The PSG

narcolepticnerd August 28, 2011 0 comments

My PSG Experience: August 28th, 2011

On the night of August 28th, 2011, I was instructed to arrive at the sleep clinic late in the evening, around 10 pm. After checking in, the technician began the process of attaching approximately 50 leads to my body—several on my head to monitor brain activity, others on my chest to track heart rate and breathing, and more on my legs to detect movement. This setup was for the polysomnogram (PSG), the overnight test designed to observe how well I sleep and to look for any abnormalities.

Once I was fully wired up and settled into bed, the technician told me to try to get some sleep. Despite the unusual feeling of being connected to so many sensors, I managed to relax. According to the person monitoring me throughout the night, the leads detached from my body multiple times and had to be reattached, but overall, I was able to get a very good night’s sleep. The PSG provided valuable data that would help guide my diagnosis and treatment moving forward.

The Results

PSG Results (Page 1)

The following results are from page 1 of my Diagnostic Polysomnography Report, dated August 28, 2011:

  • Apnea and Hypopnea Index (AHI): 2.4 events per hour of sleep
  • Apnea, Hypopnea, and RERA (RDI): 8.3 events per hour of sleep
  • RDI while sleeping on back: 11.5 events per hour
  • Oxygen saturation dropped as low as 86%, with 1.0 minute spent below 90%
  • Limb movements: 0.0/hr (no significant limb movement or arousals)

These results indicate mild respiratory disturbances and some oxygen desaturation, but no significant limb movement issues. This is page 1 of the full sleep study report.

PSG Results (page

Page 2 of my Diagnostic Polysomnography Report provides additional details about the procedure and my sleep staging data from the night of August 28, 2011:

Procedure: Polysomnography was conducted overnight, recording left and right EOG, submental EMG, left and right anterior tibialis EMG, frontal, central, and occipital EEG, continuous EKG waveform, airflow, respiratory effort, oximetry, and video. Hypopneas were scored according to AASM standards.

Sleep Staging Data:

  • Lights out: 9:47:03 PM
  • Sleep onset: 9:57:23 PM
  • Lights on: 6:24:05 AM
  • Sleep efficiency: 93.2%
  • Time in bed: 519 min
  • Total sleep time: 493.5 min
  • REM onset: 111.0 min after sleep onset
  • Wake during sleep: 19.1 min
  • Total wake time: 35.5 min

  • of REM periods: 4


Sleep Stages (% of total sleep time):

  • Stage N1: 7% (36 min)
  • Stage N2: 52% (259 min)
  • Stage N3: 20% (99 min)
  • REM: 21% (99 min)

PSG Results (Page 3)

Page 3 of my Diagnostic Polysomnography Report provides a detailed summary of respiratory events, body position data, heart rate, and limb movement during my sleep study:

Respiratory Events Summary (Total Sleep Time):

  • Central Apneas (CA): 1 event
  • Obstructive Apneas (OA): 3 events
  • Mixed Apneas (MA): 0 events
  • Hypopneas (HYP): 16 events
  • RERA (Respiratory Effort Related Arousals): 48 events
  • Apneas + Hypopneas: 20 events
  • Mean duration of apneas: 10.5–13.3 seconds
  • Index (events/hour): Apneas + Hypopneas: 2.4/hr, RERA: 5.8/hr

Respiratory Event Index by Sleep Stage:

  • AHI (Apnea-Hypopnea Index): REM: 3.1/hr, NREM: 2.2/hr, Total: 2.4/hr
  • RDI (Respiratory Disturbance Index): REM: 8.5/hr, NREM: 8.2/hr, Total: 8.3/hr

Body Position Data:

  • Supine (on back): 352.5 min, RDI: 11.5/hr
  • Left side: 127.1 min, RDI: 1.0/hr
  • Right side: 45.1 min, RDI: 4.1/hr

Heart Rate Data:

  • Mean heart rate (BPM): Wake: 80.9, REM: 71.3, NREM: 67.5

Periodic Limb Movement Data:

  • Total number of limb periods: 0
  • PLM Index: 0.0/hr
  • PLM Arousal Index: 0.0

These results further confirm mild sleep-disordered breathing, with most events occurring while sleeping on my back, and no significant limb movement issues. This is page 3 of my full sleep study report.

PSG Results (Page 4)

Page 4 of my Diagnostic Polysomnography Report focuses on arousals, oximetry, and oxygen desaturation during my sleep study:

Arousals:

  • Total arousals: 124
  • Respiratory arousals: 53
  • PLM (Periodic Limb Movement) arousals: 0
  • Spontaneous arousals: 71
  • Arousal index: 15.1/hr (respiratory: 6.4/hr, spontaneous: 8.6/hr)

Oximetry Data:

  • Average O2 while awake: 96%
  • Average O2 while in REM: 94%
  • Average O2 while in Non-REM: 94%
  • Lowest O2 value: 86%

Oximetry Distribution:

  • Time spent below 95% O2: 38.2 min (mostly in NREM)
  • Time spent below 90% O2: 0 min
  • Desaturation index: 4.5/hr
  • Desaturation max duration: 58.5 sec
  • Desaturation max %: 8%

These results show that while there were a number of arousals and some mild oxygen desaturation, there were no significant limb movement arousals and no prolonged periods of severe hypoxemia. This is page 4 of my full sleep study report.

These results show good sleep efficiency, normal distribution of sleep stages, and four REM periods. The data from both pages of the PSG report were used to help guide my diagnosis and treatment plan.

So What is a PSG?

A Polysomnogram (PSG) is an overnight sleep study used to diagnose sleep disorders. It records brain waves, oxygen levels, heart rate, breathing, and eye and leg movements. The PSG is typically performed in a sleep lab and provides a comprehensive picture of how a person sleeps, helping to identify issues such as sleep apnea, restless legs syndrome, and narcolepsy. August 29th 2011 I will be doing whats called a MSLT

What is an MSLT?

The Multiple Sleep Latency Test (MSLT) is a daytime sleep study that usually follows a PSG. It measures how quickly a person falls asleep in a quiet environment during the day and how quickly they enter REM sleep. The MSLT consists of a series of five scheduled naps, each separated by two hours. It is the gold standard for diagnosing narcolepsy and excessive daytime sleepiness.

How They Work Together

A PSG is often performed first to rule out other sleep disorders and to ensure that the patient had adequate sleep before the MSLT. The MSLT then provides objective data on sleepiness and REM onset, which are critical for diagnosing narcolepsy and other hypersomnia disorders.

Why Are They Important?

Together, the PSG and MSLT provide a thorough assessment of sleep health. They are essential tools for sleep specialists to accurately diagnose and treat complex sleep disorders, ensuring patients receive the right care and support.

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