China
Africa
Explore chapters and articles related to this topic
Parasomnias
Published in Stanley R. Resor, Henn Kutt, The Medical Treatment of Epilepsy, 2020
Hypnagogic hallucinations are visual or auditory hallucinations at the transition between wakefulness and sleep. They may occur at the transition of wakefulness to stage 1 sleep or could represent a brief intrusion of REM sleep-related phenomena into wakefulness. They may be accompanied by sleep paralysis, a manifestation of REM-related muscular atonia. The hallucinations have no independent medical significance and rarely require treatment, but may be associated with narcolepsy so that persistent and unexplained episodes should encourage an evaluation for that disorder. Use of or acute withdrawal from REM-suppressant drugs and chronic sleep deprivation can also elicit this phenomenon.
Sleep Promoting Improvement of Declarative Memory
Published in Bahman Zohuri, Patrick J. McDaniel, Electrical Brain Stimulation for the Treatment of Neurological Disorders, 2019
Bahman Zohuri, Patrick J. McDaniel
To measure the voltage of the electrical impulses being given off by the brain’s neurons, technicians can use an EEG Machine (See Chapter 6 of this book). The type of brain wave, defined by amplitude and frequency, helps determine the type of sleep that the sleeper is experiencing. The state of falling asleep is called the hypnagogic state.
The biological and evolutionary foundations of sleep and dreams
Published in Frederick L. Coolidge, Ernest Hartmann, Dream Interpretation as a Psychotherapeutic Technique, 2018
Frederick L. Coolidge, Ernest Hartmann
One of the more debatable experiences during sleep may occur before or during stage 1 sleep, and that is the hypnagogic state. This few-minutes-long period is well known, however, and occurs when we start to experience the transition from wakefulness to sleep. Usually people report a floating sensation accompanied by a slow loosening of thoughts and weird or bizarre imagery. It is debatable because the EEG correlates of these weird thought fragmentations are not well established nor have the subject’s reports been analyzed along with EEG monitoring.
Clarithromycin-Induced Visual Hallucinations
Published in Neuro-Ophthalmology, 2022
Daragh McGee, Cathal Hanley, Audrey Reynolds, Shane Smyth
Well-formed, dreamlike, colourful hallucinations that are more prominent in the dark can occur with brainstem or thalamic lesions (peduncular hallucinosis). Although the lack of acute findings on MRI argues against this diagnosis, the pontine microbleed is notable in this context. A review of five cases of peduncular hallucinosis found abnormal sleep behaviour in all cases. It noted the similar vivid, realistic, and affective quality of hallucinations that occur in Parkinson’s disease with rapid eye movement sleep abnormalities, narcolepsy-cataplexy-complex, Lewy-body dementia, and in the hypnagogic state.6 A proposed mechanism for clarithromycin-induced hallucinations, discussed below, is disruption to the reticular activating system. Young et al. proposed that neurotoxic insults can be seen as a ‘stress test’ of this system4 and clarithromycin could be seen as a functional insult to our patient’s brain, primed by an historic microbleed and/or chronic microvascular ischaemic changes. Her vision had been good since prior cataract surgery and, in the context of an unremarkable ophthalmological assessment, it is unlikely that these were visual release hallucinations (Charles Bonnet syndrome). The onset of symptoms shortly after starting clarithromycin and resolution quickly after discontinuation make a toxic effect of the latter more likely.
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.