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PubMed1988

Effect of alpha 1-adrenoceptors blockade with prazosin in canine narcolepsy.

The role of central alpha 1-adrenergic receptors in cataplexy was investigated in 4 narcoleptic poodles and 6 genetically narcoleptic Doberman pinschers. Treatment of narcoleptic dogs with prazosin, a selective alpha 1-adrenergic receptor blocker, exacerbated cataplexy in both narcoleptic dog breeds. Control and heterozygous Dobermans were not affected by the drug. Binding studies using [3H]prazosin revealed an increase in alpha 1-receptor binding apparently limited to the amygdala. The present study suggests that central alpha 1-adrenoceptors, whose role is still mostly unknown, play a fundamental role in controlling mechanisms involved in cataplexy and REM sleep.

Animals↗

PubMed2003

Distinct narcolepsy syndromes in Orexin receptor-2 and Orexin null mice: molecular genetic dissection of Non-REM and REM sleep regulatory processes.

Narcolepsy-cataplexy, a neurological disorder associated with the absence of hypothalamic orexin (hypocretin) neuropeptides, consists of two underlying problems: inability to maintain wakefulness and intrusion of rapid eye movement (REM) sleep into wakefulness. Here we document, using behavioral, electrophysiological, and pharmacological criteria, two distinct classes of behavioral arrests exhibited by mice deficient in orexin-mediated signaling. Both OX2R(-/-) and orexin(-/-) mice are similarly affected with behaviorally abnormal attacks of non-REM sleep ("sleep attacks") and show similar degrees of disrupted wakefulness. In contrast, OX2R(-/-) mice are only mildly affected with cataplexy-like attacks of REM sleep, whereas orexin(-/-) mice are severely affected. Absence of OX2Rs eliminates orexin-evoked excitation of histaminergic neurons in the hypothalamus, which gate non-REM sleep onset. While normal regulation of wake/non-REM sleep transitions depends critically upon OX2R activation, the profound dysregulation of REM sleep control unique to the narcolepsy-cataplexy syndrome emerges from loss of signaling through both OX2R-dependent and OX2R-independent pathways.

Animals↗

PubMed2001

Current concepts in the etiology, diagnosis and treatment of narcolepsy.

Background and purpose: Narcolepsy is the most common neurologic cause of excessive daytime sleepiness. Rapid eye movement (REM) sleep phenomena such as cataplexy, sleep paralysis and hypnagogic hallucinations can also occur. Cataplexy, a sudden bilateral loss of muscle tone usually brought on by emotional reactions such as excitement, is essentially unique to narcolepsy. Narcolepsy, which has a prevalence of 0.02-0.05% in the US, has a profound influence on the quality of life and safety of affected individuals.Patients and methods: The most characteristic and striking physiological abnormality observed in narcolepsy is the sleep-onset REM, or the occurrence of REM sleep at, or within 20 min of, the onset of sleep. The diagnosis is established by nocturnal polysomnography, and the Multiple Sleep Latency Test (MSLT).Results: Familial cases of narcolepsy have been reported, with the risk to first-degree relatives estimated at 1-2%; however, most cases are sporadic and the syndrome is generally believed to involve environmental factors acting on a specific genetic background. The observation of an HLA association in narcolepsy suggests that autoimmunity may play a role in the disorder. However, extensive studies have failed to find convincing evidence of an autoimmune process. Patients with narcolepsy have recently been shown to be deficient in hypocretin, also called orexin, in the cerebrospinal fluid and have a reduction in hypocretin cells in the lateral hypothalamus. This suggests that hypocretins could potentially provide a novel therapeutic approach to the treatment of narcolepsy.Conclusions: Although non-pharmacologic measures can be helpful in treating narcolepsy, most patients require pharmacotherapy that includes psychostimulants or modafinil. Cataplexy is controlled by tricyclic antidepressants or selective serotonin reuptake inhibitors.

Journal Article↗

PubMed2002

Diagnosing narcolepsy: validity and reliability of new diagnostic criteria.

BACKGROUND AND PURPOSE: No gold standard currently exists for the diagnosis of narcolepsy. Conventional diagnostic criteria are unwieldy and arbitrary. Clearly defined criteria for case selection are needed to compare the results of different studies. METHODS: We developed new clinical and neurophysiologic criteria for narcolepsy using four categories, based on the degree of diagnostic certainty. Category A is Definite Narcolepsy, Category B is Probable Narcolepsy (Laboratory Supported; two subgroups B1 and B2) and Category C is Probable Narcolepsy (Clinical). We assessed the charts of 69 new or established patients with narcolepsy seen consecutively in the Mayo Sleep Disorders Center and classified them according to our system. The human leucocyte antigen (HLA) DQB1*0602 status was determined for each patient as an indirect measure of validity. Two investigators independently assessed 30 charts to assess interrater reliability. We assessed additional 337 charts of patients with other hypersomnolence states to assess the specificity of our definitions. RESULTS: Seventy-four percent were positive for HLA DQB1*0602 (including 85% of those with cataplexy). Only 33% of those without cataplexy were HLA DQB1*0602 positive. The two investigators agreed on the classification of 29/30 patients (0.97 reliability). None of the 337 additional patients fulfilled criteria for narcolepsy, and specifically not for cataplexy. CONCLUSIONS: We conclude that our new research diagnostic criteria for narcolepsy possess high interrater reliability and appear valid descriptors of the syndrome, based on HLA typing. They may be useful in providing consistent criteria to compare different research studies.

Journal Article↗

PubMed2003

The narcoleptic borderland: a multimodal diagnostic approach including cerebrospinal fluid levels of hypocretin-1 (orexin A).

OBJECTIVES: Biological markers of narcolepsy with cataplexy (classical narcolepsy) include sleep-onset REM periods (SOREM) on multiple sleep latency tests (MSLT), HLA-DQB1*0602 positivity, low levels of cerebrospinal fluid (CSF) hypocretin-1 (orexin A), increased body mass index (BMI), and high levels of CSF leptin. The clinical borderland of narcolepsy and the diagnostic value of different markers of narcolepsy remain controversial and were assessed in a consecutive series of 27 patients with hypersomnia of (mainly) neurological origin. METHODS: Diagnoses included classical narcolepsy (n=3), symptomatic narcolepsy (n=1), narcolepsy without cataplexy (n=4), idiopathic hypersomnia (n=5), hypersomnia associated with psychiatric disorders (n=5), and hypersomnia secondary to neurological disorders or of undetermined origin (n=9). Clinical assessment included BMI, Epworth Sleepiness Scale (ESS), Ullanlinna Narcolepsy Scale (UNS), and history of REM-symptoms (sleep paralysis, hallucinations). HLA-typing, electrophysiological studies (conventional polysomnography, MSLT, 1-week actigraphy), and measurements of CSF levels of hypocretin and leptin were also performed. RESULTS: Hypocretin-1 was undetectable in three patients with classic narcolepsy and detectable in the remaining 24 patients. Other narcoleptic markers also frequently found in patients without narcolepsy included ESS>14 (78% of 27 patients), UNS>14 (75%), REM symptoms (30%), sleep latencies on MSLT<5 min (41%), >/=2 SOREM (30%), DQB1*0602 positivity (52%), BMI>25 (52%), and increased CSF leptin (48%). Hypersomnia was documented by an increased time 'asleep' in 41% of patients. Overlapping clinical and electrophysiological findings were seen mostly in patients with narcolepsy without cataplexy, idiopathic hypersomnia, and psychiatric hypersomnia. CONCLUSIONS: (1) Hypocretin dysfunction is not the 'final common pathway' in the pathophysiology of most hypersomnolent syndromes that fall on the borderline for a diagnosis of narcolepsy. (2) The observed overlap among these hypersomnolent syndromes implies that current diagnostic categories are not entirely unambiguous. (3) A common hypothalamic, hypocretin-independent dysfunction may be present in some of these syndromes.

Adolescent↗

PubMed2026

Safety, tolerability, and efficacy of alixorexton, a selective orexin 2 receptor agonist for narcolepsy type 1 (Vibrance-1): a randomised, double-blind, placebo-controlled, phase 2 trial.

BACKGROUND: The clinical potential of orexin 2 receptor (OX2R) agonism for improving measures of wakefulness and cataplexy in patients with narcolepsy type 1 has been described in a phase 2 study. Here, we aimed to evaluate the safety, tolerability, and efficacy of alixorexton, another oral OX2R agonist, in narcolepsy type 1. METHODS: In this randomised, double-blind, placebo-controlled, phase 2 trial, adult participants (aged 18-70 years) with narcolepsy type 1 were recruited from 46 hospitals and private research centres across the USA, Europe, and Australia. Participants were centrally randomly assigned (1:1:1:1) in blocks of four via an interactive response technology system stratified by region and baseline weekly cataplexy rate (WCR) to receive 4 mg, 6 mg, or 8 mg tablets of alixorexton or placebo once daily for 6 weeks, followed by an optional 7-week open-label extension. Participants had narcolepsy type 1, diagnosed per the International Classification of Sleep Disorders, Third Edition, and confirmed by overnight polysomnography and the Multiple Sleep Latency Test or cerebrospinal hypocretin-1 concentrations. The sponsor, assessors, investigators, and participants were masked during the randomised double-blind treatment period. Efficacy and safety assessments were conducted in participants who received at least one dose of study drug. The primary endpoint was change from baseline to week 6 in mean sleep latency (MSL) on the Maintenance of Wakefulness Test (MWT). Safety endpoints included treatment-emergent adverse events. This trial was registered with ClinicalTrials.gov (NCT06358950) and is completed. FINDINGS: Between May 24, 2024, and May 5, 2025, 153 individuals were screened and 92 participants were randomly assigned to receive alixorexton 4 mg (n=23), 6 mg (n=22), 8 mg (n=24), or placebo (n=23). Mean age was 33·5 years (SD 12·1), 57 (62%) were women, and 35 (38%) were men. At week 6, the observed MSL on the MWT was 2·3 min (SD 2·7) for placebo, 24·0 min (8·7) for alixorexton 4 mg, 25·9 min (9·4) for 6 mg, and 28·2 min (11·4) for 8 mg. Alixorexton improved MSL on the MWT, with a least-squares mean placebo-corrected change from baseline of 22·2 min (95% CI 17·2-27·2) for alixorexton 4 mg, 24·1 min (19·0-29·1) for 6 mg, and 26·0 min (21·0-31·0) for 8 mg (adjusted p=0·0099 for 4 mg, adjusted p<0·0001 for 6 mg and 8 mg). Treatment-emergent adverse events occurring in at least 5% of participants given alixorexton and more frequently than those given placebo up to week 6 were pollakiuria (38 [55%]), insomnia (19 [28%]), salivary hypersecretion (17 [25%]), micturition urgency (ten [14%]), blurred vision (ten [14%]), and hyperhidrosis (five [7%]). INTERPRETATION: In this phase 2 trial, once-daily oral alixorexton provided clinically meaningful improvements at 6 weeks for participants with narcolepsy type 1, including in wakefulness, excessive daytime sleepiness, and cataplexy. The treatment was generally well tolerated, with adverse events consistent with the known on-target effects of OX2R agonists. Together, these findings support the further phase 3 evaluation of alixorexton as a potential therapeutic option for people with narcolepsy type 1. FUNDING: Alkermes.

Humans↗

PubMed1994

Controversies in the diagnosis of narcolepsy.

The diagnosis of narcolepsy can be problematic. Most sleep laboratories use polygraphic testing to establish the diagnosis. One polygraphic recording followed by a single multiple sleep latency test (MSLT) is used to differentiate the causes of syndromes with complaints of daytime somnolence. Prospective investigations have demonstrated that patients with periodic leg movements or upper airway resistance syndrome may present abnormal sleep latencies and more than one sleep onset rapid eye movement period (SOREMP) during MSLT. On the other hand, investigations of patients with daytime sleepiness and cataplexy have shown that the MSLT may not show more than one SOREMP. The combination of history of cataplexy and more than one SOREMP during MSLT is the best clinical determinant of narcolepsy. History of daytime sleepiness and presence of more than one SOREMP during MSLT, however, is a poorer discriminant of narcolepsy than history of cataplexy, particularly in an aging population.

Adolescent↗

PubMed2002

Search for neuron-specific and nonneuron-specific antibodies in narcoleptic patients with and without HLA DQB1*0602.

STUDY OBJECTIVES: Narcolepsy is strongly associated with the presence of HLA DQB1*0602. This and other evidence suggests that human narcolepsy is an autoimmune disease. This is in distinction to that found in canine models where hypocretin receptor 2 mutations are etiologic. We decided to test for the presence of several neuron-specific and organ-specific autoantibodies to see if they were present in HLA DQB1*0602-associated or cataplexy-associated narcolepsy or could serve as a serologic marker of the illness. DESIGN: We tested for N-type and P/Q-type voltage-gated calcium-channel antibodies, neuronal nicotinic acetylcholine receptor alpha3 subunit, acetylcholine receptor-binding antibodies, striated muscle antibodies, Type 1 Purkinje cell cytoplasmic antibodies, types 1 and 2 antineuronal nuclear antibodies and amphiphysin antibodies, GAD-65 antibody, and thyroid microsomal and thyroglobulin antibodies in the serum of 43 patients with or without cataplexy, 41 with known HLA status. SETTING: Narcoleptic subjects were recruited from the Mayo Sleep Disorders Center. PARTICIPANTS: N/A. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: No antibody test yielded significantly positive results for the group as a whole or for subgroups of patients with cataplexy or positive HLA DQB1*0602 status. CONCLUSIONS: These results do not support the hypothesis that narcolepsy is an autoimmune disease. However, it is possible that the autoimmune attack is very selective and does not involve the epitopes measured in this study. Recent findings that the hypocretin neurotransmission system is involved in animal models of narcolepsy should lead to research to look for antibodies directed against components of the hypocretin neurotransmission system in narcolepsy.

Adult↗

PubMed1995

Altered distribution of cholinergic cells in the narcoleptic dog.

Narcolepsy is characterized by excessive sleepiness and episodes of cataplexy brought on by emotional excitation. Cataplexy and sleep paralysis have been hypothesized to be produced by the triggering during waking of brain stem cholinergic mechanisms normally acting to induce atonia in REM sleep. We hypothesized that narcoleptics have an abnormal number of LDT and/or PPN cholinergic neurons. A comparison was made of cholinergic cell numbers in the brain stems of normal and narcoleptic canines. Cholinergic neurons were identified by NADPH-diaphorase histochemistry. We found increased numbers of cholinergic neurons at the R6-R7 level of the LDT and PPN in narcoleptic canines. This abnormality can explain alterations in cholinergic receptor number, acetylcholine release, and the occurrence of cataplexy and sleep paralysis that characterize narcolepsy.

Acetylcholine↗

PubMed2005

Concomitant loss of dynorphin, NARP, and orexin in narcolepsy.

BACKGROUND: Narcolepsy with cataplexy is associated with a loss of orexin/hypocretin. It is speculated that an autoimmune process kills the orexin-producing neurons, but these cells may survive yet fail to produce orexin. OBJECTIVE: To examine whether other markers of the orexin neurons are lost in narcolepsy with cataplexy. METHODS: We used immunohistochemistry and in situ hybridization to examine the expression of orexin, neuronal activity-regulated pentraxin (NARP), and prodynorphin in hypothalami from five control and two narcoleptic individuals. RESULTS: In the control hypothalami, at least 80% of the orexin-producing neurons also contained prodynorphin mRNA and NARP. In the patients with narcolepsy, the number of cells producing these markers was reduced to about 5 to 10% of normal. CONCLUSIONS: Narcolepsy with cataplexy is likely caused by a loss of the orexin-producing neurons. In addition, loss of dynorphin and neuronal activity-regulated pentraxin may contribute to the symptoms of narcolepsy.

Aged↗

PubMed2002

Benefits and risks of pharmacotherapy for narcolepsy.

Narcolepsy is a life-long central nervous system (CNS) syndrome characterised by excessive sleepiness, cataplexy, sleep paralysis, hypnagogic hallucinations and disturbed night-time sleep. Unsuccessfully treated narcolepsy confers increased risks on patients and on society due to the patient's increased chance of becoming involved in vehicle crashes and workplace mishaps. The syndrome may be diagnosed by a clinical history positive for cataplexy and excessive daytime sleepiness and negative for other more common sleep disorders such as sleep apnoea and sleep deprivation. Night-time polysomnography and multiple sleep latency testing are helpful in differentiating narcolepsy from other sleep problems. Recent data from canine, murine, and human forms of narcolepsy indicate that genetically or developmentally mediated deficits in the hypocretin neurotransmitter system may cause some, but not all, forms of narcolepsy. Pharmacotherapy for narcolepsy is required to control symptoms and involves the use of CNS stimulants or modafinil to control sleepiness and antidepressant medications or sodium oxybate to control cataplexy. Modafinil and sodium oxybate have been developed and approved specifically for the indication of narcolepsy based on large, double-blind, placebo-controlled, parallel group efficacy and safety studies. The efficacy of drugs in the treatment of narcolepsy is variable from patient to patient and usually associated with adverse effects that can limit patient compliance and, therefore, symptom control. Nevertheless, the benefits of pharmacotherapy are judged to outweigh the risks to the patient. The favourable benefit-risk ratio of pharmacotherapy is greater if one considers the reduced risk to society of vehicle crashes and workplace mishaps that might be precipitated by attentional lapses or sleep attacks in the untreated or under-treated patient with narcolepsy.

Animals↗

PubMed2000

RTMS induces brief events of muscle atonia in patients with narcolepsy.

STUDY OBJECTIVES: To investigate the effect of repetitive transcranial magnetic stimulation (rTMS) in patients with narcolepsy. DESIGN: Using rTMS, three patients with narcolepsy and cataplexy were investigated with and without their anticataplectic medication. rTMS of the motor cortex was performed at an intensity of 110% of resting motor threshold, a frequency of 20 Hz, and a duration of 2s. EMG activity was recorded for both the right and left first dorsal interosseous muscle (FDI). Eight healthy controls were also investigated under the same conditions. SETTING: The study was carried out in the sleep laboratory of the Neurology Department (University of Aachen). PATIENTS: One female and two male patients with narcolepsy/cataplexy. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: In three narcoleptic patients, after three days of not taking their usual anticataplectic medication, rTMS of the motorcortex induced an interruption of voluntary EMG activity in the FDI. EMG reduction lasted from 0.6 to 3.5s and was more pronounced in the hand contralateral to the stimulated hemisphere. This result was not observed in these patients when taking their regular medication nor in the normal controls. Stimulation of other cortical areas, as well as stimulation of the peripheral nervous system, did not induce muscle weakness episodes. CONCLUSIONS: We postulate that rTMS of the descending voluntary motor pathway triggers muscle atonia similar to cataplexy by indirectly activating the mechanisms responsible for the generation of muscle atonia during REM sleep and cataplexy. We conclude that rTMS, in the future, might prove to be a useful addition to the diagnostic repertoire for narcolepsy.

Adult↗

PubMed2001

Methylphenidate and narcolepsy: new indication. When modafinil fails.

(1) Narcolepsy (daytime bouts of drowsiness) is sometimes associated with cataplexy, and can be incapacitating. The best-assessed treatment is modafinil, which has no demonstrated efficacy on cataplexy. (2) After many years of off-license use in the treatment of narcolepsy, methylphenidate is now licensed for this indication in France. (3) According to the results of our literature search, which includes a clinical expert report from Novartis Pharma, the file on methylphenidate in narcolepsy is mainly based on "clinical experience": only three case series, totalling fewer than 200 patients, have been published. (4) These non comparative studies suggest an effect of high dose methylphenidate on daytime drowsiness and cataplexy. (5) The adverse effects of methylphenidate are those of amphetamine psychostimulants, i.e. mainly neuropsychological disorders, cardiovascular effects, loss of appetite and a limited risk of excessive use by some patients.

Benzhydryl Compounds↗

PubMed2002

A randomized, double blind, placebo-controlled multicenter trial comparing the effects of three doses of orally administered sodium oxybate with placebo for the treatment of narcolepsy.

STUDY OBJECTIVES: To evaluate and compare the efficacy and safety of three doses of sodium oxybate and placebo for the treatment of narcolepsy symptoms. DESIGN: A multicenter, double blind, placebo-controlled trial. SETTING: N/A. PARTICIPANTS: Study subjects were 136 narcolepsy patients with 3 to 249 (median 21) cataplexy attacks weekly. INTERVENTIONS: Prior to baseline measures, subjects discontinued anticataplectic medications. Stable doses of stimulants were permitted. Subjects were randomized in blinded fashion to receive 3, 6, or 9 g doses of sodium oxybate or placebo taken in equally divided doses upon retiring to bed and 2.5-4 hours later for 4 weeks. MEASUREMENTS AND RESULTS: Disease symptoms and adverse events were recorded in daily diaries. The primary measure of efficacy was the change from baseline in weekly cataplexy attacks. Secondary measures included daytime sleepiness using the Epworth Sleepiness Scale (ESS), inadvertent daytime naps/sleep attacks and nighttime awakenings. Investigators assessed changes in disease severity using Clinical Global Impression of Change (CGI-c). Compared to placebo, weekly cataplexy attacks were decreased by sodium oxybate at the 6 g dose (p=0.0529) and significantly at the 9 g dose (p=0.0008). The ESS was reduced at all doses, becoming significant at the 9 g dose (p=0.0001). The CGI-c demonstrated a dose-related improvement, significant at the 9 g dose (p=0.0002). The frequency of inadvertent naps/sleep attacks and the nighttime awakenings showed similar dose-response trends, becoming significant at the 9 g dose (p=0.0122 and p=0.0035, respectively). Sodium oxybate was generally well-tolerated at all three doses. Nausea, headache, dizziness and enuresis were the most commonly reported adverse events. CONCLUSIONS: Sodium oxybate significantly improved symptoms in patients with narcolepsy and was well tolerated.

Adjuvants, Anesthesia↗

PubMed2003

[Clinical and sleep EEG monitoring characteristics and long-term follow-up study on narcolepsy].

OBJECTIVE: Narcolepsy is a sleep disorder characterized by excessive daytime sleepiness, cataplexy, hypnagogic hallucination and sleep paralysis, with abnormal characteristics of shorter rapid eye movement (REM) sleep latency. The management of the patients is very important. The present study focused on the clinical characteristics, diagnostic methods and long-term prognosis of this particular syndrome. METHODS: The clinical data of 39 narcoleptic children were analyzed. Sleep EEG monitoring was performed in all patients. Among the 39 cases, 23 were followed up. RESULTS: All the patients manifested with excessive daytime sleepiness, with disrupted nocturnal sleep occurring in 35 cases. Cataplexy appeared in 36 cases, and sleep paralysis in 9, hypnagogic hallucination in 19, and automatic behavior in 6 cases, respectively. Sleep EEG monitoring demonstrated a short mean sleep latency (< 5 minutes) and two or more sleep onset REM periods (SOREMPs) in 38 cases. Twenty-three of the 39 cases were followed-up. Seventeen cases were followed-up for over one year. The longest follow-up duration was 14 years. Methylphenidate was administered in 10 cases. The excessive daytime sleepiness had been improved in 7 cases (70%). No obvious adverse effects were found. Psychosocial and academic problems appeared in most cases. CONCLUSION: Narcolepsy is a chronic neurological disorder. A definite diagnosis is established when the symptoms of cataplexy and excessive daytime sleepiness occur in association with the characteristic findings on sleep EEG monitoring. Appropriate drug therapy and psychosocial management are of help for such patients. Stimulant medication is an important component of the overall treatment program. A comprehensive approach is necessary to meet the needs of children with narcolepsy. Family education and emotional support are key elements in the management plan. The overall goal for managing childhood narcolepsy is to assist the child and family in achieving optimal quality of life.

Adolescent↗

PubMed1993

Narcolepsy.

Narcolepsy afflicts more than 200,000 Americans. In most cases the first symptom of the disease, excessive daytime sleepiness, develops during childhood or adolescence. This initial presentation is followed by cataplexy or other auxiliary symptoms several years later. Not infrequently, many years pass before the proper diagnosis of narcolepsy is made. Narcolepsy is a chronic lifelong disease without periods of remission. Excessive daytime sleepiness, inappropriate sleep attacks, and the pathognomonic symptom of cataplexy, are diagnostic of narcolepsy. Confirmation of the disease is made by a multiple sleep latency test. Although still not being used for diagnostic purposes, the association between narcolepsy and the human leukocyte group A (HLA) antigen DR2 is the strongest so far described for any disease. With the help of psychosocial support, therapeutic naps, and medications, the patient with narcolepsy may be able to lead a normal life. Methylphenidate and imipramine are the two most widely used drugs for the treatment of daytime somnolence and cataplexy, respectively.

Diagnosis, Differential↗

PubMed1997

[Diagnostic difficulties in the narcolepsy-catalepsy syndrome: with reference to our series of cases].

The narcolepsy-cataplexy syndrome is a disorder of unknown aetiology, characterized by excessive daytime sleepiness associated with cataplexy and other REM sleep phenomena. Diagnosis is based on the clinical findings, although this may be difficult especially with respect to confirming the cataplexy. Objective tests, such as typing for HLA, DR2DQ1 (DRw15DQw6, WHO90) and above all TMLS (average latency < 5 mn and two or more onsets of sleep in the phases REM and SOREMP's) is of great help. However, the exact diagnostic significance of some aspects of these tests and their parameters is still under discussion. In this paper we review our series of cases consisting of fourteen patients who fulfil the clinical diagnostic criteria required in the ICSD-1990. TMLS and HLA typing was done for all. Of the HLA types, DQ1 was present in all our patients, unlike DR2 which was not found in two patients. Regarding TMLS, the average latency < 5 mn is a parameter met by all cases, although one did not have SOREMP's. The findings of the objective tests done on our patients are in agreement with those described by other authors. They underline the significance of the support they lend to the diagnosis. However, they are not the definite answer to the problem.

Adult↗

PubMed1997

Circadian distribution of rest/activity in narcoleptic and control dogs: assessment with ambulatory activity monitoring.

Like human narcoleptics, narcoleptic dogs display cataplexy, fragmented sleep and excessive daytime sleepiness. Cataplexy in dogs can easily be quantified using a simple behavioural bioassay, the Food Elicited Cataplexy Test. In contrast, daytime sleepiness and fragmented sleep are more difficult to measure, as long-term, labour-intensive polygraphic recordings in surgically-implanted animals are needed. In the current study, 24-h rest/activity patterns in genetically narcoleptic, asymptomatic heterozygous and control Dobermans were compared using small sized ambulatory activity monitoring devices under 12-h light/dark conditions. Control and heterozygous dogs were found to be more active during the light period than during the dark period, thus demonstrating a clear 24-h rest/activity cycle. In contrast, narcoleptic dogs were relatively inactive during the light period and did not show a clear rest/activity pattern, a result similar to that of human narcoleptics. Considering the fact that narcoleptic dogs show shorter sleep latency and sleep significantly more during the daytime than control dogs, the decrease in activity in narcoleptic dogs during the daytime is most likely a reflection of increased daytime napping in these animals. Ambulatory activity monitoring may be a useful non-invasive method for future pharmacological and development studies in the narcoleptic canine model.

Animals↗