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William G. Mackenzie - One of the best experts on this subject based on the ideXlab platform.
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Cervicothoracic myelopathy in children with Morquio Syndrome A: a report of 4 cases.
Journal of pediatric orthopedics, 2014Co-Authors: Wagner A.r. Baratela, Mihir M. Thacker, Kenneth J. Rogers, Murat Oto, Mohan V Belthur, Michael B. Bober, William G. MackenzieAbstract:Background Craniovertebral junction anomalies and C1-C2 instability resulting in myelopathy have been well described in the literature on mucopolysaccharidosis IV (MPS-IV). Spinal involvement in MPS-IV patients, with neurological impairment, other than atlanto-axial instability and thoracolumbar kyphosis, has been scarcely mentioned in the literature. Methods Retrospective clinical and radiologic review of the medical records and imaging studies of 4 individuals with Morquio A Syndrome, who had undergone decompression and fusion of the cervicothoracic spine for myelopathy secondary to cervicothoracic stenosis between 1990 and 2009. Data regarding the presence of kyphosis at the cervicothoracic and upper thoracic spine, and neurological symptoms and signs were obtained. Results There were 3 girls and 1 boy with an average age of 5 years and 11 months at presentation with neurological symptoms. Half of the patients had previously undergone occipitocervical fusion for atlanto-axial instability, whereas the other half were noted to have spinal cord compression at both the upper cervical and cervicothoracic regions, and underwent decompression and fusion at both levels concomitantly. All patients showed postoperative neurological improvement. All patients presented with the classical Morquio Syndrome vertebral morphology. Cervicothoracic kyphosis was found in all of our patients in a varying severity (10 to 35 degrees). Levels of stenosis were similar in 3 patients, C7-T2; and occurred at a lower spinal level, T1-T4, in the remaining patient. Posterior disk bulging and thecal sac indentation were found in all 4 patients. Conclusions Neurological problems secondary to progressive kyphosis and stenosis at the cervicothoracic and upper thoracic spine are seen in children with Morquio Syndrome. Early detection with a careful neurological assessment, whole spine MR imaging, and appropriate surgical treatment can prevent permanent neurological sequelae.
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Upper cervical fusion in children with Morquio Syndrome: intermediate to long-term results.
The Journal of bone and joint surgery. American volume, 2013Co-Authors: Ozgur Dede, Mihir M. Thacker, Kenneth J. Rogers, Murat Oto, Mohan V Belthur, Wagner A.r. Baratela, William G. MackenzieAbstract:Background: Paraplegia or death secondary to upper cervical spine instability and spinal cord compression are known consequences of Morquio Syndrome. Decompression and fusion of the upper cervical spine are indicated to treat spinal cord compression. The purpose of this study was to report the intermediate to long-term results of upper cervical spine fusion in children with Morquio Syndrome. Methods: Twenty patients (nine female and eleven male) with Morquio Syndrome who underwent upper cervical spine fusion at a mean age of sixty-three months were retrospectively analyzed with use of hospital records. Radiographic and clinical results were reported. Results: The average follow-up period was eight years and ten months. Fusion was achieved in all patients except one; this patient underwent a revision with transarticular C1-C2 screw fixation. Seven patients developed symptomatic instability below the fusion mass that required extension of fusion to lower levels at a mean of ninety-one months after the initial operation. Two patients required decompression and fusion of a site other than the upper cervical spine. Asymptomatic cervicothoracic and thoracolumbar kyphosis was prevalent among our patients. All patients were neurologically stable at the time of the latest follow-up visit. Conclusions: Upper cervical spine fusion provides reliable fusion and a stable neural outcome in patients with Morquio Syndrome. However, distal junctional instability is a major problem at long-term follow-up. Kyphotic deformity of the cervicothoracic and thoracolumbar junction may be present in a large number of patients with Morquio Syndrome and evaluation for spinal stenosis at these levels should also be considered. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
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Gait pattern and lower extremity alignment in children with Morquio Syndrome.
Journal of pediatric orthopedics. Part B, 2013Co-Authors: Arjun A. Dhawale, Mihir M. Thacker, William G. Mackenzie, Chris Church, John Henley, Laurens Holmes, Freeman MillerAbstract:The gait in children with Morquio Syndrome (MPS IV) has not been previously described. We reviewed the charts, gait analysis reports, and radiographs of nine children with no previous lower extremity surgery. Children with MPS IV had a slower walking speed, reduced cadence, and reduced stride length as compared with normal (P
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gait pattern and lower extremity alignment in children with Morquio Syndrome
Journal of Pediatric Orthopaedics B, 2013Co-Authors: Arjun A. Dhawale, Mihir M. Thacker, William G. Mackenzie, Chris Church, John Henley, Laurens Holmes, Freeman MillerAbstract:The gait in children with Morquio Syndrome (MPS IV) has not been previously described. We reviewed the charts, gait analysis reports, and radiographs of nine children with no previous lower extremity surgery. Children with MPS IV had a slower walking speed, reduced cadence, and reduced stride length as compared with normal (P<0.05). There was increased knee flexion, genu valgus, and external tibial torsion during stance (P<0.05). Kinetics showed that knee varus moment was increased (P<0.05). There was a strong correlation between genu valgus measured on gait analysis and standing radiographs (r=0.89).
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Anesthetic care and perioperative complications of children with Morquio Syndrome.
Paediatric anaesthesia, 2012Co-Authors: Mary C. Theroux, Tanvi Nerker, Colleen Ditro, William G. MackenzieAbstract:Summary Objectives: Our objective was to make recommendations based on our experience and findings from this study regarding the anesthetic care of children with Morquio Syndrome (MS). We emphasize information not readily available in the Anesthesiology literature. Aim: To describe the unique nature of difficulties, especially the relationship of the head and neck to airway patency. In addition, we aim to examine 83 intubations performed in 28 patients and report on observed preferences. Background: Much of the available literature in Anesthesiology consists of case reports of single or small groups of cases, many describing a nonhomogenous population inclusive of many mucopolysaccharidoses. Methods/Materials: We retrospectively studied 28 children with MS who underwent 108 surgical procedures at our pediatric hospital, which provides multidisciplinary, comprehensive care to children with skeletal dysplasia. Results: Cervical fusion was performed in 22 of 28 patients in our study. Eight children after cervical fusion became difficult to intubate for subsequent surgical procedures. In addition, we found airway abnormalities including tortuous appearance of the trachea and bronchi, evident on chest radiograph, as a result of the abnormalities in the hyaline cartilage and deposits of glycosaminoglycans. Conclusion: Morquio Syndrome results in abnormalities of not only upper airway but also of large airways. Information from 83 intubations of 108 anesthetics (in 28 patients) shows a preference for Glidescope when intubating children with MS. Displacing the tongue anteriorly prior to intubation by manual retraction using a ring forceps or a piece of gauze helps to access the larynx in children with MS.
Shunji Tomatsu - One of the best experts on this subject based on the ideXlab platform.
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bone mineral density in mps iv a Morquio Syndrome type a
Molecular Genetics and Metabolism, 2016Co-Authors: Heidi H Kecskemethy, Francyne Kubaski, H T Harcke, Shunji TomatsuAbstract:Mucopolysaccharidosis IV A (MPS IV A), Morquio A, is caused by deficiency in lysosomal enzyme N-acetylgalactosamine-6-sulfate sulfatase (GALNS), which is responsible for the catabolism of the glycosaminoglycans (GAGs) keratan sulfate (KS) and chondroitin 6-sulfate (C6S). Accumulation of GAGs results in disrupted cartilage formation and skeletal dysplasia. In this prospective cross-sectional study, bone mineral density (BMD) of the whole body (WB), lumbar spine (LS), and lateral distal femur (LDF) was acquired by dual-energy X-ray absorptiometry (DXA) on patients with MPS IV A. Functional abilities, medical history, Tanner score, and laboratory results were reviewed. Age and sex-matched norms were used to calculate Z-scores. Participants included 18 patients (13 females; 16 were unrelated) with a mean age of 21.4years (3.3 to 40.8years). While every patient was able to bear weight, 9 were full-time ambulators. Whole-body DXA could be obtained on only 6 patients (5 full-time ambulators) because of respiratory compromise caused by the position, presence of hardware, or positioning difficulties. Mean WB Z-score was -2.0 (range-0.3 to -4.1). Technical issues invalidating LS DXA in 8 patients included kyphosis at the thoracolumbar junction resulting in overlap of vertebrae in the posterior-anterior view. Mean LS BMD Z-score in full-time ambulators was -3.4 (range-1.6 to -5.0) and in the non-/partial ambulator was -4.0 (-3.7 to -4.2). Lateral distal femur BMD was acquired on every patient, and average Z-scores were -2 or less at all sites; full-time ambulators exhibited higher BMD. In conclusion, the LDF proved to be the most feasible site to measure in patients with MPS IV A. The higher LDF values in ambulators suggest this should be a consideration in promoting bone health for this group.
James E Davison - One of the best experts on this subject based on the ideXlab platform.
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intellectual and neurological functioning in Morquio Syndrome mps iva
Journal of Inherited Metabolic Disease, 2013Co-Authors: James E Davison, Shauna Kearney, Johan Horton, Katharine Foster, Andrew C Peet, Christian J. HendrikszAbstract:Mucopolysaccharidosis type IVa (MPS IVa, Morquio Syndrome OMIM #253000) is a lysosomal storage disease caused by deficiency in N-acetylgalactosamine-6-sulfatase (GALNS, EC 3.1.6.4; encoded by GALNS gene at 16q24.3). Unlike other MPS disorders involving excessive heparan and dermatan sulfate, Morquio Syndrome has not been associated with neurological involvement nor with intellectual impairment as this disorder of keratan sulfate has been described as a purely visceral and skeletal disorder. Neurocognitive assessment was undertaken of MPS IVa patients with age appropriate intellectual tests as well as a Child Behaviour Checklist as part of clinical follow up. Available neuroimaging studies (MRI and MR spectroscopy) were reviewed. Whilst more than half of the overall IQ scores fell in the average range, scores for 3/8 children fell below average. A number of behavioural problems were highlighted, including anxiety/depression, attention and somatic complaints. Subtle neuroimaging abnormalities were demonstrated in over half of the children. These findings present a challenge to existing assumptions about the nature of Morquio A Syndrome. A hypothesis regarding the potential role of calcium signalling is explored.
Ruud A Bank - One of the best experts on this subject based on the ideXlab platform.
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deficiency in n acetylgalactosamine 6 sulfate sulfatase results in collagen perturbations in cartilage of Morquio Syndrome a patients
Molecular Genetics and Metabolism, 2009Co-Authors: Ruud A Bank, Johanna E M Groener, Justus J Van Gemund, Petra D Maaswinkel, Kees A Hoeben, Herman A Schut, Vincent EvertsAbstract:Aim: To investigate extracellular matrix (ECM) characteristics of cortical bone and articular cartilage of patients with Morquio Syndrome A, a lysosomal storage disease caused by a deficiency of N-acetylgalactosamine-6-sulfate sulfatase. Patients and methods: Cartilage, bone, and fibroblasts from 2 unrelated patients with Morquio Syndrome were used. Histological analysis on bone and cartilage was carried out by means of light and electron microscopy. Lysyl hydroxylation and cross-linking of collagen present in bone, cartilage, and fibroblast cultures was determined by reverse-phase high performance liquid chromatography. Results: No histological or biochemical differences were seen in cortical bone; furthermore, no differences were seen in the amount and modification of collagen deposited by fibroblasts. Articular cartilage showed major differences: collagen fibrils show a wider range of fibril diameter, the fibrils are in mean thicker, the lysyl hydroxylation level of the triple helix is strongly decreased, the total amount of pyridinolines is in the lower ranges, and the ratio hydroxylysylpyridinoline to lysylpyridinoline is decreased. Changes were also observed with respect to the arrangement of proteoglycans in the extracellular matrix surrounding the chondrocytes. Conclusion: The collagen of bone and the collagen deposited by fibroblasts is normal, whereas the ECM of cartilage in Morquio Syndrome A patients is affected. Thus, deficiency in N-acetylgalactosamine-6-sulfate sulfatase has an impact on the phenotypic properties of chondrocytes, resulting in the formation of cartilage that is more prone to degeneration, being an explanation for the occurrence of osteoarthritis in Morquio Syndrome A patients at early age.
Christian J. Hendriksz - One of the best experts on this subject based on the ideXlab platform.
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Mortality in patients with Morquio Syndrome a.
JIMD reports, 2014Co-Authors: Christine Lavery, Christian J. HendrikszAbstract:Background: Morquio Syndrome A (mucopolysaccharidosis type IVA) is an autosomal recessive, life-limiting lysosomal storage disease characterized by deficient activity of the enzyme galactosamine-6-sulfatase. The disease affects multiple body systems, and patients require multidisciplinary care from an early age.
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intellectual and neurological functioning in Morquio Syndrome mps iva
Journal of Inherited Metabolic Disease, 2013Co-Authors: James E Davison, Shauna Kearney, Johan Horton, Katharine Foster, Andrew C Peet, Christian J. HendrikszAbstract:Mucopolysaccharidosis type IVa (MPS IVa, Morquio Syndrome OMIM #253000) is a lysosomal storage disease caused by deficiency in N-acetylgalactosamine-6-sulfatase (GALNS, EC 3.1.6.4; encoded by GALNS gene at 16q24.3). Unlike other MPS disorders involving excessive heparan and dermatan sulfate, Morquio Syndrome has not been associated with neurological involvement nor with intellectual impairment as this disorder of keratan sulfate has been described as a purely visceral and skeletal disorder. Neurocognitive assessment was undertaken of MPS IVa patients with age appropriate intellectual tests as well as a Child Behaviour Checklist as part of clinical follow up. Available neuroimaging studies (MRI and MR spectroscopy) were reviewed. Whilst more than half of the overall IQ scores fell in the average range, scores for 3/8 children fell below average. A number of behavioural problems were highlighted, including anxiety/depression, attention and somatic complaints. Subtle neuroimaging abnormalities were demonstrated in over half of the children. These findings present a challenge to existing assumptions about the nature of Morquio A Syndrome. A hypothesis regarding the potential role of calcium signalling is explored.