High-Titer Anti-ZSCAN1 Antibodies in a Toddler Clinically Diagnosed with Apparent Rapid-Onset Obesity with Hypothalamic Dysfunction, Hypoventilation, and Autonomic Dysregulation Syndrome.

Severe obesity in young children prompts for a differential diagnosis that includes syndromic conditions. Rapid-Onset Obesity with Hypothalamic Dysfunction, Hypoventilation, and Autonomic Dysregulation (ROHHAD) syndrome is a potentially fatal disorder characterized by rapid-onset obesity associated with hypoventilation, neural crest tumors, and endocrine and behavioral abnormalities. The etiology of ROHHAD syndrome remains to be established, but recent research has been focusing on autoimmunity. We report on a 2-year-old girl with rapid-onset obesity during the first year of life who progressed to hypoventilation and encephalitis in less than four months since the start of accelerated weight gain. The patient had a high titer of anti-ZSCAN1 antibodies (348; reference range < 40), and the increased values did not decline after acute phase treatment. Other encephalitis-related antibodies, such as the anti-NDMA antibody, were not detected. The rapid progression from obesity onset to central hypoventilation with encephalitis warns about the severe consequences of early-onset ROHHAD syndrome. These data indicate that serial measurements of anti-ZSCAN1 antibodies might be useful for the diagnosis and estimation of disease severity. Further research is needed to determine whether it can predict the clinical course of ROHHAD syndrome and whether there is any difference in antibody production between patients with and without tumors.

Type one chiari malformation as a cause of central sleep apnea and hypoventilation in children.

OBJECTIVES: Chiari type 1 malformation (CM1) may occasionally lead to central sleep apnea (CSA). We studied, in a large clinical cohort of pediatric CM1 patients, the effect of CM1 on breathing during sleep. METHODS: This is a retrospective single pediatric pulmonology center study with a systematic evaluation of pediatric CM1 patients under age 18 with polysomnography (PSG) during 2008-2020. Children with syndromes were excluded. All patients had undergone head and spine magnetic resonance imaging. RESULTS: We included 104 children with CM1 with a median age of 7 (interquartile range (IQR) 5-13) years. The median extent of tonsillar descent (TD) was 13 (IQR 10-18) mm. Syringomyelia was present in 19 children (18%). Of all children, 53 (51%) had normal PSG, 35 (34%) showed periodic breathing or central apnea and hypopnea index ≥5 h-1, and 16 (15%) displayed features of compensated central hypoventilation and end-tidal or transcutaneous carbon dioxide 99th percentile level above 50 mmHg. TD had the best predictive value for central breathing disorders. In a linear model, both age (61%) and TD (39%) predicted median breathing frequency (R = 0.33, p < 0.001). CONCLUSIONS: Although severe CSA is a rare complication of brainstem compression in pediatric patients with CM1, short arousal-triggered episodes of periodic breathing and mild compensated central hypoventilation are common. TD shows the best but still poor prediction of the presence of a central breathing disorder. This highlights the use of PSG in patient evaluation. Posterior fossa decompression surgery effectively treats central breathing disorders.

Images: Atypical presentation of congenital central hypoventilation syndrome in an infant with central and obstructive sleep apnea.

Congenital central hypoventilation syndrome (CCHS), a rare disease caused by paired-like homeobox 2B variants, affects control of breathing. We report on a 21-month-old boy with CCHS caused by a novel nonpolyalanine repeat mutation, neuroblastoma, severe obstructive and central sleep apnea, and sleep-related hypoxemia without hypoventilation. At 10 months, due to persistent central sleep apnea during serial polysomnography, bilevel positive airway pressure therapy was initiated despite the absence of hypoventilation. Nonpolyalanine repeat mutations are associated with severe phenotypes requiring continuous assisted ventilation, Hirschsprung's disease, and neural crest tumors; however, our patient had a relatively milder respiratory phenotype requiring sleep-only assisted ventilation without tracheostomy. Although alveolar hypoventilation is the hallmark of CCHS, our patient lacked hypoventilation. Bilevel positive airway pressure could be considered in some infants with CCHS requiring sleep-only assisted ventilation for tracheostomy avoidance. Our case demonstrates the expanding phenotypic spectrum in CCHS and the importance of formulating an individualized care plan. CITATION: Fain ME, Raghunandan S, Pencheva B, Leu RM, Kasi AS. Images: atypical presentation of congenital central hypoventilation syndrome in an infant with central and obstructive sleep apnea. J Clin Sleep Med. 2024;20(3):478-481.

Autoimmune encephalitis with mGluR5 antibodies: A case series from China and review of the literature.

Background: Only 15 patients of autoimmune encephalitis with metabotropic glutamate receptor 5 (mGluR5) antibodies have been reported worldwide since 2011, mostly from western countries. Patients with different genetic backgrounds are necessary to further clarify the clinical phenotype and prognosis of this rare disease. Objective: We initially describe a case series from China to confirm the previous findings, expand the clinical phenotype, and identify the prognostic factors of autoimmune encephalitis with mGluR5 antibodies. Methods: Observational data with follow-up were prospectively collected from autoimmune encephalitis patients with mGluR5 antibodies. Clinical information and outcomes on current and previously reported cases were combined and analyzed. Results: We identified five patients (median age 35 years); two were female. The main clinical manifestations were behavioral/personality changes (five of five, 100%) and cognitive disorders (four of five, 80%), accompanied with other neurologic symptoms. Hypoventilation occurred in two (40%) patients, which was life-threatening. One patient had meningoencephalitis, suggesting a new phenotype in anti-mGluR5 encephalitis. All patients received immunotherapy. At the last follow-up (median 18 months), two (40%) patients showed complete recovery, two (40%) patients showed partial recovery, and one (20%) patient died. One (20%) patient had multiple relapses. Together with the 15 previously reported cases, associated tumors occurred in seven of 12 (58%) Western patients vs. one of eight (13%) Chinese patients. Modified Rankin Scale (mRS) scores at the last follow-up (median 31 months) were available in 16 patients. Patients with bad outcomes (mRS > 2, n = 4) were more likely to have hypoventilation at onset and higher mRS scores at peak of the disease. Conclusions: In patients with different genetic background, as Chinese, the clinical phenotype of anti-mGluR5 encephalitis is similar. Fewer paraneoplastic cases were observed in Chinese patients. Most patients showed good responses to immunotherapy and cancer treatment. The clinical outcomes were favorable in most patients.

Sleep Consequences of Prader-Willi Syndrome.

PURPOSE OF REVIEW: This paper reviews how sleep is impacted in patients with Prader-Willi syndrome (PWS), focusing on sleep-related breathing disturbances and excessive daytime sleepiness (EDS). RECENT FINDINGS: Hypothalamic dysfunction may underlie several aspects of the PWS phenotype. Central sleep apnea (CSA) can persist beyond infancy. Nocturnal hypoventilation is common and may occur without central or obstructive sleep apnea (OSA). Adenotonsillectomy, a mainstay of OSA treatment, may cause velopharyngeal insufficiency. Growth hormone (GH) is considered safe, but close surveillance for OSA remains important. Cardiac autonomic dysfunction occurs during slow wave sleep and may increase the risk of cardiovascular events. EDS and narcolepsy are also common. Modafinil and pitolisant are treatment options currently being studied. Sleep disorders are prevalent in individuals with PWS. Sleep-related breathing disorders present as CSA in infancy and later in life as OSA and hypoventilation. GH therapy has improved the clinical outcomes of patients with PWS, but close surveillance and treatment for OSA is recommended. EDS can persist even after sleep-related breathing disorders are treated, and some individuals may even develop narcolepsy. Early recognition and treatment of sleep-related disorders may prevent morbidity and result in improved survival of patients with PWS.

Obesity-associated sleep hypoventilation and increased adverse postoperative bariatric surgery outcomes in a large clinical retrospective cohort.

STUDY OBJECTIVES: Although obesity hypoventilation syndrome (OHS) is associated with increased morbidity and mortality, post-bariatric surgery OHS risk remains unclear due to often nonsystematic OHS assessments. METHODS: We leverage a clinical cohort with nocturnal CO2 monitoring during polysomnography to address the hypothesis that patients with obesity-associated sleep hypoventilation (OaSH; ie, stage II OHS) have increased adverse postoperative bariatric surgery outcomes. We retrospectively analyzed data from patients undergoing pre-bariatric surgery polysomnography at the Cleveland Clinic from 2011-2018. OaSH was defined by body mass index ≥ 30 kg/m2 and either polysomnography-based end-tidal CO2 ≥ 45 mmHg or serum bicarbonate ≥ 27 mEq/L. Outcomes considered were as follows: intensive care unit stay, intubation, tracheostomy, discharge disposition other than home or 30-day readmission individually and as a composite, and all-cause mortality. Two-sample t test or Wilcoxon rank-sum test for continuous variables and chi-square or Fisher's exact test for categorical variables were used for OaSH vs non-OaSH comparisons. All-cause mortality was compared using Kaplan-Meier estimation and Cox proportional hazards models. RESULTS: The analytic sample (n = 1,665) was aged 45.2 ± 12 years, 20.4% were male, had a body mass index of 48.7 ± 9 kg/m2, and 63.6% were White. OaSH prevalence was 68.5%. OaSH patients were older and more likely to be male with a higher BMI, apnea-hypopnea index, and glycated hemoglobin. The composite outcome was higher in OaSH vs non-OaSH patients (18.9% vs 14.3%, P = .021). Although some individual outcomes were respectively higher in OaSH vs non-OaSH patients, differences were not statistically significant: intubation (1.5% vs 1.3%, P = .81) and 30-day readmission (13.8% vs 11.3%, P = .16). Long-term mortality (median follow-up: 22.9 months) was not significantly different between groups, likely due to overall low event rate (hazard ratio = 1.39, 95% confidence interval: 0.56, 3.42). CONCLUSIONS: In this largest sample to date of systematically phenotyped OaSH in a bariatric surgery cohort, we identify increased postoperative morbidity in those with sleep-related hypoventilation in stage II OHS when a composite outcome was considered, but individual contributors of intubation, intensive care unit admission, and hospital length of stay were not increased. Further study is needed to identify whether perioperative treatment of OaSH improves post-bariatric surgery outcomes. CITATION: Chindamporn P, Wang L, Bena J, et al. Obesity-associated sleep hypoventilation and increased adverse postoperative bariatric surgery outcomes in a large clinical retrospective cohort. J Clin Sleep Med. 2022;18(12):2793-2801.

HIDEA syndrome: A rare cause of congenital hypoventilation in a premature infant.

BACKGROUND: HIDEA (hypotonia, hypoventilation, intellectual disability, dysautonomia, epilepsy and eye abnormalities) syndrome is a rare and novel disease. We describe a premature patient who required extensive work up for his hypoventilation with a diagnosis of HIDEA syndrome. CASE DESCRIPTION: The patient was born to a pair of consanguineous parents at 32-week gestation. His intermittent bradypnoea requiring significant respiratory support during his postnatal clinical course was atypical for bronchopulmonary dysplasia and this required further extensive work up to look for a cause for his hypoventilation. A trio whole exon sequencing was done which identified homozygous variants in P4HTM, in keeping with the diagnosis of autosomal recessive HIDEA syndrome. He is currently doing well on BiPAP 18 cm H2O / 8 cm H2O, Rate 30 breaths per minute in room air and full nasogastric feeding. He also has cortical blindess and severe global developmental delay. CONCLUSION: Early diagnosis is crucial to optimise adequate ventilatory management including early tracheostomy as many require lifelong continuous or intermittent ventilation. This minimises the complications of chronic hypoxia and reduces mortality risk.

Chewing gum: alternative therapy to oxygen intolerance.

Rapid-onset obesity with hypothalamic dysregulation, hypoventilation, and autonomic dysregulation (ROHHAD) syndrome is a rare complex disorder associated with alterations in the endocrine system, autonomic nervous system, and respiratory system. Previously published case reports and studies have noted sleep-disordered breathing in patients with ROHHAD syndrome. Nocturnal respiratory manifestations, which if untreated early by respiratory support, may cause cardiorespiratory arrest and a life-threatening condition. More recently, it has been recognized that children with ROHHAD syndrome have central pauses during wakefulness associated with intermittent oxygen desaturations. We report novel findings of a child with ROHHAD syndrome displaying an irregular breathing pattern and significant central pauses associated with oxygen desaturations during wakefulness, whose respiratory status improved while chewing gum. This was used as an alternative to supplemental oxygen therapy. CITATION: Sunkonkit K, Selvadurai S, Yeh EA, Hamilton J, Narang I. Chewing gum: alternative therapy to oxygen intolerance. J Clin Sleep Med. 2022;18(6):1723-1726.

Images: Sleep-disordered breathing and hypoventilation in a child with obesity and hypothalamic dysfunction.

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) is a rare and potentially lethal disorder of respiratory control, autonomic, and hypothalamic dysfunction of unknown etiology. We report a 15-year-old girl with ROHHAD who developed hyperphagia and rapid weight gain of 16 kg between 2.5 and 4 years of age and cardiorespiratory arrest at 4 years. Initial polysomnography showed central sleep apnea and severe oxygen desaturations without hypoventilation. Mild obstructive sleep apnea and intermittent hypoxemia were identified at 4.5 years, following which nocturnal bilevel positive airway pressure therapy was initiated. At 6 years, she developed sleep-related hypoventilation, and subsequent polysomnograms continued to show obstructive sleep apnea and hypoventilation requiring bilevel positive airway pressure. Clinicians interpreting polysomnograms should become familiar with the evolution of sleep-disordered breathing in ROHHAD and that hypoventilation may develop over time. Our case highlights the importance of serial polysomnography in patients with ROHHAD and optimal ventilatory management. CITATION: Ghosh R, Malik M, Daley TC, Kasi AS. Images: Sleep-disordered breathing and hypoventilation in a child with obesity and hypothalamic dysfunction. J Clin Sleep Med. 2022;18(1):339-342.

Fisiología respiratoria hipoxemia / Hypoxemia

La hipoxemia ocurre producto de una inadecuada captación de oxígeno a nivel pulmonar y se manifiesta como presión arterial de oxígeno menor a 60 mmHg o saturación arterial de oxígeno menor de 90%. Los mecanismos fisiopatológicos por los cuales se puede producir hipoxemia son hipoventilación, alteración del equilibrio ventilación perfusión, shunt cardiaco, alteración de la difusión y disminución de la presión inspirada de oxígeno. La comprensión de estos mecanismos es fundamental para entender su presentación clínica en distintas enfermedades.

Hypoxemia is the name given to inadequate uptake in the lung and is defined as an arterial oxygen pressure less than 60 mmHg or arterial oxygen saturation less than 90%. The pathophysiological mechanisms that can produce hypoxemia are: hypoventilation, ventilation perfusion mismatch, cardiac shunt, diffusion impairment and decreased inspired oxygen pressure. Full comprehension of these mechanism facilitates the understanding of hypoxemia among different diseases.

Rhabdomyolysis due to rosuvastatin in a patient with ROHHAD syndrome.

We report a 13-year-old female with rapid-onset obesity, hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) syndrome, panhypopituitarism, dyslipidemia, type 2 diabetes mellitus, and nonalcoholic fatty liver disease, who developed rhabdomyolysis and acute kidney injury, two weeks after switching from lovastatin to rosuvastatin. She had been on lovastatin for eight years without any adverse effects.

Trastorno de hipoventilación central del sueño en pediatría: causas poco frecuentes / Central hypoventilation disorders sleep-related in pediatrics: unusual causes

Congenital central hypoventilation syndrome (CCHS) and rapid-onset obesity syndrome with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) are rare causes of hypoventilation during sleep in the pediatric population. This group of disorders are characterized by the absence or decrease in the automatic control of ventilation, decreased sensitivity of chemoreceptors to CO2, causing hypoventilation during sleep and even in wakefulness, in the most severe cases. For these reasons it is important to diagnose and treat them promptly. The objective of this review is to provide current and complete literature, to be able to identify, treat and refer this group of children early, and thus reduce the complications and/or associated comorbidities in the short and long term, improving their quality of life.

El síndrome de hipoventilación central congénita (CCHS) y síndrome de obesidad de inicio rápido con disfunción hipotalámica, hipoventilación y desregulación autonómica (ROHHAD), son causas poco comunes de hipoventilación durante el sueño en la población pediátrica. Este grupo de trastornos se caracterizan por ausencia o disminución en el control automático de la ventilación, sensibilidad disminuida de los quimioreceptores al CO2, provocando hipoventilación durante el sueño e incluso en vigilia, en los casos más severos. Por estas razones es importante diagnosticarlos y tratarlos oportunamente. El objetivo de esta revisión es proporcionar literatura actual y completa, para poder identificar, tratar y referir a éste grupo de niños tempranamente, y así disminuir las complicaciones y/o comorbilidades asociadas a corto y largo plazo, mejorando su calidad de vida.

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

STUDY OBJECTIVES: Rapid-onset obesity with hypothalamic dysregulation, hypoventilation, and autonomic dysregulation (ROHHAD) is a rare condition. Little is known about sleep/wake and slow-wave activity in this condition, although the central hypothalamic dysfunction associated with autonomic dysregulation would make the occurrence of SWA deregulation most likely. METHODS: Two children with clinical presentation of ROHHAD syndrome were evaluated, diagnosed, and treated. Their polysomnographic studies were compared with 4 matched children with obstructive sleep apnea and 6 controls. RESULTS: Children that were clinically diagnosed with ROHHAD exhibited significantly weaker slow-wave activity power and shallower slow-wave activity slopes during the first 2 sleep cycles compared with children with obstructive sleep apnea or controls. CONCLUSIONS: This study shows that children with ROHHAD have suppressed slow-wave activity, possibly because of hypothalamic dysregulation that may contribute to their rapid-onset obesity and excessive daytime sleepiness.

ROHHAD(NET) Syndrome: Systematic Review of the Clinical Timeline and Recommendations for Diagnosis and Prognosis.

CONTEXT: Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, autonomic dysregulation and neural crest tumor (ROHHHAD[NET]) is a rare and potentially fatal disease. No specific diagnostic biomarker is currently available, making prompt diagnosis challenging. Since its first definition in 2007, a complete clinical analysis leading to specific diagnosis and follow-up recommendations is still missing. OBJECTIVE: The purpose of this work is to describe the clinical timeline of symptoms of ROHHAD(NET) and propose recommendations for diagnosis and follow-up. DESIGN: We conducted a systematic review of all ROHHAD(NET) case studies and report a new ROHHAD patient with early diagnosis and multidisciplinary care. METHODS: All the articles that meet the definition of ROHHAD(NET) and provide chronological clinical data were reviewed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis individual patient data guidelines. The data were grouped into 7 categories: hypothalamic dysfunction, autonomic dysregulation, hypoventilation, NET, psychiatric symptoms, other clinical manifestations, and outcome. RESULTS: Forty-three individual patient data descriptions were analyzed. The timeline of the disease shows rapid-onset obesity followed shortly by hypothalamic dysfunction. Dysautonomia was reported at a median age of 4.95 years and hypoventilation at 5.33 years, or 2.2 years after the initial obesity. A NET was reported in 56% of the patients, and 70% of these tumors were diagnosed within 2 years after initial weight gain. CONCLUSION: Because early diagnosis improves the clinical management and the prognosis in ROHHAD(NET), this diagnosis should be considered for any child with rapid and early obesity. We propose guidance for systematic follow-up and advise multidisciplinary management with the aim of improving prognosis and life expectancy.

Positional impairment of gas exchange during diaphragm pacing alleviated by increasing amplitude settings in congenital central hypoventilation syndrome.

None: Diaphragm pacing (DP) by phrenic nerve stimulation is a modality of chronic ventilatory support in individuals with congenital central hypoventilation syndrome (CCHS). We report a 9-year-old girl with CCHS who uses DP without tracheostomy during sleep. Her parents report hypoxemia and hypercapnia related to positional changes of the body during sleep requiring frequent adjustment of pacer settings. Overnight polysomnography was performed to titrate DP settings that showed adequate gas exchange in the supine position, but intermittent hypoxemia and hypercapnia were noted in the left decubitus position without obstructive sleep apnea occurring. Subsequently, the DP amplitude settings were increased during polysomnography, thereby identifying and treating positional hypoxemia and hypercapnia in various body positions. Our case emphasizes the importance of polysomnography in children with CCHS using DP to monitor for sleep-disordered breathing and titration of DP settings to achieve optimal oxygenation and ventilation with different body positions during sleep.

Severe Positional Central Sleep Apnea in an Asymptomatic Adult With a PHOX2B Frameshift Mutation.

ABSTRACT: We report an unusual case of an adult patient carrying a germline PHOX2B frameshift mutation and hence was diagnosed with congenital central hypoventilation syndrome. He came to medical attention after the mutation was identified in his daughter who presented with hypoventilation and a neuroblastoma. Although PHOX2B mutations are usually associated with a phenotype of congenital hypoventilation, severe autonomic dysfunction and neural crest tumors, our patient had no complaints at the time of presentation. At polysomnography we found severe positional hypercapnic central sleep apnea, partly responsive to positional therapy. Eventually, he was titrated to noninvasive ventilation with resolution of the central breathing events and, in hindsight, a more refreshing sleep than before. Clinicians working in sleep medicine need to be aware of the variable expression of this rare condition to prevent late cardiorespiratory and neurocognitive complications.

Obstructive Sleep Apnea in Patients With Congenital Central Hypoventilation Syndrome Ventilated by Diaphragm Pacing Without Tracheostomy.

STUDY OBJECTIVES: To determine presence of obstructive sleep apnea (OSA) in patients with congenital central hypoventilation syndrome (CCHS) ventilated by diaphragm pacing (DP) without tracheostomy, and to determine if OSA can be improved by DP setting changes. METHODS: We reviewed polysomnography (PSG) results of 15 patients with CCHS from October 2001 to April 2014, age 15.4 ± 7.8 years, body mass index 22.0 ± 6.0 kg/m2, and 60% female. RESULTS: Of the 22 PSG results obtained for the 15 patients with CCHS, 9 were performed with tracheostomy capped, and 13 were performed after patients underwent decannulation. OSA was present on 6 of 9 tests in patients with tracheostomy capped, including 3 patients with immediate, severe OSA necessitating that the studies be completed with tracheostomy uncapped. OSA was present on 2 of 13 tests in patients in whom decannulation had been performed. Hypoventilation was seen on only one test without OSA. On 2 of 5 tests showing OSA, OSA improved by decreasing DP amplitude settings; apnea-hypopnea index decreased from 11.1 ± 2.5 to 1.8 ± 2.5 events/h; PETCO2 decreased from 57.5 ± 3.5 to 38.5 ± 0.7 torr; SpO2 increased from 76.5 ± 0.7% to 93.0 ± 7.1%. OSA improved in one patient with slight increase in respiratory rate. Settings were manipulated in 4 tests showing OSA; no changes were attempted in the remaining study. One patient was placed on bilevel positive airway pressure with temporary suspension of DP. Age (P < .119), previous adenotonsillectomy (P < .211), and body mass index (P < .112) did not significantly contribute to OSA. CONCLUSIONS: OSA occurs in patients with CCHS ventilated by DP. However, decreasing DP amplitude settings can lessen upper airway obstruction without compromising gas exchange.

Congenital central hypoventilation syndrome associated with Hirschsprung's Disease: case report and literature review / Síndrome de hipoventilação central congênita associada à doença de Hirschsprung: relato de caso e revisão de literatura

Abstract Objective: To report the case of a newborn with recurrent episodes of apnea, diagnosed with Congenital Central hypoventilation syndrome (CCHS) associated with Hirschsprung's disease (HD), configuring Haddad syndrome. Case description: Third child born at full-term to a non-consanguineous couple through normal delivery without complications, with appropriate weight and length for gestational age. Soon after birth he started to show bradypnea, bradycardia and cyanosis, being submitted to tracheal intubation and started empiric antibiotic therapy for suspected early neonatal sepsis. During hospitalization in the NICU, he showed difficulty to undergo extubation due to episodes of desaturation during sleep and wakefulness. He had recurrent episodes of hypoglycemia, hyperglycemia, metabolic acidosis, abdominal distension, leukocytosis, increase in C-reactive protein levels, with negative blood cultures and suspected inborn error of metabolism. At 2 months of age he was diagnosed with long-segment Hirschsprung's disease and was submitted to segment resection and colostomy through Hartmann's procedure. A genetic research was performed by polymerase chain reaction for CCHS screening, which showed the mutated allele of PHOX2B gene, confirming the diagnosis. Comments: This is a rare genetic, autosomal dominant disease, caused by mutation in PHOX2B gene, located in chromosome band 4p12, which results in autonomic nervous system dysfunction. CCHS can also occur with Hirschsprung's disease and tumors derived from the neural crest. There is a correlation between phenotype and genotype, as well as high intrafamilial phenotypic variability. In the neonatal period it can simulate cases of sepsis and inborn errors of metabolism.

Resumo Objetivo: Relatar caso de neonato com episódios de apneias recorrentes, diagnosticado com síndrome de hipoventilação central congênita (SHCC) associada à doença de Hirschsprung (DH), o que configurou síndrome de Haddad. Descrição do caso: Terceiro filho de casal não consanguíneo, nascido a termo, parto normal sem intercorrências, peso e comprimento adequados para idade gestacional. Logo após o nascimento apresentou bradipneia, bradicardia e cianose, foi submetido à intubação orotraqueal e iniciada antibioticoterapia empírica devido à suspeita de sepse neonatal precoce. Durante internação em UTI neonatal evoluiu com dificuldade de extubação devido a episódios de dessaturação durante sono e vigília. Apresentou quadros recorrentes de hipoglicemia, hiperglicemia, acidose metabólica, distensão abdominal, leucocitose, aumento de proteína C reativa, com hemoculturas negativas e suspeita de erro inato do metabolismo. Aos dois meses foi diagnosticada doença de Hirschsprung de segmento longo, foi submetido à ressecção do segmento e colostomia à Hartmann. Feita pesquisa genética por reação em cadeia da polimerase para pesquisa de SHCC, que evidenciou alelo mutado do gene PHOX2B e confirmou o diagnóstico. Comentários: Trata-se de doença genética rara, de herança autossômica dominante, causada por mutação no gene PHOX2B, localizado na banda cromossômica 4p12, que resulta em disfunção do sistema nervoso autônomo. A SHCC também pode cursar com doença de Hirschsprung e tumores derivados da crista neural. Há correlação entre fenótipo e genótipo, além de grande variabilidade fenotípica intrafamiliar. No período neonatal pode simular quadros de sepse e erros inatos do metabolismo.

Congenital central hypoventilation syndrome associated with Hirschsprung's Disease: case report and literature review. / Síndrome de hipoventilação central congênita associada à doença de Hirschsprung: relato de caso e revisão de literatura.

OBJECTIVE: To report the case of a newborn with recurrent episodes of apnea, diagnosed with Congenital Central hypoventilation syndrome (CCHS) associated with Hirschsprung's disease (HD), configuring Haddad syndrome. CASE DESCRIPTION: Third child born at full-term to a non-consanguineous couple through normal delivery without complications, with appropriate weight and length for gestational age. Soon after birth he started to show bradypnea, bradycardia and cyanosis, being submitted to tracheal intubation and started empiric antibiotic therapy for suspected early neonatal sepsis. During hospitalization in the NICU, he showed difficulty to undergo extubation due to episodes of desaturation during sleep and wakefulness. He had recurrent episodes of hypoglycemia, hyperglycemia, metabolic acidosis, abdominal distension, leukocytosis, increase in C-reactive protein levels, with negative blood cultures and suspected inborn error of metabolism. At 2 months of age he was diagnosed with long-segment Hirschsprung's disease and was submitted to segment resection and colostomy through Hartmann's procedure. A genetic research was performed by polymerase chain reaction for CCHS screening, which showed the mutated allele of PHOX2B gene, confirming the diagnosis. COMMENTS: This is a rare genetic, autosomal dominant disease, caused by mutation in PHOX2B gene, located in chromosome band 4p12, which results in autonomic nervous system dysfunction. CCHS can also occur with Hirschsprung's disease and tumors derived from the neural crest. There is a correlation between phenotype and genotype, as well as high intrafamilial phenotypic variability. In the neonatal period it can simulate cases of sepsis and inborn errors of metabolism.

Diaphragm Pacing without Tracheostomy in Congenital Central Hypoventilation Syndrome Patients.

BACKGROUND: Congenital central hypoventilation syndrome (CCHS) is a rare disorder affecting central control of breathing. Thus, patients require lifelong assisted ventilation. Diaphragm pacing (DP) may permit decannulation in those who are ventilator dependent only during sleep. OBJECTIVE: The purpose of this study is to determine if patients with CCHS can be successfully ventilated by DP without tracheostomy. METHODS: We reviewed the records of 18 CCHS patients (mean age 19.5 ± 10.1 years; 44% female) who were ventilated by DP only during sleep. RESULTS: Prior to diaphragm pacer implantation surgery, 14 CCHS patients had been using home portable positive pressure ventilation (PPV) via tracheostomy, 1 had been on PPV via endotracheal tube, and 3 had been using noninvasive PPV (NPPV). Of the patients with tracheostomy prior to DP (n = 15), 11 (73%) were decannulated and ventilated successfully by DP without tracheostomy. Of all the patients reviewed (n = 18), 13 (72%) were successfully ventilated by DP without tracheostomy. Obesity prevented successful DP without tracheostomy in 1 patient, and upper airway obstruction prevented success in another patient. Snoring and/or obstructive apneas were present in some patients, but they were improved by diaphragm pacer changes, adenotonsillectomy, and/or use of nasal steroids. CONCLUSIONS: DP without tracheostomy can be successfully achieved in patients with CCHS. Snoring and obstructive apneas, when present, can be managed by diaphragm pacer changes and medical therapies. Obesity can pose a challenge to successful DP.