Narcolepsy with cataplexy in early childhood

Intravenous Immunoglobulin Therapy in Pediatric Narcolepsy: A Nonrandomized, Open-Label, Controlled, Longitudinal Observational Study

STUDY OBJECTIVES

Previous case reports of intravenous immunoglobulins (IVIg) in pediatric narcolepsy have shown contradictory results.

METHODS

This was a nonrandomized, open-label, controlled, longitudinal observational study of IVIg use in pediatric narcolepsy with retrospective data collection from medical files obtained from a single pediatric national reference center for the treatment of narcolepsy in France. Of 56 consecutively referred patients with narcolepsy, 24 received IVIg (3 infusions administered at 1-mo intervals) in addition to standard care (psychostimulants and/or anticataplectic agents), and 32 continued on standard care alone (controls).

RESULTS

For two patients in each group, medical files were unavailable. Of the 22 IVIg patients, all had cerebrospinal fluid (CSF) hypocretin ≤ 110 pg/mL and were HLA-DQB1*06:02 positive. Of the 30 control patients, 29 were HLA-DQB1*06:02 positive and of those with available CSF measurements, all 12 had hypocretin ≤ 110 pg/mL. Compared with control patients, IVIg patients had shorter disease duration, shorter latency to sleep onset, and more had received H1N1 vaccination. Mean (standard deviation) follow-up length was 2.4 (1.1) y in the IVIg group and 3.9 (1.7) y in controls. In multivariate-adjusted linear mixed-effects analyses of change from baseline in Ullanlinna Narcolepsy Scale (UNS) scores, high baseline UNS, but not IVIg treatment, was associated with a reduction in narcolepsy symptoms. On time-to-event analysis, among patients with high baseline UNS scores, control patients achieved a UNS score < 14 (indicating remission) less rapidly than IVIg patients (adjusted hazard ratio 0.18; 95% confidence interval: 95% confidence interval: 0.03, 0.95; p = 0.043). Shorter or longer disease duration did not influence treatment response in any analysis.

CONCLUSIONS

Overall, narcolepsy symptoms were not significantly reduced by IVIg. However, in patients with high baseline symptoms, a subset of IVIg-treated patients achieved remission more rapidly than control patients.

COMMENTARY

A commentary on this article appears in this issue on page 363.

Attention-Deficit/Hyperactivity Disorder (ADHD) Symptoms in Pediatric Narcolepsy: A Cross-Sectional Study

STUDY OBJECTIVES

To evaluate the frequency, severity, and associations of symptoms of attention-deficit/hyperactivity disorder (ADHD) in children with narcolepsy with and without cataplexy.

DESIGN

Cross-sectional survey.

SETTINGS

Four French national reference centers for narcolepsy.

PATIENTS

One hundred eight consecutively referred children aged younger than 18 y with narcolepsy, with (NwC, n = 86) or without cataplexy (NwoC, n = 22), and 67 healthy controls.

INTERVENTIONS

The participants, their families, and sleep specialists completed a structured interview and questionnaires about sleep, daytime sleepiness, fatigue, and ADHD symptoms (ADHD-rating scale based upon Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision [DSM-IV-TR] symptoms), and use of psychostimulants for the treatment of narcolepsy (administered in 68.2%). Polysomnographic measures were collected.

MEASUREMENTS AND RESULTS

Clinically significant levels of ADHD symptoms were found in 4.8% of controls compared with 35.3% in patients with NwoC (P < 0.001) and 19.7% in patients with NwC (P < 0.01). Total ADHD scores were 6.4 (95% confidence interval [CI]: 4.5, 9.0) in controls compared with 14.2 (95% CI: 10.6, 18.9; P < 0.001), in patients with NwoC and 12.2 (95% CI: 9.8, 15.3; P < 0.01) in patients with NwC; subscores of inattention and hyperactivity/impulsivity were also significantly higher in both narcolepsy groups compared with controls. No difference was found between the NwC and NwoC groups for any ADHD measure. ADHD symptom severity was associated with increased levels of sleepiness, fatigue, and insomnia. Compared with the 34 untreated patients, the 73 patients treated with psychostimulants (modafinil in 91%) showed a trend toward lower narcolepsy symptoms but not lower ADHD symptoms.

CONCLUSIONS

Pediatric patients with narcolepsy have high levels of treatment-resistant attention-deficit/hyperactivity disorder (ADHD) symptoms. The optimal treatment for ADHD symptoms in these patients warrants further evaluation in longitudinal intervention studies.

The impact of gender on timeliness of narcolepsy diagnosis

STUDY OBJECTIVES

To examine the impact of gender in narcoleptic patients on timeliness of diagnosis, symptomology, and health and lifestyle impairment.

METHODS

This is a cross-sectional study of 109 consecutive patients (68 women) with newly diagnosed narcolepsy with and without cataplexy, from a University sleep disorders center. Consecutive patients were administered an 8-page questionnaire at the time of their diagnosis regarding sleep habits, medications, and medical conditions, lifestyle impairments, as well as details regarding narcolepsy-related symptoms.

RESULTS

Men and women presented with remarkably similar narcolepsy related symptoms, yet women were more likely to be delayed in diagnosis; 85% of men were likely to be diagnosed by 16 years after symptom onset, compared to 28 years in women. More women were likely to remain undiagnosed at any given time point after symptom onset (hazard ratio for diagnosis of men compared to women 1.53; 95% CI 1.01-2.32; p = 0.04). Men and women reported similar degree of subjective sleepiness as measured by the Epworth Sleepiness Scale (mean 16.2 ± 4.5; p = 0.18), though women demonstrated significantly more severe objective sleepiness on multiple sleep latency testing (MSLT) (mean sleep latency in women = 5.4 min (± 4.1), in men 7.4 min (± 3.5); p = 0.03). Despite being more objectively sleepy, women were less likely to report lifestyle impairments in the areas of personal relationships (71% men, 44% women, p = 0.01) and physical activity (36% men, 16% women, p = 0.02), but were also more likely to self-medicate with caffeine (63.4% men, 82.4% women; p = 0.03).

CONCLUSIONS

Narcolepsy impacts men and women's health and lifestyle differently, and may cause delays diagnosis for women.

Narcolepsy and other hypersomnias in children

PURPOSE OF REVIEW

We provide an update on the pathogenesis, diagnosis, assessment (clinical and laboratory), and treatment options for children with narcolepsy and other hypersomnias of central origin in order to raise awareness of these diseases and to highlight the clinical findings that should make the pediatrician suspect the diagnosis.

RECENT FINDINGS

Narcolepsy is a chronic rapid eye movement sleep disorder. Accumulating evidence indicates that signs of narcolepsy may start during childhood. Recent data suggest that a deficiency in the hypothalamic orexin/hypocretin system underlies the pathogenesis of narcolepsy with cataplexy. Confirmatory tests such as polysomnography, multiple sleep latency test, and actigraphy, along with referral to a sleep physician, maybe necessary in appropriate cases. Laboratory tests such as human leukocyte antigen typing and cerebrospinal fluid hypocretin-1 analysis are useful as adjuncts. Modafinil is now considered the first-line treatment for excessive sleepiness in adult patients with narcolepsy. Sodium oxybate is currently approved by the Food and Drug Administration for the treatment of narcolepsy with cataplexy in patients aged more than 16 years.

SUMMARY

Awareness of the extent of hypersomnia in children will allow physicians to effectively screen every child; once identified, further assessment should be performed in order to diagnose and treat the underlying cause. Better understanding of pathogenesis, availability of newer therapies with different mechanism of effect, and appropriately designed randomized clinical trials should allow improved management of children with narcolepsy.