Narcolepsy (and Cataplexy)
Alexander R. Toftness in Incredible Consequences of Brain Injury, 2023
If somnolence is like a switch that turns a person's consciousness off and forces them to sleep, then cataplexy is like a switch for a person's muscles that forces them to relax. During an attack of cataplexy, the person loses the ability to move or tone their muscles, resulting in a drooping face, sagging jaw, tongue protrusion, and may cause the person to fall down due to the loss of motor control in the legs (Bassetti et al., 2019). These difficulties in moving muscles are similar to what happens in sleep paralysis, and it has been theorized that cataplexy is similar to REM sleep occurring while you are fully awake (Gauci et al., 2017). Cataplexy doesn't occur during the transition between sleeping and wakefulness like sleep paralysis does—cataplexy happens throughout the course of the person's waking day. Cataplexy attacks can be complete and affect all muscles in the body, or partial, in which they affect only a part of the body such as the face or neck. These attacks usually last for seconds—or a minute or two—and, importantly, the person remains fully awake and conscious the whole time (Adamantidis et al., 2020).
The Legal Aspects of Narcolepsy
Meeta Goswami, Charles P. Pollak, Felissa L. Cohen, Michael J. Thorpy, Neil B. Kavey, Austin H. Kutscher, Jill C. Crabtree in Psychosocial Aspects of Narcolepsy, 2015
Narcolepsy1 is defined as recurrent, uncontrollable, brief episodes of sleep, often associated with hypnagogic hallucinations, cataplexy, and sleep paralysis.2 Hypnagogic hallucinations, which occur in 25-54 percent of narcoleptic persons, consist of a vivid dream-like state with false visual and auditory hallucinations.3 Cataplexy is a sudden loss of muscle tone, usually precipitated by emotional stimulation such as laughter, anger, or fear. Approximately 60 percent of patients with narcolepsy experience episodes of cataplexy.4 These episodes of cataplexy may last from a few seconds to as long as 30 minutes. Cataplexy is virtually pathognomonic or distinctively characteristic of narcolepsy, although its onset is often several years after symptoms of excessive sleepiness begin.5 Sleep paralysis can occur with sleep onset or awakening. The brain wakes up while the body remains in rapid eye movement sleep. Thus, the individual appears peacefully asleep but can actually be experiencing a frightening dream.6
Epilepsy and Sleep Disorders
John W. Scadding, Nicholas A. Losseff in Clinical Neurology, 2011
Some of these represent REM sleep phenomena such as hypotonia/atonia, and dreams occurring at inappropriate times. Cataplexy is a sudden decrease in voluntary muscle tone (especially jaw, neck and limbs) that occurs with sudden emotion like laughter, elation, surprise or anger. This can manifest as jaw dropping, head nods or a feeling of weakness or, in more extreme cases, as falls with ‘paralysis’ lasting sometimes for several minutes. Consciousness is preserved. Cataplexy is a specific symptom of narcolepsy, although narcolepsy can occur without cataplexy. Sleep paralysis and hypnagogic hallucinations are not specific and can occur in other sleep disorders and with sleep deprivation (especially in the young). Both these phenomena occur shortly after going to sleep or on waking. Sleep paralysis is a feeling of being awake, but unable to move. This can last for several minutes and is often very frightening, so can be associated with a feeling of panic. Hypnagogic/hypnapompic hallucinations are visual or auditory hallucinations occurring while dozing/falling asleep or on waking; often the hallucinations are frightening, especially if associated with sleep paralysis.
Pharmacological options for narcolepsy: are they the way forward?
Published in Expert Review of Neurotherapeutics, 2023
Cataplexy consists of emotionally triggered sudden and transient involuntary loss of skeletal muscle tone with preserved consciousness. Weakness is usually triggered by strong positive emotions, such as laughter, amusement, surprise, and joking, and less commonly triggered by anger, frustration, fear, stress, or orgasm [2,13,15–19]. As cataplexy is the most pathognomonic feature of narcolepsy, it is important to be familiar with its diverse manifestations. Cataplexy attacks range from partial muscle weakness to complete paralysis [13]. They are always bilateral, although one side may be more affected. Attacks typically last from several seconds to several minutes; rarely, they may last for hours (status cataplecticus) [13, 18, 20]. Common manifestations include eyelid ptosis, mouth opening, tongue thrusting that abruptly interrupts smiling or other facial expressions, facial jerks, contractions and grimaces, jaw tremor, or dysarthria before a decrease or loss of muscle tone (head drop, trunk fall, impaired hand dexterity and/or dropping items), and impaired balance or falling due to knee buckling [13,18,20]. Cataplexy can be mistaken for drop attacks, transient ischemic attacks, postural hypotension, vestibular disorders, akinetic seizures, and psychiatric disorders [1,18,20].
Pitolisant for the treatment of cataplexy in adults with narcolepsy
Published in Expert Opinion on Orphan Drugs, 2021
Gerard J. Meskill, Ulf Kallweit, Donna Zarycranski, Christian Caussé, Olivier Finance, Xavier Ligneau, Craig W. Davis
In the absence of adequate hypocretin activity, patients with NT1 experience not only EDS but also REM sleep dysregulation, which manifests as elements of REM sleep occurring during wakefulness or sleep-wake transitions (i.e. cataplexy, sleep paralysis, hypnagogic hallucinations) [2,9,10]. Muscle atonia is a normal characteristic of REM sleep [18]. During wakefulness, muscle tone is maintained by activity in several neural pathways, including REM sleep-suppressing neurons in the ventrolateral periaqueductal gray and lateral pontine tegmentum (vlPAG/LPT), norepinephrine neurons of the locus coeruleus, serotonin neurons of the dorsal raphe nucleus, and acetylcholine neurons in the lateral dorsal tegmental/pedunculopontine tegmental (LDT/PPT) nuclei [10,12,18–20]. Cataplexy is thought to result from the intermittent activation of REM sleep atonia circuitry, which allows the intrusion of this REM sleep manifestation (i.e. muscle atonia) into wakefulness [9,10,18,21]. Strong emotions activate neural pathways in the prefrontal cortex and amygdala, and hypocretin functions to suppress atonia during normal wakefulness [12,20,21]. Due to the lack of adequate hypocretin activity in patients with NT1, the experience of strong emotions can lead to disinhibition of neurons in the REM sleep atonia circuit and reduced activity in neural pathways that maintain normal muscle tone, which results in the occurrence of muscle atonia during wakefulness (i.e. cataplexy; Figure 1) [9,10,12,18,20,21].
The evolution of the narcolepsy concept in Russia: A historical view
Published in Journal of the History of the Neurosciences, 2021
A. Kuts, M. Poluektov, C. L. A. Bassetti
Despite precise descriptions of typical narcolepsy with cataplexy by such authors as Henneberg, Löwenfeld, and Redlich, the true clinical spectrum and nature of the disease remained controversial until the 1920s. In a famous controversy that took place in the journal Brain, Adie (1926) suggested narcolepsy to be a specific disease with excessive daytime sleepiness and cataplexy as the main manifestations. He considered narcolepsy an “endocrine-nervous” disorder affecting people with changed constitutional states of alertness in the brain predisposing them to excessive inhibition and fatigue. Conversely, Wilson (1928) did not consider narcolepsy a specific disease. Both agreed in considering an inhibitory mechanism of the brain as an explanation for both sleep and cataplexy attacks.
Related Knowledge Centers
- Awareness
- Hypnagogia
- Muscle
- Orexin
- Syndrome
- Visual Perception
- Paralysis
- Narcolepsy
- Arousal
- Weakness