CASE REPORT - Paroxysmal hemichorea after streptococcal infectionclinical and diagnostic findings

Chorea is characterized by abnormal hyperkinetic movements which may be a clinical symptom in a wide array of neurological disorders. This report describes the case of a 7-year-old boy who developed a paroxysmal, right-sided hemichorea three weeks after a throat infection. In correlation to the clinical findings, the area of the left putamen presented with a minimal lesion in diffusion weighted Magnetic resonances imaging which was not further evident two weeks later. Corresponding flour deoxy glucose positron emisson tomograpy showed an increased glucose uptake of the left lentiform nucleus and left frontocentral cortex. Given the serological evidence of streptococcal infection as specific trigger, this case report illustrates not only the importance of neuroimaging data in the differential diagnosis of chorea but also the potential pathophysiological role of immune-mediated reactions as etiological factor. (J Pediatr Neurol 2003; 1(2): 103-106)

New syndrome characterized by hypomyelination with atrophy of the basal ganglia and cerebellum

BACKGROUND AND PURPOSE: Leukoencephalopathies of unknown origin constitute a considerable problem in child neurology. The purpose of our ongoing study of the subject was to define new disease entities among them by using primarily MR imaging pattern recognition. METHODS: We identified seven unrelated patients with a distinct MR imaging pattern consisting of hypomyelination and atrophy of the basal ganglia (neostriatum) and cerebellum (H-ABC). We reviewed the clinical, MR imaging, MR spectroscopic, and laboratory data. RESULTS: Clinically, the patients' diseases were characterized by variably disturbed early development followed by increasing extrapyramidal movement abnormalities, ataxia, and spasticity. Mental capacity was variably affected, but it appeared to be relatively preserved. Parents were not related, and none of their siblings were affected. No metabolic defect was found. Follow-up MR imaging demonstrated atrophy of the cerebral white matter, neostriatum, and cerebellum, which was most pronounced in the most clinically severe cases. Single-voxel proton MR spectroscopic results were normal in the parietal cortex. In the cerebral white matter, myo-inositol and creatine levels were elevated; this finding was compatible with gliosis. N-acetylaspartate and choline levels were normal, suggesting that neither axonal loss nor active demyelination occurred. Proton MR spectroscopic imaging revealed relatively decreased N-acetylaspartate levels in the frontal region. CONCLUSION: The uniform and highly characteristic MR imaging findings, in combination with the similarities in the clinical findings, provide evidence of a distinct nosologic entity. The acronym H-ABC is offered to indicate patients sharing these clinical and MR imaging features

Mutations in the X-Linked Cyclin-Dependent Kinase–Like 5 (CDKL5/STK9) Gene Are Associated with Severe Neurodevelopmental Retardation

Recently, we showed that truncation of the X-linked cyclin-dependent kinase–like 5 (CDKL5/STK9) gene caused mental retardation and severe neurological symptoms in two female patients. Here, we report that de novo missense mutations in CDKL5 are associated with a severe phenotype of early-onset infantile spasms and clinical features that overlap those of other neurodevelopmental disorders, such as Rett syndrome and Angelman syndrome. The mutations are located within the protein kinase domain and affect highly conserved amino acids; this strongly suggests that impaired CDKL5 catalytic activity plays an important role in the pathogenesis of this neurodevelopmental disorder. In view of the overlapping phenotypic spectrum of CDKL5 and MECP2 mutations, it is tempting to speculate that these two genes play a role in a common pathogenic process

Evidence That Paternal Expression of the ε-Sarcoglycan Gene Accounts for Reduced Penetrance in Myoclonus-Dystonia

Myoclonus-dystonia (M-D) is a movement disorder characterized by rapid muscle contractions and sustained twisting and repetitive movements and has recently been associated with mutations in the ε-sarcoglycan gene (SGCE). The mode of inheritance is autosomal dominant with reduced penetrance upon maternal transmission, suggesting a putative maternal imprinting mechanism. We present an apparently sporadic M-D case and two patients from an M-D family with seemingly autosomal recessive inheritance. In both families, we detected an SGCE mutation that was inherited from the patients' clinically unaffected fathers in an autosomal dominant fashion. Whereas, in the first family, RNA expression studies revealed expression of only the mutated allele in affected individuals and expression of the normal allele exclusively in unaffected mutation carriers, the affected individual of the second family expressed both alleles. In addition, we identified differentially methylated regions in the promoter region of the SGCE gene as a characteristic feature of imprinted genes. Using a rare polymorphism in the promoter region in a family unaffected with M-D as a marker, we demonstrated methylation of the maternal allele, in keeping with maternal imprinting of the SGCE gene. Loss of imprinting in the patient with M-D who had biallelic expression of the SGCE gene was associated with partial loss of methylation at several CpG dinucleotides