluctuation in brain waves.

7) What would the epoch below be scored as? Justify your answer. (5 marks)
The score of given 30-sec epoch consists of below information:
 Onset of sleep after the lights were turned off is less than 20 min. Under this
condition, patient feel like they are awake but report of EEG shows that they
are sleeping due to individual differences in both theta and alpha waves in
brain activities.
 Sleep efficiency which is measured by dividing the number of minutes sleep
by total number of sleep duration, if measured as 85 to 90%, then under
such condition, person's sleep consider as normal.
With this assistance, each 30 sec epoch from given graph is scored as 'awake' or
one of the four stages of sleep.