Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD): a collaborative review of the current understanding

ROHHAD NET in Retrospect: Key Lessons Learned from Five Cases

OBJECTIVES

To present cases of rapid onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) and discuss management insights.

METHODS

Case records of patients fulfilling the criteria for ROHHAD and presenting to the Pediatric Endocrinology Division of All India Institute of Medical Sciences, New Delhi, between July 2019 and June 2024 were reviewed for clinical features, treatments, and outcomes.

RESULTS

Five patients (4 boys, 1 girl) presented at a median age of 4 y (range 3.3-6) with rapidly progressive weight gain as the initial symptom. Autonomic dysregulation and hyperprolactinemia were present in all patients (100%). Sleep disturbances were noted in 4 patients (80%), respiratory support was required for 4 patients (80%), temperature instability in 3 (60%), dysnatremia in 3 (60%), pituitary hormone deficiencies in 3 (60%), behavioral issues in 2 (40%), and neuroectodermal tumor (NET) in 1 patient (20%). Treatment included IVIg for 3 patients with no improvement, home BiPAP support for 1 patient, and unilateral adrenalectomy for a ganglioneuroma in another. Four (80%) patients died during follow-up (mean age at death 5 y); 1 due to sudden cardiorespiratory arrest, and 3 from respiratory tract infections.

CONCLUSIONS

ROHHAD management requires a multimodal approach, addressing pituitary hormone deficiencies, autonomic dysregulation, and screening for hypoventilation and NETs. Emphasis should be on early home respiratory support and monitoring for cardiac rhythm disturbances. Further studies are needed to evaluate the efficacy of immunomodulatory agents.

The Enigma That Is ROHHAD Syndrome: Challenges and Future Strategies

Rapid-onset obesity with hypoventilation, hypothalamic dysfunction, and autonomic dysregulation (ROHHAD) is a rare syndrome presenting in early childhood associated with a high risk of mortality between 50 and 60%. It is characterised by rapid, early onset of obesity between 1.5-7 years, along with central hypoventilation and hypothalamic dysfunction, such as central hypothyroidism, hyperprolactinemia, disorders of sodium and water balance, growth hormone deficiency, adrenocortical insufficiency, or disorders of puberty and features of autonomic dysregulation. Up to half of cases have neural crest tumours, most commonly ganglioneuromas or ganglioneuroblastomas. The incidence of ROHHAD syndrome in any population is unknown. Currently, there is no specific diagnostic or genetic biomarker for ROHHAD, and diagnosis is based on clinical signs and symptoms, which is often challenging, and consequently may be delayed or unrecognised. Early diagnosis is important, as without intervention, ROHHAD is associated with high morbidity and mortality. Aetiology remains unclear; an autoimmune origin has been postulated, with immunosuppressive agents being used with variable benefit. With no cure, multidisciplinary management is largely supportive. Therefore, there are many unanswered questions in ROHHAD syndrome. In this review article, we outline the challenges posed by ROHHAD syndrome, including aetiology, genetics, diagnosis, screening, management, and prognosis. We present research priorities to tackle these issues to improve outcomes.

Case Report: A case of thoracoscopic mediastinal tumor resection in a child with ROHHAD syndrome

Rapid-onset obesity with hypoventilation, hypothalamic dysfunction, and autonomic dysregulation (ROHHAD) is an exceptionally rare condition. This case report highlights a child diagnosed with ROHHAD syndrome, presenting with a mediastinal tumor. ROHHAD syndrome is characterized by early onset obesity, hypothalamic dysfunction, autonomic dysfunction, inadequate ventilation, suspected seizures, and abnormal behavior. The presence of a mediastinal tumor necessitated surgical intervention. Key considerations during surgery included hypernatremia due to hypothalamic dysfunction, potential airway challenges, preoperative anemia, and hemodynamic fluctuations during the removal of the sizable mediastinal tumor. Comprehensive preparations ensured a safe operation. Notably, some children with this syndrome may exhibit symptoms such as decreased gastrointestinal function, polyuria, and thermoregulatory disturbances. Vigilance is essential during anesthesia assessment in these patients. Anesthesiologists should enhance their knowledge of this condition and tailor their management strategies based on individual clinical presentations and the specific planned surgical procedures.

Pathophysiology of Chronic Hypercapnic Respiratory Failure

Chronic hypercapnic respiratory failure occurs in several conditions associated with hypoventilation. The mechanisms underlying the development of chronic hypercapnia include a combination of processes that increase metabolic CO2 production, reduce minute ventilation (V'e), or increase dead space fraction (Vd/Vt). Fundamental to the pathophysiology is a mismatch between increased load and a reduction in the capacity of the respiratory pump to compensate. Though neural respiratory drive may be decreased in a subset of central hypoventilation disorders, it is more commonly increased in attempting to maintain the load-capacity homeostatic balance.

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.

Autonomic nervous system involvement in autoimmune encephalitis and paraneoplastic neurological syndromes

In autoimmune neurological diseases, the autonomic nervous system can be the primary target of autoimmunity (e.g. autoimmune autonomic ganglionopathy), or, more frequently, be damaged together with other areas of the nervous system (e.g. Guillain-Barré syndrome). Patients with autoimmune encephalitis and paraneoplastic neurological syndromes (PNS) often develop dysautonomia; however, the frequency and spectrum of autonomic signs and symptoms remain ill defined except for those scenarios in which dysautonomia is a core feature of the disease. Such is the case of Lambert-Eaton myasthenic syndrome, Morvan syndrome or anti-NMDAR encephalitis; in the latter, patients with dysautonomia have been reported to carry a more severe disease and to retain higher disability than those without autonomic dysfunction. Likewise, the presence of autonomic involvement indicates a higher risk of death due to neurological cause in patients with anti-Hu PNS. However, in anti-Hu and other PNS, as well as in the context of immune checkpoint inhibitors' toxicities, the characterization of autonomic involvement is frequently overshadowed by the severity of other neurological symptoms and signs. When evaluated with tests specific for autonomic function, patients with autoimmune encephalitis or PNS usually show a more widespread autonomic involvement than clinically suggested, which may reflect a potential gap of care when it comes to diagnosing dysautonomia. This review aims to revise the autonomic involvement in patients with autoimmune encephalitis and PNS, using for that purpose an antibody-based approach. We also discuss and provide general recommendations for the evaluation and management of dysautonomia in these patients.