1,720,968 research outputs found
High frequency of OPA1 mutations causing high ADOA prevalence in south-eastern Sicily, Italy.
Gallus GN, Cardaioli E, Rufa A, Collura M, Da Pozzo P, Pretegiani E, Tumino M, Pavone L, Federico A. High frequency of OPA1 mutations causing high ADOA prevalence in south-eastern Sicily, Italy. Optic atrophy type 1 (OPA1) gene mutation causes autosomal dominant optic atrophy (ADOA, MIM #165500). Prevalence of ADOA ranges from 1:50,000 in most populations to 1:12,000 in Denmark. Seventy members of nine families were analysed for the presence of OPA1 gene mutations by polymerase chain reaction (PCR) and direct sequencing. We identified three OPA1 gene mutations in 48 patients with variable signs of optic atrophy. Two mutations, c.784-21_784-22insAluYb8 and c.876_878delTGT, were found in two different families. The third mutation, c.869G>A, was found in 28 patients from seven families. The haplotype analysis data suggested that the c.869G>A mutation is a founder mutation. Our main result suggests a higher ADOA prevalence in south-eastern Sicily than previously found in Denmark. This is because of not only the founder effect but also to the presence of three different mutations in the geographical area of the study. Our hypothesis is that a combination of social pressure because of blindness and migration factors is involved. In fact, in Siracusa, a provincial capital in south-eastern Sicily, St. Lucy, the patron saint of the blind was born and died
Neuromyotonia as paraneoplastic manifestation of bladder carcinoma
Neuromyotonia(NMT) or Isaacs syndrome is a rare syndrome characterized by continuous spontaneous muscle fiber contraction resulting from hyperexcitability of peripheral nerves often associated with autoimmune disorders and tumours. Here we report an unpublished association of NMT and bladder canc
Optic nerve fibre layer thickness in patients with CADASIL: an optical coherence tomography (OCT) study
Differences in saccade dynamics between spinocerebellar ataxia 2 and late-onset cerebellar ataxias.
The cerebellum is implicated in maintaining the saccadic subsystem efficient for vision by minimizing movement inaccuracy and by learning from endpoint errors. This ability is often disrupted in degenerative cerebellar diseases, as demonstrated by saccade kinetic abnormalities. The study of saccades in these patients may therefore provide insights into the neural substrate underlying saccadic motor control. We investigated the different extent of saccade dynamic abnormalities in spinocerebellar ataxia type 2 and late-onset cerebellar ataxias, genetically undefined and with prevalent cerebellar atrophy. Reflexive and voluntary saccades of different amplitude (10°-18°) were studied in seven patients with spinocerebellar ataxia 2, eight patients with late-onset cerebellar ataxia and 25 healthy controls. Quantitative analysis of saccade parameters and measures of saccade accuracy were performed. Detailed neurological, neurophysiological and magnetic resonance imaging assessment was obtained for each patient. Genetic and laboratory screening for spinocerebellar ataxias and other forms of late-onset cerebellar ataxias were also performed. A lower peak saccade velocity and longer duration was observed in patients with spinocerebellar ataxia 2 with respect to those with late-onset cerebellar ataxia and controls. Unlike subjects with spinocerebellar ataxia 2, patients with late-onset cerebellar ataxia showed main sequence relationships to similar saccades made by normal subjects. Saccades were significantly more inaccurate, namely hypometric, in late-onset cerebellar ataxia than in spinocerebellar ataxia 2 and inaccuracy increased with saccade amplitude. The percentage of hypometric primary saccades and of larger secondary corrective saccades were consistently higher in late-onset cerebellar ataxia than in spinocerebellar ataxia 2 and controls. No other significant differences were found between groups. Two different mechanisms were adopted to redirect the fovea as fast and/or accurately as possible to peripheral targets by the two groups of cerebellar patients. Patients with spinocerebellar ataxia 2 maintained accuracy using slow saccades with longer duration. This reflects prevalent degenerative processes affecting the pontine burst generator and leading to saccade velocity failure. On the other hand, patients with late-onset cerebellar ataxia reached the target with a number of fast inaccurate, mostly hypometric saccades. Different degrees of cerebellar oculomotor vermis involvement may account for differences in optimizing the trade-off between velocity and accuracy in the two groups. In addition, as suggested by spinocerebellar patients having slow saccades that are no longer ballistic, visual feedback might be continuously available during the movement execution to guide the eye to its target
Prosaccade and antisaccade performances in Spinocerebellar Ataxia Type 2 and other genetic ataxias
Going Beyond Counting First Authors in Author Co-citation Analysis
The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Eye movement changes in autosomal dominant spinocerebellar ataxias
Oculomotor abnormalities are common findings in spinocerebellar ataxias (SCAs), a clinically heterogeneous group of neurodegenerative disorders with an autosomal dominant pattern of inheritance. Usually, cerebellar impairment accounts for most of the eye movement changes encountered; as the disease progresses, the involvement of extracerebellar structures typically seen in later stages may modify the oculomotor progression. However, ocular movement changes are rarely specific. In this regard, some important exceptions include the prominent slowing of horizontal eye movements in SCA2 and, to a lesser extent, in SCA3, SCA4, and SCA28, or the executive deficit in SCA2 and SCA17. Here, we report the eye movement abnormalities and neurological pictures of SCAs through a review of the literature. Genetic and neuropathological/neuroimaging aspects are also briefly discussed. Overall, the findings reported indicate that oculomotor analysis could be of help in differential diagnosis among SCAs and contribute to clarify the role of brain structures, particularly the cerebellum, in oculomotor control.
© 2020, Fondazione Società Italiana di Neurologia
Wernicke Encephalopathy After Gastrointestinal Surgery for Cancer: Causes of Diagnostic Failure or Delay.
Wernicke encephalopathy (WE) is a neurological emergency due to thiamine deficiency. We aimed to identify clinical course and causes of diagnostic delay or failure of WE in a group of patients who underwent surgery for gastrointestinal tumors. A retrospective review of clinical, laboratory, neuroimaging, and therapeutic features of 10 patients with WE following abdominal surgery for cancer was carried out. Four patients died; in these subjects, diagnosis was delayed and supplementation of vitamin was absent or likely inadequate. Diagnostic delay or failure was also related to the coexistence of several medical complications at presentation masking typical symptoms of WE. In the surviving patients, outcome was influenced by promptness and type of therapy. Postoperative abdominal bleeding and number of subsequent operations may also had an effect. Postsurgical patients with gastrointestinal tumors may develop a subtle WE. The number of subsequent operations and the severity of postoperative complications may increase the risk of unrecognized WE. The disease should be suspected in postsurgical patients who have unexpected mental status changes, even under prophylactic treatment with vitamins. We suggest that prophylaxis with high doses of thiamine should be undertaken in patients with gastrointestinal tumors before surgery
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