Signs and Symptoms in Psychiatry
Mohamed Ahmed Abd El-Hay in Essentials of Psychiatric Assessment, 2018
Normal hallucination may be met in the following conditions: Hypnagogic and hypnopompic hallucinations: false perception occurring while falling asleep and while awakening from sleep, respectively. Although frightening, these perceptual disturbances are naturally occurring phenomena (Cheyne & Girard, 2007), and are generally considered non-pathological. They occur during drowsiness, are discontinuous, appear to force themselves on the subject, and do not form part of a dream. They may take the form of geometrical designs, faces, and figures or scenes from nature. Auditory hallucination may take the form of animal noises, musical sounds, hearing one’s name being called, and sometimes the voice says a sentence or phrase that has no meaning. In a subject deprived of sleep, a hypnagogic state may occur, in which case there are hallucinatory voices, visual hallucinations, ideas of persecution, and no insight into the morbid phenomenon. This condition usually disappears after the subject has had a good sleep.After physical stimulation of sense organs: e.g., flashes after pressing the eyeball.
Common sleep disorders
Ravi Gupta, S. R. Pandi Perumal, Ahmed S. BaHammam in Clinical Atlas of Polysomnography, 2018
Narcolepsy is a relatively rare autoimmune disease. It has pentad of clinical features including:Irresistible attacks of sleep, which is usually present in all patients. The other feature of narcolepsy is not present in all patients.Cataplexy, characterized by sudden bilateral loss of muscle tone brought on by emotions, which can be limited to certain muscles or generalized, resulting in falling down. Full consciousness during cataplexy. Cataplexy is pathognomonic for narcolepsy and is not present in all narcolepsy patients. If cataplexy is present, the patient has narcolepsy type 1. A diagnosis of narcolepsy without cataplexy (Narcolepsy type 2) is appropriate when excessive daytime sleepiness is present with REM phenomenology (hypnogogic hallucinations and sleep paralysis) but without cataplexy.Hypnagogic hallucination: Vivid dreams that occur at the transition from wakefulness to sleep (hypnagogic) or from sleep to wakefulness (hypnopompic).Sleep paralysis: It is a temporary inability to move or speak that happens when the patient is waking up or falling asleep.Interrupted fragmented sleep: Narcolepsy patients may complain of fragmented sleep.
Sleep–Wake Disorders
Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw in Hankey's Clinical Neurology, 2020
This event occurs at sleep onset or on awakening and is also thought to be due to an intrusion of REM sleep atonia into wakefulness. It is characterized by a terrifying feeling of being unable to move or speak despite being awake, and there is often a feeling of suffocation. Sleep paralysis rarely lasts more than a few seconds or minutes. About 40–80% of narcoleptic patients experience sleep paralysis, but in order to be considered a significant symptom, it must occur repeatedly, as it is also commonly reported as a rare event in the general population. Hypnagogic or hypnopompic hallucinations may occur along with the episode of sleep paralysis, thereby enhancing the frightening aspect of these spells.
Onward: The future orientation of constructive memory
Published in American Journal of Clinical Hypnosis, 2021
Ongoing studies showed a growing acceptance for the idea that changes in neural correlates are contributed to by activity, participation, and dreaming. A study by Dotta and Persinger (2009) explored the neurophysiology of dreams by testing a hypothesis that dreams involve the generation and perception of biophotons. The study of 40 discrete cases looked at different intervals in sleep and the convergence of geophysical and cerebral properties in seeking to better understand subjective sensations of time distortion and putative experience of information about future events. The authors summarize that if dreams and altered states of consciousness are actually the experiences of biophotons within the brain, it can help to explain enigmas associated with hypnosis, as well as hypnogogic and hypnopompic intrusions.
Emerging therapeutic targets for narcolepsy
Published in Expert Opinion on Therapeutic Targets, 2021
Marieke Vringer, Birgitte Rahbek Kornum
Narcolepsy has two subtypes: Patients with Narcolepsy type 1 (NT1) have cataplexy and hypocretin (Hcrt, also known as orexin) deficiency, while Narcolepsy type 2 (NT2) patients have neither cataplexy nor Hcrt deficiency [4,9,18]. Cataplexy attacks are brief episodes of muscle atonia during wake typically triggered by strong, mainly positive emotions. Other symptoms are sleep paralysis, hypnagogic, and hypnopompic hallucinations, and disturbed nocturnal sleep. These symptoms can be experienced by both NT1 and NT2 patients, but not every patient experience all the symptoms. Diagnosis requires nighttime and day-time polysomnography to rule out other sleep-wake disorders, objectify a short latency to fall asleep, and document at least two sleep onset REM (SOREM) periods [18]. Diagnosing NT2 can be challenging. This requires the presence of EDS and two SOREM periods but cataplexy and Hcrt deficiency should be absent. Due to the lack of clear biomarkers, diagnosis is mainly based on the exclusion of other sleep disorders [3,18,19].
Waveform Window #53: Hypersynchrony in REM Sleep
Published in The Neurodiagnostic Journal, 2023
Donna Young, Stacey D. Elkhatib Smidt, Sushanth Bhat, Sudhansu Chokroverty
Hypnagogic hypersynchrony is associated with drowsiness and is found in stages 1 and 2 of non-rapid eye movement (NREM) sleep. This hypersynchrony most often occurs in children under 13 years of age (Berry et al. 2020). Hypnopompic or post-arousal hypersynchrony is a similar but less frequently recognized entity to its hypnagogic equivalent that instead follows an arousal (Asadi-Pooya and Sperling 2019; Viswanathan et al. 2021). Neither of these hypersynchronous waveforms have been described in rapid eye movement (REM) sleep. We report a case of hypersynchrony during REM sleep.
Related Knowledge Centers
- Consciousness
- Hallucination
- Hypnagogia
- Rapid Eye Movement Sleep
- Sleep
- Sleep Paralysis
- Cenesthopathy
- NON-Rapid Eye Movement Sleep
- Dream
- Slow-Wave Sleep