Altered slow-wave sleep activity in children with rapid-onset obesity with hypothalamic dysregulation, hypoventilation, and autonomic dysregulation syndrome

Case Report: Considerations of nocturnal ventilator support in ROHHAD syndrome in chronic care of childhood central hypoventilation with hypothalamus dysfunction

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) is a rare life-threatening disorder that can occur during childhood. All children with ROHHAD develop alveolar hypoventilation during wakefulness and sleep. The key treatment for these patients is the optimization of oxygenation and ventilation. Here, we report the case of a 5-year-old girl with suspected ROHHAD, with rapid weight gain, breathing cessation, decreased height, hypoventilation, central hypothyroidism, hyperprolactinemia, and absolute deficiency of growth hormone, and negative PHOX2B sequencing results. The presentation met the diagnostic criteria for ROHHAD syndrome. During the 5-year follow-up, she presented with progressive deterioration of the function of the hypothalamus and respiratory center, hypoxemia (PO₂ < 60 mmHg), and hypercapnia [transcutaneous carbon dioxide (TcPCO₂) > 70 mmHg] during the first two cycles of N3 sleep with a poor response to ventilatory support. Early diagnosis and application of non-invasive positive pressure ventilation during sleep can improve the quality of life and outcomes of patients with ROHHAD, and polysomnography and TcPCO₂ should be repeated every 3-6 months to follow the progress and regulate ventilator support. Multidisciplinary care is crucial for the successful management of these patients.

Obstructive sleep apnea and metabolic disorders in morbidly obese adolescents

BACKGROUND

Little known about the prevalence of obstructive sleep apnea (OSA) in morbid obese adolescents and the association between OSA and comorbid factors.

AIM

To examine the association between apnea-hypopnea index (AHI, a measure for OSA severity) and metabolic morbidity among morbidly obese adolescents.

METHODS

We performed a population-based retrospective cohort study by reviewing sleep study, metabolic indices, and comorbidity-related data of a cohort (n = 106) of adolescents referred to a bariatric surgery clinic. We compared subjects with moderate/severe OSA (AHI ≥ 5) versus no/mild OSA (AHI < 5) OSA and three groups of subjects with increasing body mass index (BMI) concerning sleep-study and metabolic indices using univariate analyses. To assess the link between AHI and ferritin levels a multivariate linear regression (adjusted for BMI and mean cell volume) was preformed.

RESULTS

A total of 71 patients met the inclusion criteria. Subjects with moderate/severe OSA (n = 32, 45%) had higher BMI, cholesterol, cholesterol/high-density lipoprotein (HDL) ratio, hemoglobin A1c, and serum ferritin levels (p < .05). AHI significantly increased across BMI strata (p = .02). Multivariate linear regression indicated that moderate/severe OSA was associated with higher levels of ferritin, unstandardized β = 49.1 (nIU/ml) (p = .025).

CONCLUSIONS

Morbidly obese adolescents with moderate/severe OSA versus no/mild OSA have a higher risk for metabolic complications. Therefore, OSA management should be considered in adolescents with morbid obesity, in addition to weight loss.

Sleep disorders and the hypothalamus

As early as the 1920s, pathological studies of encephalitis lethargica allowed Von Economo to correctly identify hypothalamic damage as crucial for the profound associated sleep-related symptoms that helped define the condition. Only over the last 3 decades, however, has the key role of the hypothalamus in sleep-wake regulation become increasingly recognized. As a consequence, a close relation between abnormal sleep symptomatology and hypothalamic pathology is now widely accepted for a variety of medical disorders. Narcolepsy is discussed in some detail as the cardinal primary sleep disorder that is caused directly and specifically by hypothalamic pathology, most notably destruction of hypocretin (orexin)-containing neurons. Thereafter, various conditions are described that most likely result from hypothalamic damage, in part at least, producing a clinical picture resembling (symptomatic) narcolepsy. Kleine-Levin syndrome is a rare primary sleep disorder with intermittent symptoms, highly suggestive of hypothalamic involvement but probably reflecting a wider pathophysiology. ROHHAD (rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation) and Prader-Willi syndrome are also covered as hypothalamic syndromes with prominent sleep-related symptoms. Finally, sleep issues in several endocrine disorders are briefly discussed.