A.M. Camacho

Spontaneous carotid and vertebral artery dissection in children

Carotid and vertebral artery dissection is a rarely reported cause of stroke in childhood and adolescence, especially if there is not a direct trauma to the neck. Four patients, under 15 years of age, presented with an internal carotid artery dissection, and one patient presented with a vertebral artery dissection. They were all making a physical effort when the event occurred. The five patients had ischemic symptoms, and in two the events were preceded by transient ischemic attacks. Headache was associated in four patients. The diagnosis was made by magnetic resonance imaging and angiography, which included transfemoral angiography in two patients. All improved before leaving the hospital, and four patients did not suffer recurrent episodes. The diagnostic accuracy of artery dissection has improved because of noninvasive neuroimaging testing, but it should still be suspected in any pediatric ischemic stroke, especially if there is headache or cervical pain associated.

Cognitive and behavioral profile in females with epilepsy with PDCH19 mutation: Two novel mutations and review of the literature

Mutation in the protocadherin 19 (PCDH19) gene is an increasingly recognized cause of epilepsy in females. This disorder is frequently associated with mental retardation and psychiatric features. We describe two unrelated females with novel PCDH19 missense mutations. One was de novo, and the other was inherited from her unaffected father. Both had mild mental impairment but had remarkable behavioral problems. We reviewed the cognitive and behavioral profiles of previously reported PCDH19-positive cases. Intellectual disability appeared in 75% of patients, ranging from borderline to severe. More than half of the individuals presented behavioral disturbances, which could be divided into two different groups: autistic and non-autistic. The majority of patients with autism already had some degree of cognitive impairment. It appears that seizures tend to diminish or even stop in adolescence, so non-epileptic problems can become the most important and disabling issue in adult patients with PCDH19 mutation.

Modular Procedure to Improve the Application of the Upper-Bound Theorem in Forging

The application of the Upper Bound Theorem (UBT) to plane strain forging processes using Triangular Rigid Blocks (TRB) is not a simple task when trying to adapt the blocks to different workpiece geometries. In this article, a modular procedure is proposed to obtain the best configuration of modules that determines the minimum value of required force to reach the desired state of deformation. This particular approach is called “modular” and the number of modules is modified when forming the workpiece by changing the so called “shape factor,” that is the ratio of the width and the height of the workpiece section to be analyzed. The methodology to follow is carefully explained and minimum curves are determined for different geometrical cases and friction conditions, being the results validated by means of FE analysis.

Analysis of the Energy Vanished by Friction in Tube Drawing Processes with a Fixed Conical Inner Plug by the Upper Bound Method

In this work, an analysis of the energy vanished by friction of thin-walled tube drawing processes in conical converging dies with a fixed conical inner plug has been conducted. The method used for analysis is the upper bound method (UBM), and the plastic deformation zone has been modelled by three triangular rigid zones (TRZ). The tube inner diameter is considered constant during the process, and therefore, a state of plane strain can be assumed. In addition, the existent friction between the external surface of the tube and the die (material-die), as well as that between the inner surface of the tube and the plug (material-plug) has been modeled by Coulomb friction (μ1 and μ2, respectively). Some significant findings emerged from this study are: the establishment of explicit expressions for evaluating the non-dimensional energy vanished by friction in the die and in the plug, the ability to select the plug that enables the process to be performed with a lower requirement of energy under defined conditions, and the detection of coupled effects between the friction coefficients define above.

Vertebral artery fibromuscular dysplasia: an unusual cause of stroke in a 3-year-old child

Fibromuscular dysplasia (FMD) is a systemic arteriopathy which tends to affect renal arteries followed by cervicocranial vessels. It can lead to cerebral infarction if cephalic arteries are involved. FMD is an unusual cause of stroke in childhood that generally affects the carotid area. Only four cases of vertebral FMD and subsequent stroke have been reported previously and we present the youngest patient of all. A healthy 3-year-old female was admitted to Hospital Doce de Octubre in Madrid, Spain with cerebellar infarction. Angiography disclosed basilar artery thrombosis and typical signs of FMD in both vertebral arteries. No other angiographic alteration was noted in the other vessels studied. Her phenotype and other investigations were unremarkable. The patient was treated with anti-aggregation therapy (aspirin) and the outcome was excellent. Investigation of the occurrence in childhood of this kind of arteriopathy may lead to clarification of its natural history and speculation about its unclear pathogenesis.

Analytical Procedure for Geometrical Evaluation of Flat Surfaces Formed by Multiple Indentation Processes

Elementary indentation processes are relatively simple compression processes and they are quite extended in many fields of the industry. Nevertheless, the concatenation of these processes is a new approach and has interest from a technological point of view. In this work the geometry of multiple indentation processes is analyzed on flat surfaces. The state of the formed surface by several types of tools is studied and a model has been developed in order to quantify by means of shape parameters the quality of the theoretical surface depending on the technological and geometrical characteristics of the process.

Levetiracetam-Induced Reversible Autistic Regression

Levetiracetam is a commonly prescribed antiepileptic drug, and is generally well tolerated, but can eventually cause behavioral disturbances. These disturbances seem more frequent in children and in patients with a previous psychiatric history. We report on reversible autistic regression induced by levetiracetam in a 6-year-old girl with spastic cerebral palsy, mild cognitive deficiency, and focal epilepsy. She was diagnosed with pervasive developmental disorder, and demonstrated mild to moderate impairment in pragmatic language and interactions with peers. After the introduction of levetiracetam, she developed stereotypies, and her social and communicative skills deteriorated severely. She also exhibited mood lability. When the medication was discontinued, a dramatic response occurred, with a complete resolution of new abnormal findings. Levetiracetam can provoke unusual behavioral adverse effects in certain patients who are biologically more vulnerable.

Syringomyelia secondary to posthemorrhagic hydrocephalus in a preterm infant.

Syringomyelia is often associated with hydrocephalus, especially in Chiari malformations, but it has never been described as a complication of posthemorrhagic hydrocephalus after preterm birth. We report on a premature infant who presented this exceptional association. He was born at 29 weeks of gestational age and suffered a grade 3 intraventricular hemorrhage. Progressive ventricular dilatation developed despite repeated lumbar punctures, and a ventricular reservoir had to be inserted for cerebrospinal fluid drainage. Two weeks later he presented a flaccid, areflexic paralysis of his left upper limb. Magnetic resonance imaging disclosed a remarkable tetraventricular hydrocephalus and a cervical hydrosyringomyelia expanding from the C(5) to T(1) segments. After shunt surgery, the cephalic perimeter stabilized, and the infant began to move his arm. On follow-up, a minimal paresis of the left hand persisted. This case highlights an unreported outcome of posthemorrhagic hydrocephalus. In this context, syringomyelia should be included in the differential diagnosis of any infant with who presents segmental signs of acute or progressive onset.

An educational software to reinforce the comprehensive learning of materials selection

An educational software, called CalSev 1.0.2, has been developed for supporting the teaching in materials selection seminars. As a case study, a selection of materials for nuclear reactor pressure vessels has been chosen, because it is a representative example of the relationship between chemical composition, mechanical properties, and in‐service behavior. This software has been developed to improve the students’ understanding of the materials selection tasks, providing an interactive user‐friendly platform that allows to modify—in real time—the content of chemical elements and mechanical requirements to obtain a materials performance evaluation. Due to its versatility, this informatics tool represents a great value for educational purposes, with special impact in blended and distance learning, by simplifying the arduous task of materials selection for a wide range of applications and promoting a collaborative working environment by easing the creation of small groups analyzing different study cases. Finally, to evaluate the functionality, interest, user‐friendliness and the educational characteristics of CalSev 1.0.2, a survey among 36 undergraduate students has been carried out.

Clinical Features and Molecular Characterization of a Patient With Muscle-Eye-Brain Disease A Novel Mutation in the POMGNT1 Gene

Muscle-eye-brain disease is a congenital muscular dystrophy characterized by structural brain and eye defects. Here, we describe a 12-year-old boy with partial agenesis of corpus callosum, ventriculomegaly, flattened brain stem, diffuse pachygyria, blindness, profound cognitive deficiencies, and generalized muscle weakness, yet without a clear dystrophic pattern on muscle biopsy. There was no glycosylation of α-dystroglycan and the genetic screening revealed a novel truncating mutation, c.1545delC (p.Tyr516Thrfs*21), and a previously identified missense mutation, c.1469G>A (p.Cys490Tyr), in the protein O-mannose beta-1,2-N-acetylglucosaminyltransferase 1 (POMGNT1) gene. These findings broaden the clinical spectrum of muscle-eye-brain disease to include pronounced hypotonia with severe brain and eye malformations, yet with mild histopathologic changes in the muscle specimen, despite the absence of glycosylated α-dystroglycan.