Misleading hallucinations in unrecognized narcolepsy

OBJECTIVE: To describe psychosis-like hallucinatory states in unrecognized narcolepsy. METHOD: Two patients with hypnagogic/hypnapompic hallucinations are presented. RESULTS: Both patients had realistic and complex - multi-modal and scenic-daytime sexual hallucinations leading, in the first case, to a legal procedure because of false accusation, and in the second, to serious workplace conflicts. Both patients were convinced of the reality of their hallucinatory experiences but later both were able to recognize their hallucinatory character. Clinical data, a multiple sleep latency test, polysomnography, and HLA typing revealed that both patients suffered from narcolepsy. CONCLUSION: We suggest that in unrecognized narcolepsy with daytime hypnagogic/hypnapompic hallucinations the diagnostic procedure may mistakenly incline towards delusional psychoses. Daytime realistic hypnagogic/hypnapompic hallucinations may also have forensic consequences and mislead legal evaluation. Useful clinical features in differentiating narcolepsy from psychoses are: the presence of other narcoleptic symptoms, features of hallucinations, and response to adequate medication.     

Concomitant narcolepsy and sleep apnea: report of a case

A case of concomitant narcolepsy and obstructive sleep apnea evaluated in a sleep disorder center is reported. Tracheostomy decreased the frequency of the apneas but the clinical and polysomnographic features of narcolepsy remained on 3 and 6 months post-surgical follow-ups. These findings support the need for systematic use of all-night polysomnography and multiple sleep latency test in patients with excessive daytime sleepiness.     

Daytime REM sleep in Parkinson's disease

BackgroundPrevious studies have demonstrated both clinical and neurochemical similarities between Parkinson's disease (PD) and narcolepsy. The intrusion of REM sleep into the daytime remains a cardinal feature of narcolepsy, but the importance of these intrusions in PD remains unclear. In this study we examined REM sleep during daytime Maintenance of Wakefulness Testing (MWT) in PD patients.MethodsPatients spent 2 consecutive nights and days in the sleep laboratory. During the daytime, we employed a modified MWT procedure in which each daytime nap opportunity (4 per day) was extended to 40 min, regardless of whether the patient was able to sleep or how much the patient slept. We examined each nap opportunity for the presence of REM sleep and time to fall asleep.ResultsEleven of 63 PD patients studied showed 2 or more REM episodes and 10 showed 1 REM episode on their daytime MWTs. Nocturnal sleep characteristics and sleep disorders were unrelated to the presence of daytime REM sleep, however, patients with daytime REM were significantly sleepier during the daytime than those patients without REM. Demographic and clinical variables, including Unified Parkinson's Disease Rating Scale motor scores and levodopa dose equivalents, were unrelated to the presence of REM sleep.ConclusionsA sizeable proportion of PD patients demonstrated REM sleep and daytime sleep tendency during daytime nap testing. These data confirm similarities in REM intrusions between narcolepsy and PD, perhaps suggesting parallel neurodegenerative conditions of hypocretin deficiency.     

HLA DR2 in narcolepsy with sleep-onset REM periods but not cataplexy.

To determine the association of HLA DR2 in patients with narcolepsy without cataplexy, a case-control study was performed. Patients receiving the diagnosis of narcolepsy without cataplexy had excessive daytime sleepiness (EDS) and polysomnographic findings consistent with narcolepsy but no clinical evidence of cataplexy. Of 28 patients identified, 12 agreed to return for HLA typing. Respondents did not differ from nonrespondents in demographic, clinical, or sleep laboratory data. The comparison group was 503 individuals, those 30 years and older, on the Michigan Kidney Transplant Registry. The odds ratio obtained from logistic regression indicated a strong association between narcolepsy without cataplexy and HLA DR2. To control for potential confounding variables, multivariate models were constructed to explore the joint effects of HLA DR2 and each one of the covariates (age, sex, and race), their possible combinations, and the effect of all three covariates. The odds ratios decreased minimally and the association between the disease and HLA DR2 remained significant.     

Degenerative pontine lesions in patients with familial narcolepsy

Background and purposeNarcolepsy is characterized by chronic excessive daytime sleepiness with episodic sleep attacks. There are several associated symptoms of narcolepsy: cataplexy (bilateral muscle weakness without loss of consciousness provoked by an emotional trigger, e.g. laughter), sleep paralysis and hypnagogic-hypnopompic hallucinations. Most cases are sporadic; familial narcolepsy contributes to only 1–5% of all cases. While most cases of narcolepsy are idiopathic and are not associated with clinical or radiographic evidence of brain pathology, symptomatic or secondary narcolepsy may occur occasionally in association with lesions caused by tumours, demyelination or strokes of the diencephalon, midbrain, and pons. There are some examples of non-specific brainstem lesions found in magnetic resonance imaging (MRI) in patients with idiopathic narcolepsy.Material and methodsThe authors present eleven patients from a five-generation family with many members who suffer from episodic excessive daytime sleepiness. Narcolepsy was diagnosed in 9 patients. Sleepiness was frequently associated with cataplexy, hypnagogic-hypnopompic hallucinations and sleep paralysis. Improvement in their clinical state was observed during the treatment with modafinil. All probands had MRI of the brain, routine blood tests, EEG, polysomnography, examination of the level of hypocretin in cerebrospinal fluid and evaluation by means of Epworth and Stanford Sleepiness Scales.ResultsIn 9 patients with narcolepsy, decreased thickness of the substantia nigra was found and in six of them degenerative lesions in the pontine substantia nigra were also noticed.ConclusionsThe significance of these changes remains unclear. No data have been published until now concerning the presence of any brain lesions in patients with familial narcolepsy.     

Two cases of HLA-DR2-negative hypersomnia manifesting sleep-onset rapid eye movement periods in the multiple sleep latency test

We encountered two cases expressing excessive daytime sleepiness (EDS) and manifesting two or more sleep-onset rapid eye movement (REM) periods in the multiple sleep latency test. Unbearable daytime sleepiness occurred abruptly, which usually led to short-lasting naps, after which the patients felt refreshed. The EDS was successfully reduced by treatment with methylphenidate. In spite of these features similar to narcolepsy, these cases of REM hypersomnia did not present cataplexy or other auxiliary symptoms of narcolepsy, and, furthermore, the class-II human leukocyte antigen DR2 appeared to be negative.     

Hypocretin Ligand Deficiency in Narcolepsy: Recent Basic and Clinical Insights

Narcolepsy is a chronic sleep disorder characterized by excessive daytime sleepiness, cataplexy, hypnagogic hallucinations, and sleep paralysis. Both sporadic and familial forms exist in humans. Recently, the major pathophysiology of human narcolepsy was indicated, based on discovery, through animal study, of narcolepsy genes involved in the pathology of hypocretin/orexin ligand and its receptor. Hypocretin ligand deficiency is found in most patients with narcolepsy with cataplexy. This deficiency likely is the result of postnatal cell death of hypocretin neurons, and involvement of autoimmune mechanisms is suggested. Hypocretin deficiency also is found in symptomatic narcolepsy and excessive daytime sleepiness with neurologic conditions, including immune-mediated neurologic disorders. These findings have significant clinical relevance and promote understanding of hypocretin cell death mechanisms. Already, discoveries in humans have led to a new diagnostic test for narcolepsy. Currently, hypocretin replacement therapy has emerged as a promising therapeutic option, and experiments using gene therapy and cell transplantation are in progress.     

Clinical and polysomnographic features in DQB1*0602 positive and negative narcolepsy patients: results from the modafinil clinical trial

Background: Narcolepsy, a neurological disorder characterized by excessive daytime sleepiness and abnormal REM sleep, is known to be tightly associated with the human leukocyte antigen (HLA) DQB1*0602.Methods: In this study, baseline data collected for a large clinical trial involving 504 narcolepsy patients were used to compare clinical and polysomnographic features of narcolepsy patients with and without HLA-DQB1*0602. Comparisons were adjusted for possible confounding factors and linear regression modeling was used to extract the best predictors for DQB1*0602 positivity.Results: As previously reported, cataplexy was the best clinical predictor for DQB1*0602 positivity. At the polysomnographic level, subjects with DQB1*0602 were found to have a significantly more disrupted nocturnal sleep, a much shorter nocturnal rapid eye movement (REM) sleep latency and more multiple sleep latency test abnormalities (increased number of sleep onset REM periods and decreased mean sleep latency). We also found that subjects with DQB1*0602 had a much higher incidence of periodic limb movements during sleep, confirming the notion that this symptom is genuinely associated with the narcolepsy phenotype.Conclusions: These results support the notion that HLA-DQB1*0602-positive narcolepsy patients are more etiologically homogenous than HLA-DQB1*0602-negative narcoleptic patients.     

Obstructive sleep apnea in narcolepsy

Study objectivesNarcolepsy and obstructive sleep apnea syndrome (OSAS) are two conditions associated with excessive daytime sleepiness (EDS). They may coexist in the same patient but the frequency of this association and its clinical significance is unknown. The presence of obstructive sleep apnea (OSA) in a narcoleptic patient may interfere with the diagnosis of narcolepsy. The aim of the study was to determine the prevalence of OSA in narcolepsy.Design and settingUniversity hospital sleep clinic series of narcoleptic patients diagnosed with nocturnal polysomnography and multiple sleep latency test. Patients were systematically interviewed evaluating narcoleptic and OSAS features and their response to continuous positive airway pressure (CPAP) treatment when applied.PatientsOne hundred and thirty-three patients with narcolepsy.ResultsThirty-three patients (24.8%) had an apnea–hypopnea index greater than 10 with a mean index of 28.5 ± 15.7. Ten of them were initially diagnosed only with OSAS and the diagnosis of narcolepsy was delayed 6.1 ± 7.8 years until being evaluated in our center for residual EDS after CPAP therapy. In the remaining 23 patients, narcolepsy and OSA were diagnosed simultaneously. Cataplexy occurred with similar frequency in both groups. EDS did not improve in 11 of the 14 patients who were treated with CPAP. The presence of OSA was associated with male gender, older age and higher body mass index.ConclusionsOSA occurs frequently in narcolepsy and may delay the diagnosis of narcolepsy by several years and interfere with its proper management. In patients with OSA, cataplexy should be actively looked for to exclude the presence of narcolepsy. Treatment with CPAP does not usually improve EDS in narcoleptics with OSA.     

Characterization of symptoms of sleep disorders in children with headache

To investigate the prevalence of sleep disorders and their symptoms in children with headaches, 64 patients in the outpatient clinics of the University of Chicago Department of Pediatric Neurology were interviewed. Investigated disorders included excessive daytime sleepiness, narcolepsy, insomnia, sleep apnea, restlessness, and parasomnias. Unlike previous studies, subjects were compared with matched control patients by age and sex. Both headache and nonheadache groups completed a 111-item questionnaire detailing sleep symptoms and behaviors. It was found that children with headaches have a significantly higher prevalence of excessive daytime sleepiness, narcolepsy, and insomnia than children without headaches (P < 0.005), which is consistent with prior literature. A similar result was obtained in examining only migraines. However, we did not find a significantly higher prevalence of symptoms of sleep apnea, restlessness, and parasomnias, which contradicts previous literature. Also, the effect of medications taken by headache patients as a confounding factor was insignificant. Overall, pediatricians may find it beneficial to ask about daytime sleepiness, narcolepsy, and insomnia when treating a headache patient.     

Diet therapy for narcolepsy

The effects of a low-carbohydrate, ketogenic diet (LCKD) on sleepiness and other narcolepsy symptoms were studied. Nine patients with narcolepsy were asked to adhere to the Atkins' diet plan, and their symptoms were assessed using the Narcolepsy Symptom Status Questionnaire (NSSQ). The NSSQ-Total score decreased by 18% from 161.9 to 133.5 (p = 0.0019) over 8 weeks. Patients with narcolepsy experienced modest improvements in daytime sleepiness on an LCKD.     

Narcolepsy in the Pediatric Population

Narcolepsy is characterized by excessive daytime sleepiness, with or without cataplexy. Associated features include sleep paralysis, hypnagogic or hypnopompic hallucinations, and disturbed nocturnal sleep. Narcolepsy is strongly associated with the HLA DQB1*0602 allele, and its symptoms stem from destruction of hypocretin-secreting neurons in the hypothalamus. Recently identified autoantibodies to Tribbles homologue 2 in some patients, as well as cases associated with H1N1 vaccination, support an autoimmune mechanism. There are many challenges in diagnosing and treating pediatric narcolepsy. Caution must also be used in interpreting polysomnography and multiple sleep latency test results in children. HLA testing is nonspecific, and no commercial test exists to measure cerebrospinal fluid hypocretin levels. Neuroimaging has not yet proven useful in primary narcolepsy. Treatment of sleepiness and cataplexy in children requires extrapolating from adult studies. Hopefully, further insights into the pathophysiology of narcolepsy will allow for new therapeutics to manage the symptoms and modify the course of the disease.     

Normal levels of cerebrospinal fluid hypocretin-1 and daytime sleepiness during attacks of relapsing-remitting multiple sclerosis and monosymptomatic optic neuritis

There is emerging evidence that multiple sclerosis (MS), the hypothalamic sleep-wake regulating neuropeptide hypocretin-1 (hcrt-1) and the sleep disorder narcolepsy may be connected. Thus, the major pathophysiological component of narcolepsy is lack of hcrt-1. Dysfunction of the hypocretin system has been reported in MS case reports with attacks of hypothalamic lesions, undetectable cerebrospinal fluid (CSF) hcrt-1 and hypersomnia, but not found during remission in small samples. Finally, daytime sleepiness, the major symptom of narcolepsy, is reported in several MS populations, and there are case reports of co-existent narcolepsy and MS. However, it is unknown whether hcrt-1 and daytime sleepiness generally change during MS attacks. We therefore analyzed whether daytime sleepiness (using the Epworth Sleepiness Scale (ESS)) and CSF hcrt-1 levels differed between MS attack and remission, in 48 consecutively referred patients with relapsing-remitting MS (RRMS) or monosymptomatic optic neuritis (MON). Twenty-seven patients were in attack and 21 in remission. ESS was normal both during attacks (5.4 +/- 3.0) and remission (5.8 +/- 2.6), and mean CSF hcrt-1 was normal (456 +/- 41 pg/ml). No statistically significant differences were found between attack and remission. MRI scans revealed no hypothalamic lesions. The results show that the hypocretin system is intact and sleepiness is not typical in RRMS and MON without hypothalamic lesions on MRI.     

Low cerebrospinal fluid hypocretin levels found in familial narcolepsy

OBJECTIVE: This report describes abnormal hypocretin neurotransmission in a case of familial narcolepsy. BACKGROUND: Narcolepsy is a chronic, often-disabling central nervous system disorder characterized by excessive daytime sleepiness and abnormal rapid eye movement (REM) sleep features including cataplexy, a loss of muscle tone triggered by emotion. The cause of human narcolepsy is unknown. Several familial cases have been described, but most cases are sporadic (95%). An abnormality of hypocretin neurotransmission has been found in a majority of sporadic cases. METHODS: Hypocretin-1 levels were measured in the cerebrospinal fluid of the narcoleptic proband of a family with several affected members. RESULTS: The proband was found to have a hypocretin-1 deficiency. CONCLUSION: Abnormal hypocretin neurotransmission is found in familial, as well as sporadic, narcolepsy.     

Hypocretin-1 CSF levels in anti-Ma2 associated encephalitis

Idiopathic narcolepsy is associated with deficient hypocretin transmission. Narcoleptic symptoms have recently been described in paraneoplastic encephalitis with anti-Ma2 antibodies. The authors measured CSF hypocretin-1 levels in six patients with anti-Ma2 encephalitis, and screened for anti-Ma antibodies in patients with idiopathic narcolepsy. Anti-Ma autoantibodies were not detected in patients with idiopathic narcolepsy. Four patients with anti-Ma2 encephalitis had excessive daytime sleepiness; hypocretin-1 was not detectable in their cerebrospinal fluid, suggesting an immune-mediated hypocretin dysfunction.     

Excessive fragmentary myoclonus in NREM sleep: a report of 38 cases

We report 38 consecutive patients referred to a sleep disorder clinic who on diagnostic polysomnography showed excessive amounts of brief fragmentary myoclonus throughout all stages of NREM sleep. Almost all patients were male despite a reasonably equal sex distribution of referral. The phenomenon was found associated with sleep-related respiratory problems, periodic movements in sleep (PMS), narcolepsy, intermittent hypersomnia and (rarely) insomnia. It also occurred associated with excessive daytime sleepiness (EDS) as an isolated polysomnographic finding apart from some degree of sleep fragmentation.     

Narcolepsy in children: a single-center clinical experience

Although the initial manifestations of narcolepsy in children may differ from those with adult onset, hypersomnia remains the most common presenting sign. This study aimed to (1) describe the clinical and polysomnographic features, and treatment outcomes, of a group of children with narcolepsy, and (2) describe other sleep disorders to be considered in the differential diagnosis of hypersomnia and which may coexist with narcolepsy. A retrospective review of 125 children referred in 1 year for hypersomnia revealed 20 patients (16%) with narcolepsy. Of these, only 15% exhibited cataplexy, 10% experienced hallucinations, and none manifested sleep paralysis. Eighty-five percent of children with narcolepsy had sleep-disordered breathing on polysomnography. Body mass indices of these children were higher than for healthy, age-matched controls subjects. Other polysomnography findings included periodic limb movements of sleep (25%) and parasomnias (5%). The multiple sleep latency test revealed a mean sleep latency of 6.14 minutes, with sleep-onset rapid eye movement periods (median, 2/5 naps). Treatment with modafinil and sodium oxybate provided optimal control of daytime sleepiness. Physicians should routinely screen for hypersomnia in children by obtaining a detailed history and, in appropriate situations, ordering polysomnographic testing to rule out narcolepsy and other causes of hypersomnia.     

Symptoms and occurrences of narcolepsy: a retrospective study of 162 patients during a 10-year period in Eastern China

ObjectiveOur study was designed to assess symptomatology and occurrences of narcolepsy in Eastern China between 2003 and 2012. Herein we report the substantial changes in the occurrence and clinical features of narcolepsy over the last decade in China.MethodsWe performed a retrospective analysis of 162 Han Chinese patients with narcolepsy at Changzheng Hospital, Shanghai, China. Clinical histories and precipitating factors were recorded, in addition to narcolepsy and H1N1 winter flu pandemic (pH1N1) occurrences at Changzheng Hospital. The occurrences also were compared between the Changzheng Hospital and the People’s Hospital, Beijing, China.ResultsIn our sample, narcolepsy occurred 1.73 times more frequently in men than in women. Most of the participants were children, which peaked to 91% in 2010. Excessive daytime sleepiness (EDS), disrupted nocturnal sleep, cataplexy, and weight gain were the four major symptoms. We found that 40% of patients had identifiable precipitating factors. The occurrence of narcolepsy in 2010 showed an approximate three-fold difference from the baseline levels at the Changzheng Hospital, which showed positive relationships with occurrences of pH1N1 in Shanghai and the occurrence of narcolepsy at the People’s Hospital.ConclusionsOur findings show the interactive effects of geography and H1N1 disease in relation to narcolepsy in Han Chinese populations, and strengthen the theoretic hypothesis that immune and mental factors facilitate the onset of narcolepsy.     

Hypocretin (orexin) deficiency predicts severe objective excessive daytime sleepiness in narcolepsy with cataplexy

Cerebrospinal fluid (CSF) hypocretin-1 deficiency is associated with definite ("clear cut") cataplexy in patients with narcolepsy. The relationship between CSF hypocretin-1 levels and other narcoleptic symptoms (including excessive daytime sleepiness, EDS) is not properly understood. In a consecutive series of 18 subjects with narcolepsy and definite cataplexy, patients with undetectable CSF hypocretin-1 (n = 12) were found to have significantly lower mean sleep latencies (p = 0.045) and a higher frequency of sleep onset REM periods (SOREMPs, p = 0.025) on multiple sleep latency test than patients (n = 6) with detectable levels. Conversely, Epworth sleepiness scale scores, the frequency of hallucinations/sleep paralysis, and the frequency and severity of cataplexy were similar in both groups. These results suggest that hypocretin deficiency identifies a homogenous group of patients with narcolepsy characterised by the presence of definite cataplexy, severe EDS, and frequent SOREMPs.