| PALATE | The soft tissue flap that hangs down the back of the throat attached to the roof of the mouth. The tip is also called the uvula. The whole structure is often called the soft palate to differentiate it from the roof of the mouth (a bony structure) also called the hard palate. |
| PANIC AROUSALS | Episodes of aweking with sensation of panic. Sometimes due to bad dreams and stress or as a consequence of waking and sensing the upper airway is blocked. |
| PAP | Positive Airway Pressure. This is the most common and effective treatment for obstructive sleep apnea (OSA). It provides a stream of air through a mask that you wear during sleep. This airflow keeps the airway open preventing pauses in breathing and restoring normal blood oxygen saturation. PAP can be continuous (CPAP) bilevel (BPAP) or autotitrating (APAP). |
| Parasomnia | An event happening during sleep or induced or exacerbated by sleep such as sleepwalking or asthma; not a dyssomnia. |
| Paroxysmal nocturnal dyspnea (PND) | Respiratory distress and shortness of breath due to pulmonary edema appearing suddenly and often awakening the sleeping individual. |
| Pathological Sleep | Abnormal sleep patterns. |
| Pavor Nocturnus (Night Terrors) | See Night Terrors. |
| PCP | Primary Care Physician |
| Perceptual Disengagement | Change in consciousness at the onset of sleep when environmental stimuli are no longer perceived and there is no longer any conscious meaningful interaction with the environment. |
| Periodic Breathing | Repetitive apneic pauses common in premature infants. |
| Periodic Limb Movement Disorder | Also known as periodic leg movements and nocturnal myoclonus. Characterized by periodic episodes of repetitive and highly stereotyped limb movements occuring during sleep. The movements are often associated with a partial arousal or awakening; however the patient is usually unaware of the limb movements or frequent sleep disruption. Between the episodes the legs are still. There can be marked night-to-night variability in the number of movements or in the existence of movements. |
| PERIODIC MOVEMENTS OF THE LEGS DURING SLEEP (PMLS) | Also known as nocturnal myoclonus. A condition where the legs move every 40 seconds or so producing brief arousals. Commonly seen in the first few weeks on nasal CPAP (not understood why). Another cause of daytime sleepiness. |
| Persistent Insomnia | Continuing insomnia responding poorly to treatment. |
| PET | Positron Emission Tomography |
| Pharynx | Area posterior to the nares and the oral cavity; passageway for air from the nasal cavity and/or the mouth to the lungs via the larynx and the trachea for food and liquids from the mouth to the esophagus |
| PHARYNX (fa-rinx) | Essentially the throat area between the voice box and the back of the nose behind the tongue. A floppy muscular tube. |
| Phase advance | Movement to a position earlier in the 24 hour sleep - wake cycle of a period of sleep or wake; for example a shift of the sleep phase from 11 p.m. - 7 a.m. to 8 p.m. - 4 a.m. |
| Phase delay | Phase delay is exactly the opposite of phase advance i.e. a shift later in time. |
| Phasic (Event/Activity) | Brain muscle or autonomic related event of a brief and episodic nature occurring in sleep. Usually occur during REM sleep such as eye movements and/or muscle twitches. |
| Photoperiod | Duration of light in a light/dark cycle. |
| Pickwickian Syndrome | Obesity accompanied by somnolence lethargy chronic hypoventilation hypoxia and secondary polycythemia (a condition marked by an abnormal increase in the number of circulating red blood cells); usually has severe obstructive sleep apnea. |
| PICKWICKIAN SYNDROME | An old term for large people with problems of underbreathing. Included a lot of diagnosis. No longer used by those that know! |
| Pineal Gland | Gland in the brain secreting the hormone melatonin. |
| PLMD | Periodic Leg Movement Disorder |
| PLMD-Arousal Index | Number of sleep-related periodic leg movements per hour of sleep that are associated with an EEG arousal. |
| PLMS | Periodic Leg Movements of Sleep |
| PND | Paroxsymal Nocturnal Dyspnea |
| PO2 | Partial pressure of oxygen (O2) in the blood. |
| PO2 | Partial pressure of oxygen (O2) in the blood. A value above 60 is usually considered a safe level: lower than 60 indicated hypoxemia and potential danger for the patient. |
| Polycyclic | Multiple sleep periods and wake periods in a 24-hour day. |
| Polysomnogram | A sleep study performed in a lab. |
| Polysomnogram (PSG) | Continuous and simultaneous recording of physiological variables during sleep i.e. EEG EOG EMG (the three basic stage scoring parameters) EKG respiratory air flow respiratory excursion lower limb movement and other electrophysiological variables. |
| Polysomnograph | Biomedical instrument for the measurement of multiple physiological variables of sleep. |
| Polysomnographic Technologist | Health care professional trained in performing diagnostic sleep studies. |
| POLYSOMNOGRAPHY (ply-som-nog-gra-fie) | Simply means a recording of lots of things during sleep. Has come to mean recording at least EEG EMG and EDG all night. |
| POPWN | Parent of a person w/ Narcolepsy |
| Portable monitoring | A home sleep test |
| Post-Prandial Drowsiness | Sleepiness that occurs after a meal usually lunch. |
| Post-Traumatic Stress Disorder | Re-experiencing of a traumatic event in the form of repetitive dreams recurrent and intrusive daytime recollections and/or dissociative flashback episodes. |
| Premature morning awakening | Early termination of the sleep period in a sleep maintenance DIMS due to inability to return to sleep after the last of several awakenings. |
| Prescribed CPAP Pressure | Pressure(s) or settings determined by a CPAP titration sleep study which a physician prescribes for a patient's CPAP therapy machine. |
| PS | Paradoxical Sleep |
| PSG | Polysomnogram |
| PSG | A polysomnogram |
| PTSD | Post traumatic stress disorder |
| Pulse Oximetry | Non-invasive measure of oxygen saturation; that is the amount of oxygen saturated in the hemoglobin in terms of percentage; not as accurate as the values obtained from an arterial blood gases (ABG) test and should only be used as a gauge of oxygenation. Normal ranges are between 95-100%. |
| Pump or blower | Main unit developing the pressure. |
| PWC | Persons w/CFIDS |
| PWN | Person (People) with Narcolepsy |
| PWON | Person (People) without Narcolepsy |
