Magnetic resonance imaging findings in Hunter syndrome

Direct swallowing training and oral sensorimotor stimulation in preterm infants: a randomised controlled trial

OBJECTIVE

To evaluate the effects of direct swallowing training (DST) alone and combined with oral sensorimotor stimulation (OSMS) on oral feeding ability in very preterm infants.

DESIGN

Blinded, parallel group, randomised controlled trial (1:1:1).

SETTING

Neonatal intensive care unit of a South Korean tertiary hospital.

PARTICIPANTS

Preterm infants born at <32 weeks of gestation who achieved full tube feeding.

INTERVENTIONS

Two sessions per day were provided according to the randomly assigned groups (control: two times per day sham intervention; DST: DST and sham interventions, each once a day; DST+OSMS: DST and OSMS interventions, each once a day).

PRIMARY OUTCOME

Time from start to independent oral feeding (IOF).

RESULTS

Analyses were conducted in 186 participants based on modified intention-to-treat (63 control; 63 DST; 60 DST+OSMS). The mean time from start to IOF differed significantly between the control, DST and DST+OSMS groups (21.1, 17.2 and 14.8 days, respectively, p=0.02). Compared with non-intervention, DST+OSMS significantly shortened the time from start to IOF (effect size: -0.49; 95% CI: -0.86 to -0.14; p=0.02), whereas DST did not. The proportion of feeding volume taken during the initial 5 min, an index of infants' actual feeding ability when fatigue is minimal, increased earlier in the DST+OSMS than in the DST.

CONCLUSIONS

In very preterm infants, DST+OSMS led to the accelerated attainment of IOF compared with non-intervention, whereas DST alone did not. The effect of DST+OSMS on oral feeding ability appeared earlier than that of DST alone.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT02508571).

Diagnostic imaging in patients with mucopolysaccharidosis: important imaging patterns

Background: The need for systematization, generalization and analysis of structural changes in various organs and systems that occur in patients with mucopolysaccharidosis (MPS). MPS is a rare disease, therefore, there is a lack of structured information in Russian publications in the field of radiology. Aims: The purpose of the study is to summarize our own experience, identifying the incidence of changes in various organs and describing the most significant changes and their causes. Identification of more informative and safe diagnostic methods of various organs, taking into account the specificity of changes in MPS. Methods: Retrospectively, 303 children with MPS of different types were examined (the sample included 70 cases verified by the laboratory studies and molecular genetics), the revision of tomograms and radiographs was carried out for the studies from 2015 to 2021. All the patients underwent MRI of the brain and cervical spine, X-ray of the skeletal bones. Results: The analysis of the obtained images revealed the most common changes, such as dysostosis (in 100%; 70 patients), stenosis of the spinal canal at the craniovertebral level (73%; 51 patients), atrophy (47%; 33 patients) and focal lesions of the brain substance (67%; 47 patients), hydrocephalus (28%; 20 patients), expansion of the perivascular spaces (70%; 58 patients). The pathophysiological mechanisms of the occurrence of structural changes have been analyzed and described. Conclusions: The assessment and comparison of various diagnostic methods for different organs and systems has demonstrated that MRI is the most informative imaging method for the assessment of the craniovertebral junction. Given the lower radiation exposure compared to computed tomography, it is preferable to use digital radiography for examining the bones of the extremities.

Quantitative neuroimaging in mucopolysaccharidoses clinical trials

The mucopolysaccharidosis (MPS) disorders are rare lysosomal storage disorders caused by mutations in lysosomal enzymes involved in glycosaminoglycan (GAG) degradation. The resulting intracellular accumulation of GAGs leads to widespread tissue and organ dysfunction. In addition to somatic signs and symptoms, patients with MPS can present with neurological manifestations such as cognitive decline, behavioral problems (e.g. hyperactivity and aggressiveness), sleep disturbances, and/or epilepsy. These are associated with significant abnormalities of the central nervous system (CNS), including white and gray matter lesions, brain atrophy, ventriculomegaly, and spinal cord compression. In order to effectively manage and develop therapies for MPS that target neurological disease, it is important to visualize and quantify these CNS abnormalities. This review describes optimal approaches for conducting magnetic resonance imaging assessments in multi-center clinical studies, and summarizes current knowledge from neuroimaging studies in MPS disorders. The content of the review is based on presentations and discussions on these topics that were held during a meeting of an international group of experts.

Neonatal imitation in context: Sensorimotor development in the perinatal period

More than 35 years ago, Meltzoff and Moore (1977) published their famous article, “Imitation of facial and manual gestures by human neonates.” Their central conclusion, that neonates can imitate, was and continues to be controversial. Here, we focus on an often-neglected aspect of this debate, namely, neonatal spontaneous behaviors themselves. We present a case study of a paradigmatic orofacial “gesture,” namely tongue protrusion and retraction (TP/R). Against the background of new research on mammalian aerodigestive development, we ask: How does the human aerodigestive system develop, and what role does TP/R play in the neonate's emerging system of aerodigestion? We show that mammalian aerodigestion develops in two phases: (1) from the onset of isolated orofacial movementsin uteroto the postnatal mastery of suckling at 4 months after birth; and (2) thereafter, from preparation to the mastery of mastication and deglutition of solid foods. Like other orofacial stereotypies, TP/R emerges in the first phase and vanishes prior to the second. Based upon recent advances in activity-driven early neural development, we suggest a sequence of three developmental events in which TP/R might participate: the acquisition of tongue control, the integration of the central pattern generator (CPG) for TP/R with other aerodigestive CPGs, and the formation of connections within the cortical maps of S1 and M1. If correct, orofacial stereotypies are crucial to the maturation of aerodigestion in the neonatal period but also unlikely to co-occur with imitative behavior.

Brain imaging and genetic risk in the pediatric population, part 1: inherited metabolic diseases

In this article, the genotype-MR phenotype correlation of the most common or clinically important inherited metabolic diseases (IMD) in the pediatric population is reviewed. A nonsystematic search of the PubMed/Medline database of relevant studies about "genotype-phenotype correlation" in IMD was performed. Some MR phenotypes related to specific gene mutations were found, such as bilateral hypertrophy of inferior olives in patients harboring POLG and SURF1 mutations, and central lesions in the cervical spinal cord in patients with nonketotic hyperglycinemia harboring GLRX5 gene mutation.

Cervical spine MRI findings in patients with Mucopolysaccharidosis type II

Mucopolysaccharidosis type II (MPS II; Hunter syndrome) is an X-linked, recessive, lysosomal storage disorder caused by deficiency of iduronate-2-sulfatase (EC 3.1.6.13). The purpose of this report is to describe cervical spine magnetic resonance (MRI) findings in MPS II patients and to correlate them with clinical phenotype. Seven cervical spine MRI examinations from Polish MPS II patients (mean age 11.4 years, median age 8 years, range 5-30) were evaluated. Six patients were classified as neurological (85.7%) and 1 as attenuated (14.3%). Five patients were treated with idursulfase (range 110-260 weeks, mean 195, median 200), while 2 patients never received the treatment. The following features were assessed: periodontoid thickening, spinal stenosis, dens hypoplasia, myelopathy, and vertebral and intervertebral disc abnormalities. Mean age at evaluation was 11 years (range 5-30, median 8). Cervical spine MRI was abnormal in all the patients and the most frequent abnormalities found were dens hypoplasia (100%), periodontoid thickening (100%), disc abnormalities (100%) and spinal stenosis (43%). There was no clear correlation between MRI findings and patients' phenotypes.

Chiari 1 malformation and holocord syringomyelia in hunter syndrome

Compressive cervical myelopathy is a well-known life-threatening complication in mucopolysaccharidosis (MPS) patients. Glycosaminoglycan accumulation in the growing cartilage results in dens dysplasia, atlanto-axial instability, and subsequent periodontoid fibrocartilaginous tissue deposition with upper cervical stenosis.Chiari malformation type 1 (CM1) is a congenital downward cerebellar tonsil ectopia determined by clivus and posterior cranial fossa underdevelopment, possibly leading to progressive spinal cord cavitation (syringomyelia) and severe neurological impairment.We present a boy affected with Hunter syndrome (MPS II) and cerebellar tonsil ectopia who developed a holocord syringomyelia at the age of 6 years. The child underwent atlanto-occipital decompressive surgery with rapid clinical and neuroimaging improvement.Sharing a primary mesenchymal involvement of the cervical-occipital region, the coexistence of CM1 in MPS might be not unexpected and complicate further the disease course. In these patients, strict monitoring and prompt treatment might be of foremost importance for preventing major neurological complications.

Oral feeding readiness in the neonatal intensive care unit

Oral feeding is a complex sensorimotor process that is influenced by many variables, making the introduction and management of oral feeding a challenge for many health care providers. Feeding practice guided by tradition or a trial-and-error approach may be inconsistent and has the potential to delay the progression of oral feeding skills. Oral feeding initiation and management should be based on careful, individualized assessment of the NICU infant and requires an understanding of neonatal physiology and neurodevelopment. The purpose of this article is to help the health care provider with this complex process by (a) defining oral feeding readiness, (b) describing the importance of oral feeding in the NICU and the physiology of feeding, and (c) providing a review of the literature regarding the transition from gavage to oral feeding in the NICU.

Brain and spinal MR imaging findings in mucopolysaccharidoses: a review

MPS represents a group of rare hereditary disorders characterized by multisystem involvement due to intralysosomal GAG accumulation. Among various tissues, both the central and peripheral nervous system are affected in almost all types of the disease. Thus, brain and spinal MR imaging are valuable tools for the assessment of neurologic involvement, and there is evidence that they might be reliable markers demonstrating disease severity and efficacy of treatment options currently used in patients with MPS. We aimed to review the most prominent MR imaging features of patients with MPS, paying attention to the physiopathologic mechanisms responsible for these alterations. Along with the description of neuroimaging findings, existing data in relation to their correlation with the severity of neurologic involvement is discussed, while another topic of great importance is the effect of various therapeutic regimens in the progression of brain and spinal MR imaging alterations. Finally, recent data concerning MR spectroscopy studies in MPS are also critically discussed.

Closed Meningo(encephalo)cele: a new feature in Hunter syndrome

BACKGROUND AND PURPOSE

Hunter syndrome (MPS type II) is a rare X-linked recessive disease caused by lysosomal enzyme iduronate-2-sulfatase deficiency, characterized by frequent and variable brain and skull involvement. Our objective was determine the frequency of closed cephaloceles in a large cohort of subjects affected with Hunter syndrome and to investigate possible correlations with clinical and neuroradiologic findings.

MATERIALS AND METHODS

Brain MR imaging of 33 patients (32 males and 1 female, age range 2.5-30.8 years, mean age 10.4 years) affected with Hunter syndrome were retrospectively evaluated. Eleven (age range 3.6-30.8 years; mean age 15.1) presented with an "attenuated" phenotype, while 22 (age range 2.5-19.1 years; mean age 8.2) had a "severe" phenotype.

RESULTS

A closed cephalocele was detected in 9/33 patients (27%) at the level of anterior and middle fossa in 6 and 3 cases, respectively; 6/9 subjects were affected with the attenuated phenotype and 1/9 suffered from epilepsy. Closed cephaloceles did not show a significant association with other brain and spine MR imaging features of Hunter disease, such as enlargement of perivascular spaces, cisterna magna, pituitary sella, ventricles and subarachnoid spaces, craniosynostosis, dens hypoplasia, white matter abnormalities, spinal stenosis due to periodontoid cap, platyspondylia, or intervertebral disk anomalies.

CONCLUSIONS

Closed cephaloceles are frequent in Hunter syndrome and should be considered a neuroradiologic feature of this disease.

Brain and spine MRI features of Hunter disease: frequency, natural evolution and response to therapy

BACKGROUND

Hunter disease is a rare X-linked mucopolysaccharidosis. Despite frequent neurological involvement, characterizing the severe phenotype, neuroimaging studies are scarce.

OBJECTIVES

To determine frequency and severity of neuroradiological mucopolysaccharidosis-related features; to correlate them with clinical phenotype; to evaluate their natural evolution and the impact of intravenous enzymatic replacement therapy (ERT).

METHODS

Sixty nine brain MRI examinations of 36 Italian patients (mean-age 10.4 years; age-range 2.2-30.8; severe phenotype in 22 patients) were evaluated. Twenty patients had multiple MRIs (median follow-up 3.1 years, range 1-16.9): among them 15 had MRIs before and after ERT, six had repeated MRIs without being on ERT and five while on ERT. Perivascular, subarachnoid and ventricle space enlargement, white matter abnormality (WMA) burden, pituitary sella/skull/posterior fossa abnormalities, periodontoid thickening, spinal stenosis, dens hypoplasia, myelopathy, vertebral and intervertebral disc abnormalities were graded by means of dedicated scales.

RESULTS

Perivascular spaces enlargement (89%), WMAs (97%), subarachnoid space enlargement (83%), IIIrd-ventricle dilatation (100%), pituitary sella abnormalities (80%), cranial hyperostosis (19%), craniosynostosis (19%), enlarged cisterna magna (39%), dens hypoplasia (66%), periodontoid thickening (94%), spinal stenosis (46%), platyspondylia (84%) and disc abnormalities (79%) were frequently detected. WMAs, IIIrd-ventricle dilatation and hyperostosis correlated with the severe phenotype (p < 0.05). Subarachnoid spaces and ventricle enlargement, WMAs and spinal stenosis progressed despite ERT, while other MR features showed minimal or no changes.

CONCLUSIONS

The spectrum of brain and spine MRI abnormalities in Hunter disease is extremely wide and requires a thorough evaluation. WMAs, atrophy/communicating hydrocephalus and spinal stenosis progress over time and might represent possible disease severity markers for new treatment efficacy assessment.

Natural progression of neurological disease in mucopolysaccharidosis type II

OBJECTIVE

Mucopolysaccharidosis type II (MPS II) is a lysosomal storage disorder characterized by insufficiency of the iduronate-2-sulfatase enzyme, which results in excess heparan and dermatan sulfates within the lysosomes of various tissues and organs, including the central nervous system. The purpose of this study was to investigate the natural progression of neurologic disease in a large cohort of patients evaluated with standardized testing at a single institution.

METHODS

During the period of December 2002 to October 2010, patients with MPS II were referred to the Program for Neurodevelopmental Function in Rare Disorders. A retrospective review of patient data was performed, which included the use of detailed questionnaires that addressed medical history, notes from previous health care providers, and the results of a multidisciplinary evaluation that lasted 4 to 6 hours and was performed by a team of neurodevelopmental pediatricians, speech pathologists, psychologists, audiologists, psychometricians, and occupational and physical therapists. Patients were evaluated annually for management of disease progression.

RESULTS

A total of 50 male patients with MPS II were evaluated over 152 encounters. Two distinct subgroups of children were identified. One subset of patients had normal cognitive, speech and language, and adaptive functions whereas the other showed a dramatic decline in these areas. All patients developed fine and gross motor deficits.

CONCLUSION

The natural progression of MPS II manifests as 2 divergent and distinct neurologic phenotypes with similar somatic disease. Patients may have primary neural parenchymal disease with cognitive involvement or may maintain normal cognitive abilities.

Hunter syndrome in an 11-year old girl on enzyme replacement therapy with idursulfase: brain magnetic resonance imaging features and evolution

Mucopolysaccharidosis type II (MPS-II, Hunter disease) is a X-linked recessive disorder. Affected females are extremely rare, mostly due to skewed X chromosome inactivation. A few papers outline MPS-II brain magnetic resonance imaging (MRI) "gestalt" in males, but neuroradiological reports on females are still lacking. We present an 11-year-old girl affected by the severe form of MPS-II who was followed up over a time span of 8 years, focusing on clinical and brain MRI evolution. In the last 2.5 years, the patient has been treated with enzyme replacement therapy (ERT) with idursulfase (Elaprase™, Shire Human Genetic Therapies AB, Sweden). On brain and cervical MRI examination, abnormalities in our patient did not differ from those detected in male patients: J-shaped pituitary sella, enlargement of perivascular spaces, brain atrophy, mild T2-hyperintensity in the paratrigonal white matter, diffuse platyspondylia, and mild odontoid dysplasia with odontoid cup. Brain atrophy progressed despite ERT introduction, whereas perivascular space enlargement did not change significantly before and after ERT. Cognitive impairment worsened independently from the course of white matter abnormality. Despite a profound knowledge of genetic and biochemical aspects in MPS-II, neuroradiology is still poorly characterized, especially in female patients. Spinal and brain involvement and its natural course and evolution after ERT introduction still need to be clarified.