Late onset central hypoventilation syndrome

Rapid-onset obesity, hypothalamic dysfunction, hypoventilation, and autonomic dysregulation in Saudi Arabia

Rapid-onset obesity, hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) is a rare disease, but could be fatal if not diagnosed early. It mimics many other diseases and it may take few years after the onset of rapid obesity to have the other clinical features. Therefore, any patient with rapid-onset obesity after the age of 2 years should have high index of suspicion and long term follow up. We report a case of ROHHAD in Saudi Arabia and we highlight the clinical features and the importance of early diagnosis and management.

[Spanish patients with central hypoventilation syndrome included in the European Registry. The 2015 data]

INTRODUCTION

Congenital Central Hypoventilation Syndrome (CCHS) is a very rare genetic disease. In 2012 the European Central Hypoventilation Syndrome (EuCHS) Consortium created an online patient registry in order to improve care.

AIM

To determine the characteristics and outcomes of Spanish patients with CCHS, and detect clinical areas for improvement.

MATERIALS AND METHOD

An assessment was made on the data from Spanish patients in the European Registry, updated on December 2015.

RESULTS

The Registry contained 38 patients, born between 1987 and 2013, in 18 hospitals. Thirteen (34.2%) were older than 18 years. Three patients had died. Genetic analysis identified PHOX2B mutations in 32 (86.5%) out of 37 patients assessed. The 20/25, 20/26 and 20/27 polyalanine repeat mutations (PARMs) represented 84.3% of all mutations. Longer PARMs had more, as well as more severe, autonomic dysfunctions. Eye diseases were present in 47%, with 16% having Hirschsprung disease, 13% with hypoglycaemia, and 5% with tumours. Thirty patients (79%) required ventilation from the neonatal period onwards, and 8 (21%) later on in life (late onset/presentation). Eight children (21%) were using mask ventilation at the first home discharge. Five of them were infants with neonatal onset, two of them, both having a severe mutation, were switched to tracheostomy after cardiorespiratory arrest at home. Approximately one-third (34.3%) of patients were de-cannulated and switched to mask ventilation at a mean age of 13.7 years. Educational reinforcement was required in 29.4% of children attending school.

CONCLUSION

The implementation of the EuCHS Registry in Spain has identified some relevant issues for optimising healthcare, such as the importance of genetic study for diagnosis and assessment of severity, the high frequency of eye disease and educational reinforcement, as well as some limitations in ventilatory techniques.

Rapid-onset obesity with hypothalamic dysregulation, hypoventilation, and autonomic dysregulation (ROHHAD syndrome): A case report and literature review

INTRODUCTION

ROHHAD syndrome (rapid-onset obesity with hypothalamic dysregulation, hypoventilation, and autonomic dysregulation) is a rare and complex disease, presenting in previously healthy children at the age of 2-4 years. Up to 40% of cases are associated with neural crest tumours.

DEVELOPMENT

We present the case of a 2-year-old girl with symptoms of rapidly progressing obesity, who a few months later developed hypothalamic dysfunction with severe electrolyte imbalance, behaviour disorder, hypoventilation, and severe autonomic dysregulation, among other symptoms. Although the pathophysiology of this syndrome remains unclear, an autoimmune hypothesis has been proposed for ROHHAD. Therefore, after obtaining a limited response to intravenous immunoglobulins, we decided to test the response to a high dose cyclophosphamide (low dose was not effective either). Unfortunately our patient experienced many severe complications (among them central pontine myelinolysis, from which the patient recovered, and failure to wean from the ventilator requiring tracheostomy and long term ventilation) that required a prolonged ICU stay. Although her behaviour improved, our patient unfortunately died suddenly at home at the age of 5 due to respiratory pathology.

CONCLUSIONS

ROHHAD syndrome is a rare and little-known disease which requires a multidisciplinary approach because it involves complex symptoms and multiple organ system involvement. Alveolar hypoventilation should be identified early and appropriate treatment should be started promptly for the best possible outcome. Immunomodulatory treatment with immunoglobulins, cyclophosphamide, or rituximab has previously resulted in symptom improvement in some cases. Because of the low incidence of the syndrome, multi-centre studies must be carried out in order to gather more accurate information about ROHHAD pathophysiology and design an appropriate therapeutic approach.

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD): Response to ventilatory challenges

Hypoventilation is a defining feature of Rapid-onset Obesity with Hypothalamic dysfunction, Hypoventilation and Autonomic Dysregulation (ROHHAD), a rare respiratory and autonomic disorder. This chronic hypoventilation has been explained as the result of dysfunctional chemosensory control circuits, possibly affecting peripheral afferent input, central integration, or efferent motor control. However, chemosensory function has never been quantified in a cohort of ROHHAD patients. Therefore, the purpose of this study was to assess the response to awake ventilatory challenge testing in children and adolescents with ROHHAD. The ventilatory, cardiovascular and cerebrovascular responses in 25 distinct comprehensive physiological recordings from seven unique ROHHAD patients to three different gas mixtures were analyzed at breath-to-breath and beat-to-beat resolution as absolute measures, as change from baseline, or with derived metrics. Physiologic measures were recorded during a 3-min baseline period of room air, a 3-min gas exposure (of 100% O2; 95% O2, 5% CO2; or 14% O2, 7% CO2 balanced with N2), and a 3-min recovery period. An additional hypoxic challenge was conducted which consisted of either five or seven tidal breaths of 100% N2. While ROHHAD cases showed a diminished VT and inspiratory drive response to hypoxic hypercapnia and absent behavioral awareness of the physiologic compromise, most ventilatory, cardiovascular, and cerebrovascular measures were similar to those of previously published controls using an identical protocol, suggesting a mild chemosensory deficit. Nonetheless, the high mortality rate, comorbidity and physiological fragility of patients with ROHHAD demand continued clinical vigilance.

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation and autonomic dysregulation (ROHHAD): a case with additional features and review of the literature

A rare syndrome of rapid-onset obesity with hypothalamic dysfunction, hypoventilation and autonomic dysregulation (ROHHAD) has been recently described. We report the first patient with this syndrome in Southeast Asia and review reported cases to date. Our patient was good health with normal development until the age of 2. He then developed hyperphagic obesity, hypersomnolence, seizures, alveolar hypoventilation, central hypothyroidism, sodium and water dysregulation, gastrointestinal dysmotility, strabismus, disordered temperature and irregular heart rate, altered sweating, delayed puberty, mental retardation and recurrent respiratory tract infections. The cardiomyopathy with heart failure and abnormal cerebral spinal fluid (CSF) neurotransmitter analysis present in our patient have not been reported previously. Tumours of the sympathetic nervous system are known to be associated with this syndrome but had not been found in our patient at the time of reporting. We highlight the difficulty of achieving the diagnosis of ROHHAD syndrome and its overlap with other well-established disease entities. The mortality and morbidity resulting from the high incidence of cardiorespiratory arrest may be prevented by early ventilatory support.

Carbon dioxide chemoreception and hypoventilation syndromes with autonomic dysregulation

Respiratory and autonomic disorders of infancy, childhood, and adulthood are a group of disorders that have varying presentation, combined with a range of severity of respiratory control and autonomic nervous system dysfunction. Within this group, congenital central hypoventilation syndrome and rapid onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation, exhibit the greatest respiratory control deficits, requiring supported ventilation as a mainstay of care. The discovery of the key role of the paired-like homeobox 2B gene in autonomic nervous system development, along with the identification of paired-like homeobox 2B gene mutations causing congenital central hypoventilation syndrome, has led to a fruitful dialog between basic scientists and physician-scientists, producing an explosion of knowledge regarding genotype-phenotype correlations in this disorder, as well as important animal models of chemosensory regulation deficit. Though the etiology of rapid onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation is still to be determined, recent studies have begun to carefully delineate the phenotype, suggesting that it too may provide fertile ground for research that both advances our knowledge and improves patient care.

Endocrine manifestations of the rapid-onset obesity with hypoventilation, hypothalamic, autonomic dysregulation, and neural tumor syndrome in childhood

CONTEXT

Rapid-onset obesity with hypoventilation, hypothalamic, autonomic dysregulation, and neural tumor (ROHHADNET) is a newly described syndrome that can cause cardiorespiratory arrests and death. It mimics several endocrine disorders or genetic obesity syndromes during early childhood and is associated with various forms of hypothalamic-pituitary endocrine dysfunctions that have not yet been fully investigated.

OBJECTIVE

The current report aspires to facilitate the earlier recognition and appropriate treatment of the ROHHADNET syndrome when children present with various endocrine manifestations, such as early obesity, growth failure, pseudo-Cushing's syndrome, glucocorticoid insufficiency, congenital hypopituitarism, or adrenal tumors. A more widespread knowledge of the syndrome will help characterize its molecular origin.

DESIGN

Endocrine studies were performed in six patients admitted for seemingly common early-onset obesity associated with growth failure in five of them. The six patients later showed distinctive features of the ROHHADNET syndrome.

RESULTS

Abnormalities of the pituitary adrenal axis ranged from a true Cushing-like profile (one of six), to glucocorticoid deficiency with normal ACTH (two of six). Complete GH deficiency with low IGF-I was observed in four of six, hypogonadotropic hypogonadism in four of six, hyperprolactinemia in six of six, and various degrees of TSH/T(4) abnormalities in five of five patients. All had increased natremia without diabetes insipidus. Five children had unilateral macroscopic adrenal ganglioneuroma. Two patients died at 8.5 and 12 yr of age.

CONCLUSIONS

Various hypothalamic-pituitary endocrine dysfunctions are associated with ROHHADNET, carrying a risk of misdiagnosis until other elements of the syndrome make it more easily recognizable. Given its severity, ROHHADNET syndrome should be considered in all cases of isolated, rapid, and early obesity.

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation presenting in childhood

OBJECTIVE

The goal was to characterize the phenotype and potential candidate genes responsible for the syndrome of late-onset central hypoventilation with hypothalamic dysfunction.

METHODS

Individuals with late-onset central hypoventilation with hypothalamic dysfunction who were referred to Rush University Medical Center for clinical or genetic assessment in the past 3 years were identified, and medical charts were reviewed to determine shared characteristics of the affected subjects. Blood was collected for genetic testing of candidate genes (PHOX2B, TRKB, and BDNF) and for high-resolution conventional G-banding, subtelomeric fluorescent in situ hybridization, and comparative genomic hybridization analysis. A subset of these children were studied in the Pediatric Respiratory Physiology Laboratory at Rush University Medical Center.

RESULTS

Twenty-three children with what we are now naming rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation were identified. Comprehensive medical charts and blood for genetic testing were available for 15 children; respiratory physiology studies were performed at Rush University Medical Center on 9 children. The most characteristic manifestations were the presentation of rapid-onset obesity in the first 10 years of life (median age at onset: 3 years), followed by hypothalamic dysfunction and then onset of symptoms of autonomic dysregulation (median age at onset: 3.6 years) with later onset of alveolar hypoventilation (median age at onset: 6.2 years). Testing of candidate genes (PHOX2B, TRKB, and BDNF) revealed no mutations or rare variants. High-resolution chromosome analysis, comparative genomic hybridization, and subtelomeric fluorescent in situ hybridization results were negative for the 2 patients selected for those analyses.

CONCLUSIONS

We provide a comprehensive description of the clinical spectrum of rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation in terms of timing and scope of symptoms, study of candidate genes, and screening for chromosomal deletions and duplications. Negative PHOX2B sequencing results demonstrate that this entity is distinct from congenital central hypoventilation syndrome.

Cardiovascular Abnormalities and Arrhythmias in Patients with Ondine's Curse (Congenital Central Hypoventilation) Syndrome

Patients with congenital central hypoventilation syndrome (CCHS) (Ondine's curse syndrome) have impaired autonomic control of ventilation with intact voluntary control of respiration. Autonomic dysfunction and cardiac abnormalities are common in CCHS. Bradyarrhythmias are life-threatening and often require pacemaker insertion. We presented a case of a patient with CCHS suffering from long sinus pauses requiring cardiac pacemaker insertion. Patients with CCHS are at risk for pulmonary hypertension and cor pulmonale secondary to chronic hypoxia. Diaphragmatic pacing has been beneficial in some patients with CCHS. In this article, we review concomitant cardiac abnormalities and the occurrence of bradyarrhythmias in patients with CCHS.

Tracheostomy and home ventilation in children

The last 30 years have brought a significant emphasis on home care for ventilator-dependent children. While the movement was driven by the desire to minimize healthcare costs, the advancements in medical knowledge and technology, and the change in the perception of a ventilator-dependent child have offered a fertile environment for the development of programs that support the chronic care of ventilator-dependent children at home (N. Engl. J. Med. 309(21) (1983) 1319; J. Pediatr. 106(5) (1985) 850; N. Engl. J. Med. 310(17) (1984) 1126; JAMA 258(23) (1987) 3398). In addition, the advances in medical and nursing care have led to the steady increase in the number of children with chronic respiratory failure and development of multi-disciplinary teams experienced and dedicated to the care of these children. Another trend that has also contributed to the rise in the number of pediatric patients using long-term mechanical ventilation is the parental expectation of long-term survival of their child. This parental expectation continues to grow as the effect of long-term mechanical ventilation on quality of life and longer survival becomes more evident. The primary indication for use of home mechanical ventilation is chronic respiratory failure (CRF) as indicated by hypoxemia and or hypercapnia. CRF is considered to be a condition persisting for greater than 1 month and requiring mechanical ventilation during part or all of the day to provide adequate gas exchange for the support of vital function (Chest 103(5) (1993) 1463).

[Central alveolar hypoventilation syndrome and cerebral venous thrombosis: fortuitous association?]

Central hypoventilation syndrome is defined as the failure of automatic control of breathing. Secondary central hypoventilation syndrome should distinguish from congenital central hypoventilation syndrome by brainstem abnormalities, place of respiratory control.

CASE REPORTS

We report two clinical cases characterized by late onset central hypoventilation syndrome (three years--six months, and five years old): in the first case the diagnosis was made after general anesthesia and the second one presented with acute nocturnal comatose state. Neuroradiologic investigations showed bilateral cerebral sinus veinous thrombosis without any brainstem lesions. Moreover these children had severe behavior disorders: psychomotor instability, alterations of social relations, language dysfunction, and neurocognitive deficit. This symptomatology seems independent from central hypoventilation syndrome and cerebral venous thrombosis.

CONCLUSION

Late onset central hypoventilation syndrome may be associated with cerebral venous thrombosis. Ischemia of central chemoreceptors or integration of their informations could be one of mechanism.

Late-onset central hypoventilation with hypothalamic dysfunction: a distinct clinical syndrome

Idiopathic central hypoventilation has occasionally been reported in previously well children after infancy. The relationship between this late-onset central hypoventilation syndrome (LO-CHS) and congenital central hypoventilation syndrome (CCHS) has not been established. Both CCHS and LO-CHS have been associated with neural crest tumors, such as ganglioneuroblastoma and ganglioneuroma, and they generally occur in the presence of a histologically normal central nervous system. At least 10 case reports of idiopathic LO-CHS featured evidence of hypothalamic dysfunction (HD), including hyperphagia, hypersomnolence, thermal dysregulation, emotional lability, and endocrinopathies. We report on a case of LO-CHS/HD successfully treated by nasal intermittent positive pressure ventilation (NIPPV). Despite the commonalties with CCHS, we propose that LO-CHS/HD is a distinct clinical syndrome. In addition to the markedly different age at presentation, features of hypothalamic dysfunction are not seen in CCHS. Review of the literature was undertaken to further clarify the full spectrum of the disease.

Congenital central hypoventilation syndrome: an update

Awareness of the existence of CCHS has led to increasingly frequent reports of such patients from all over the world. However, the exact pathophysiologic mechanisms underlying the clinical manifestations of this congenital disease entity remain unknown. For the respiratory physiologist, CCHS can be viewed as an experiment of nature that provides an important and unique window into central cardiorespiratory regulation. For the pediatrician, CCHS children represent an unique clinical challenge in coordinating the diagnostic and therapeutic procedures required to enhance the patients' quality of life.