Evaluation of spinal involvement in children with mucopolysaccharidosis VI: the role of MRI

Objective: To evaluate spinal MRI features of mucopolysaccharidosis (MPS) VI and to assess the correlation with clinical findings. Methods: We retrospectively evaluated spinal MRI scans and clinical findings at the time of imaging in 14 patients (8 male, 6 female) with MPS VI. Craniometric measurements were performed and the images were assessed for bony anomalies, spinal stenosis and spinal cord compression. The degree of cervical cord compression was scored and correlated with neurological examination findings at the time of imaging. Vertebral alignment, structural changes in spinal ligaments and intervertebral discs were also assessed. Results: All patients had cervical stenosis due to bony stenosis and thickened retrodental tissue (median: 6.05 mm, range 3.3-8 mm). Retrodental tissue thickness was found to increase with age (p = 0.042). Compressive myelopathy was detected at upper cervical level in 11 (79%) and lower thoracic level in 2 patients (14%). Significant inverse correlation was found between cervical myelopathy scores and neurological strength scores. The most common bony changes were hypo/dysplastic odontoid; cervical platyspondyly with anterior inferior beaking; thoracic posterior end plate depressions and lumbar posterior scalloping. Kyphosis due to retrolisthesis of the beaked lumbar vertebrae and acute sacrococcygeal angulations were other remarkable findings. Conclusion: MRI is an essential component in evaluation of spinal involvement in MPS VI, and scanning of the entire spine is recommended to rule out thoracic cord compression. Advances in knowledge: This study provides a detailed description of spinal MRI findings in MPS VI and underlines the role of MRI in management of cord compression.Wo

Cognitive And Behavioral Impairment In Mild Hyperphenylalaninemia

As elevated phenylalanine (Phe) is detrimental to brain functions, determining a safe upper limit of blood Phe is important for initiation of treatment plans and setting Phe targets in hyperphenlalaninemic patients. It is accepted that Phe levels below 360 mu mol/L does not impair brain function and hence does not require treatment. Therefore, we aimed to compare cognitive functions and attention-related problems among healthy children and untreated patients with hyperphenylalaninemia (HPA). This study included 41 hyperphenylalaninemic patients ("all HPA group") aged 6-16 years with untreated blood Phe between 240 and 600 mu mol/L and 29 healthy controls. "All HPA group" was further divided into 2 subgroups according to their lifetime median blood Phe levels as "Phe 360-600 mu mol/L" and "Phe 240-360 mu mol/L" groups. Wechsler Intelligence Scale for Children-IV (WISC-IV), Conners' Continuous Performance Test (CPT), Strength and Difficulties Questionnaire (SDQ) and Schedule for Affective Disorders and Schizophrenia for School-Age Children: Present and Lifetime Version (K-SADS-PL) were performed as a comprehensive neurocognitive, attention and behavioral assessment. The study illustrated that "all HPA" patients had significantly lower scores on all WISC-IV indexes compared to controls, except for Working Memory. Both "Phe 360-600 mu mol/L" and "Phe 240-360 mu mol/L" subgroups had lower Full Scale intelligence quotient (IQ) and Verbal Comprehension scores compared to controls. "All HPA" patients also had longer reaction times and more peer problems than controls, indicating attention deficits and behavioral problems. Since the results demonstrated that children with untreated Phe levels between 240-360 mu mol/L are at higher risk for cognitive and attention-related problems, lowering the "safe" upper Phe level should be considered.WoSScopu