Peripheral nervous system manifestations in a Sandhoff disease mouse model: nerve conduction, myelin structure, lipid analysis

<p>Abstract</p> <p>Background</p> <p>Sandhoff disease is an inherited lysosomal storage disease caused by a mutation in the gene for the β-subunit (<it>Hexb </it>gene) of β-hexosaminidase A (αβ) and B (ββ). The β-subunit together with the GM2 activator protein catabolize ganglioside GM2. This enzyme deficiency results in GM2 accumulation primarily in the central nervous system. To investigate how abnormal GM2 catabolism affects the peripheral nervous system in a mouse model of Sandhoff disease (<it>Hexb-/-</it>), we examined the electrophysiology of dissected sciatic nerves, structure of central and peripheral myelin, and lipid composition of the peripheral nervous system.</p> <p>Results</p> <p>We detected no significant difference in signal impulse conduction velocity or any consistent change in the frequency-dependent conduction slowing and failure between freshly dissected sciatic nerves from the <it>Hexb</it>+/- and <it>Hexb</it>-/- mice. The low-angle x-ray diffraction patterns from freshly dissected sciatic and optic nerves of <it>Hexb</it>+/- and <it>Hexb</it>-/- mice showed normal myelin periods; however, <it>Hexb</it>-/- mice displayed a ~10% decrease in the relative amount of compact optic nerve myelin, which is consistent with the previously established reduction in myelin-enriched lipids (cerebrosides and sulfatides) in brains of <it>Hexb-/- </it>mice. Finally, analysis of lipid composition revealed that GM2 content was present in the sciatic nerve of the <it>Hexb</it>-/- mice (undetectable in <it>Hexb</it>+/-).</p> <p>Conclusion</p> <p>Our findings demonstrate the absence of significant functional, structural, or compositional abnormalities in the peripheral nervous system of the murine model for Sandhoff disease, but do show the potential value of integrating multiple techniques to evaluate myelin structure and function in nervous system disorders.</p

Cerebrovascular disease in neonates: evaluation of four cases Doença cerebrovascular em recém nascidos: avaliação de quatro casos

The clinical and neurological study in four neonates infants with cerebral infarction are reported. The purpose of this study is to call attention for the clinical course, cranial ultrasound, computed tomography and laboratories tests, in order to evaluate the neurological sequelae. A careful evaluation has be taken in order to determine the significance of clinical and laboratory tests for syndromic, topographic and etiologic diagnosis after one year ambulatorial follow-up.<br>Apresentamos o estudo clínico e neurológico de quatro recém nascidos com diagnóstico de doença cerebrovascular. A finalidade do presente estudo é chamar a atenção para o reconhecimento clínico e a valorização dos procedimentos laboratoriais para o diagnóstico sindrômico, topográfico e etiológico, bem como para avaliar as sequelas após um ano de acompanhamento ambulatorial

Prognostic factors for recurrence of a first seizure during childhood Estudo dos fatores prognósticos na recorrência da primeira crise convulsiva na infância

This study was designed with the objective of evaluating the chance of recurrence in our area and to answer questions regarding prognostic factors capable of helping in the management of the first seizure in childhood. One hundred and thirty six children from 1 month to 12 years of age seen at the Pediatric Emergency Division of Hospital de Clínicas de Porto Alegre because of a first seizure with or without triggering factors were included in the study. The follow-up included 121 children. We concluded that family history of seizures, presence of triggering factors at first event, seizure type, seizure duration and paroxysmal electroencephalographic abnormalities were predictive factors for seizure recurrence. The recurrence in this sample was 36.36% during the study. Cumulative recurrence risks were 14.88%, 23.14%, 28.93%, 33.06% and 35.54% to 3, 6, 9, 12 and 15 months, respectively.<br>Este estudo foi elaborado com a finalidade de avaliar a possibilidade de recorrência e de responder a questões referentes a fatores prognósticos capazes de auxiliar no manejo da primeira crise convulsiva na infância. Foram incluídas 136 crianças com idades entre 1 mês e 12 anos atendidas no Setor de Emergência Pediátrica do Hospital de Clínicas de Porto Alegre por ocasião da primeira crise convulsiva, com ou sem fator desencadeante. Foram seguidas 121 crianças por 24 meses, concluindo-se que história familiar de crise convulsiva, existência de fatores desencadeantes na primeira convulsão, tipo de crise, duração da crise e alterações paroxísticas no primeiro eletrencefalograma foram fatores preditivos para a recorrência de crise convulsiva. A recorrência foi de 36,36% no tempo em que durou o estudo. Os riscos acumulados para recorrência nesta amostra foram 14,88%, 23,14%, 28,93%, 33,06% e 35,54% para 3, 6, 9, 12 e 15 meses, respectivamente