Ondine curse and neurocristopathy

An unusual ophthalmologic finding in a patient with congenital central hypoventilation syndrome

INTRODUCTION

Congenital Central Hypoventilation Syndrome (CCHS) is a rare disease due to a severely impaired central control of breathing and dysfunction of the autonomic nervous system. Ophthalmologic abnormalities are common in patients with CCHS and include horizontal strabismus, pupil and iris abnormalities and ptosis. We report a unique case of CCHS in association with monocular elevation deficit (MED) in a boy diagnosed with CCHS at birth.

CASE DESCRIPTION

We report a case of a boy with a confirmed diagnosis of CCHS (complete sequencing of the paired-like homeobox 2b (PHOX2B) gene) after presenting little respiratory effort and cyanosis at birth. The ophthalmological examination shows an impaired elevation of the left eye, both in adduction and abduction, associated with mild and variable left ptosis. His mother has observed that the left eyelid elevates when the child feeds. A deviation in the primary gaze position or a chin-up position are not present. The funduscopic examination is normal. Given that deviation is limited to upgaze, the ptosis is mild and the patient's age, observation is decided.

CONCLUSIONS

Ophthalmologic abnormalities are common in patients with CCHS and include horizontal strabismus, pupil and iris abnormalities and ptosis. To the best of our knowledge, this is the first report of MED in association with CCHS. Further studies are needed to determine if an association between MED and CCHS exists or is just a casual finding in this case.

Congenital central hypoventilation syndrome: An overview of etiopathogenesis, associated pathologies, clinical presentation, and management

Congenital central hypoventilation syndrome (CCHS), known colloquially as Ondine's curse, is a rare disorder characterized by impaired autonomic control of breathing during sleep from the loss of vagal input and diminished sensitivity of CO₂ receptors in the medulla. CCHS correlates to the malformation of the neural crest located in the brainstem; this consequently affects the loss of sensitivity of CO₂ chemoreceptors, bringing about hypoventilation during sleep. The primary cause of CCHS is the mutation of the paired-like homeobox PHO2XB gene, found in 90% of the patients. This mutation not only affects breathing but also drives neurological abnormalities such as autonomic and neurocognitive dysfunction. Though typically congenital, there have been late-onset (i.e., acquired) cases reported. It is vital for physicians and clinicians to be able to diagnose CCHS due to its similar presentation to other syndromes and disorders, which may cause it to be misdiagnosed and may account for its deleterious effects. CCHS can lead to a constellation of symptoms, and consideration of diseases that present concomitantly with CCHS affords us a better understanding of the etiology of this illness. Although a rare syndrome, we aim to review the current literature to emphasize the pathogenesis, etiology, clinical presentation, symptoms, diagnosis, and current treatment methods of CCHS for clinicians to better identify and understand this condition.

Genetic diseases: congenital central hypoventilation, Rett, and Prader-Willi syndromes

The present review summarizes current knowledge on three rare genetic disorders of respiratory control, congenital central hypoventilation syndrome (CCHS), Rett syndrome (RTT), and Prader-Willi syndrome (PWS). CCHS is characterized by lack of ventilatory chemosensitivity caused by PHOX2B gene abnormalities consisting mainly of alanine expansions. RTT is associated with episodes of tachypneic and irregular breathing intermixed with breathholds and apneas and is caused by mutations in the X-linked MECP2 gene encoding methyl-CpG-binding protein. PWS manifests as sleep-disordered breathing with apneas and episodes of hypoventilation and is caused by the loss of a group of paternally inherited genes on chromosome 15. CCHS is the most specific disorder of respiratory control, whereas the breathing disorders in RTT and PWS are components of a more general developmental disorder. The main clinical features of these three disorders are reviewed with special emphasis on the associated brain abnormalities. In all three syndromes, disease-causing genetic defects have been identified, allowing the development of genetically engineered mouse models. New directions for future therapies based on these models or, in some cases, on clinical experience are delineated. Studies of CCHS, RTT, and PWS extend our knowledge of the molecular and cellular aspects of respiratory rhythm generation and suggest possible pharmacological approaches to respiratory control disorders. This knowledge is relevant for the clinical management of many respiratory disorders that are far more prevalent than the rare diseases discussed here.

Neurocristopathies presenting with neurologic abnormalities associated with Hirschsprung's disease

Neurocristopathies are a group of diverse disorders resulting from defective growth, differentiation, and migration of the neural crest cells. Hirschsprung's disease, namely aganglionic megacolon, is the consequence of defective migration of neural crest cells on to the colonic submucosa and is therefore considered a neurocristopathy. We report on four children in whom was diagnosed a neurocristopathy, associating Hirschsprung's disease with a wide spectrum of neurologic abnormalities. The patients included two children presenting the phenotypic features of the Goldberg-Shprintzen syndrome: distinct dysmorphic facial features, microcephaly, and mental retardation, along with agenesis of the corpus callosum and cortical malformations associated with intractable seizures in one child. The third newborn presented with the Haddad syndrome: short-segment Hirschsprung's disease associated with the congenital central hypoventilation syndrome requiring permanent artificial ventilation. In the fourth child, absence of the corpus callosum was associated with mild dysmorphic features, borderline cognitive abilities, and attention-deficit disorder. Therefore, awareness of a possible neurocristopathy associated with neurologic abnormalities should be taken into account in any patient newly diagnosed with Hirschsprung's disease to detect the abnormalities early and promptly manage them. A thorough neurologic examination and a developmental assessment, including magnetic resonance imaging of the brain and electroencephalography, should be performed for any child presenting with an aganglionic megacolon, especially those presenting with seizures, developmental delay, or even congenital hypoventilation.

[Neurochristopathy in the differential diagnosis of newborn's apnea: case report]

OBJECTIVE

to include neurocristopathy on the etiological workup of neonatal apneas and discuss the importance of polysomnography in this diagnosis.

METHOD

case report and critical review of the literature.

RESULTS

we report on a newborn that presented respiratory failure in the first hours of life associated to abdominal distention. Continuous ventilatory support was necessary, and the respiratory distress increased during sleep. After polysomnographic confirmation of hypoventilation the newborn was submitted to neuroradiolgic tests and colon byopsy, positive to Hirschsprung's disease.

CONCLUSION

Neurocristopathy syndrome can have many different clinical expression, and sometimes the syndrome can be misdiagnosed. Polysomnography confirms central hypoventilation. This diagnosis should be considered in the newborn's persistent apnea workup.

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.

Congenital central hypoventilation syndrome and Hirschsprung's disease

Five cases of the Hirschsprung's disease-congenital central hypoventilation syndrome (CCHS) association are presented and 41 other published cases reviewed. These children have a distinct pattern of associated features, an equal sex incidence, and a characteristic spectrum of disease severity which suggests that the condition is genetically distinct from other cases of Hirschsprung's disease. While approximately 1.5% of Hirschsprung's disease patients, and 10% of those with total colonic aganglionosis, will have CCHS, up to 50% of CCHS patients will have Hirschsprung's disease. Approximately 20% of CCHS/Hirschsprung patients will also have neuroblastoma or ganglioneuroma, usually multiple. Abnormalities of the eye and autonomic nervous system are also common. The ventilatory abnormality is usually evident on the first day of life. The aganglionosis is also severe, with more than half (59%) of the patients having aganglionosis extending into the small bowel.

Hirschsprung's disease associated with Ondine's curse: report of three cases and review of the literature

The cases of three full-term infant girls with both Hirschsprung's disease (HD) and Ondine's curse (OC) are presented, and the relevant literature is reviewed. All three patients required endotracheal intubation and assisted ventilation during the first 24 hours of life because of respiratory distress. The diagnosis of HD was subsequently established at age 13, 16, and 20 days, respectively. The aganglionic segment was confirmed to the rectum in one case, extended to the splenic flexure of the colon in the second case, and involved the terminal ileum in the third. The definitive treatment (endorectal pull-through) was completed successfully in all three patients, and the postoperative follow-up period was 3 to 34 months. All of them presently have tracheostomies and are maintained on home ventilation. They tolerate being off the ventilator while awake, and have nearly normal bowel habits and growth curves. Two have bilateral ciliary ganglion dysfunction, and one has strabismus. Based on this review, the authors conclude the following. (1) The incidence of the HD associated with OC may be more common than is generally believed (1.8% of all their HD patients have OC). (2) OC should be suspected in any newborn with HD who requires assisted ventilation in the absence of major cardiopulmonary abnormalities. Likewise, HD should be ruled out in any OC case with gastrointestinal dysfunction. (3) Contrary to the previous impression from the literature, the combination of OC and HD should not be considered fatal, because most such patients can be managed successfully and have a reasonable quality of life.(ABSTRACT TRUNCATED AT 250 WORDS)

Congenital difficulties with swallowing and breathing associated with maternal polyhydramnios: neurocristopathy or medullary infarction?

Two babies with congenital difficulties in swallowing and breathing are presented and contrasted. Both were associated with maternal polyhydramnios, but one was due to medullary infarction and the other to a malformation ("neurocristopathy"). In the former case, isolated tenth and twelfth cranial nerve palsies provided the clue as to the correct etiology, whereas the latter baby had dyscoordination of swallowing and breathing with sleep apnea ("Ondine's curse"). It is somewhat ironic that the case without a difficult delivery had the infarct, probably prenatal in onset, whereas the one with a difficult delivery had the congenital malformation. Neural crest cells are known to migrate widely and to develop greatly different functions, but the fact that their central associations of neural tube origin may also be affected has not previously been emphasized in the etiopathogenesis of the congenital malformation. A variety of syndromes with combinations of many defects may be seen in which too many or too few cells are formed, with more or less serious consequences especially for the respiratory and gastrointestinal systems.