Topical Review: Schizencephaly: Clinical Spectrum, Epilepsy, and Pathogenesis

2004 ◽  
Vol 19 (3) ◽  
pp. 313-318
Author(s):  
Tiziana Granata ◽  
Elena Freri ◽  
Claudio Caccia ◽  
Veronica Setola ◽  
Franco Taroni ◽  
...  

After almost 60 years since the original description, we have reviewed the results of the more recent studies on schizencephaly in an attempt to delineate its imaging and clinical spectra of presentation and to point out the still unsettled controversies on its pathogenesis. The clinical picture is mainly based on the presence of motor deficits and mental retardation, but the severity of the clinical picture is extremely variable, mainly related to the size and location of the clefts and to the presence of associated cerebral malformations. By contrast, the outcome of epilepsy, which is present in about half of the cases and drug resistant in a third, is not strictly related to the severity of the malformation. Some clinical and functional magnetic resonance imaging studies have suggested that, beside the features of the anatomic damage, the functional reorganization of a malformed and unaffected cortex is most likely crucial in determining the clinical outcome. Review of the genetic studies and the more recent personal data suggests that the role of the EMX2 gene in schizencephaly, if any, is restricted to a minority of cases, leaving the etiopathogenesis of this brain malformation still a matter of study and debate. ( J Child Neurol 2005;20:313—318).

Author(s):  
Michael Andres ◽  
Mauro Pesenti

Human beings are permanently required to process the world numerically and, consequently, to perform computations to adapt their behaviour and they have developed various calculation strategies, some of them based on specific manipulations of the fingers. In this chapter, we argue that the way we express physically numerical concepts by raising fingers while counting leads to embodied representations of numbers and calculation procedures in the adult brain. To illustrate this, we focus on number and finger interactions in the context of simple arithmetic operations. We show that the fixed order of fingers on the hand provides human beings with unique facilities to increment numerical changes or represent a cardinal value while solving arithmetic problems. In order to specify the influence of finger representation on mental arithmetic both at the cognitive and neural level, we review past and recent findings from behavioural, electrophysiological, and brain imaging studies. We start with anthropological and developmental data showing the role of fingers in the acquisition of arithmetic knowledge, then address the issue of whether number and finger interactions are also observed in adults solving arithmetic problems mentally. We suggest that arithmetic performance depends on the integrity of finger representations in children and adults. Finally, we overview the results of recent functional magnetic resonance imaging (fMRI) studies showing a common brain substrate for finger and number representations during and after the acquisition of arithmetic skills.


2007 ◽  
Vol 19 (3) ◽  
pp. 365-375 ◽  
Author(s):  
S. Pollmann ◽  
K. Mahn ◽  
B. Reimann ◽  
R. Weidner ◽  
M. Tittgemeyer ◽  
...  

The left lateral frontopolar (LFP) cortex showed dimension change-related activation in previous event-related functional magnetic resonance imaging studies of visual singleton feature search with non-brain-lesioned participants. Here, we tested the hypothesis that LFP actively supports changes of attention from the old to the new target-defining dimension in singleton feature search. Singleton detection was selectively slowed in this task when the target-defining dimension changed in patients with left LFP lesions, compared with patients with frontomedian lesions as well as with matched controls without brain lesions. We discuss a potential role of LFP in change detection when the optimal allocation of dimension-based attention is not clearly defined by the task.


2008 ◽  
Vol 20 (4) ◽  
pp. 682-693 ◽  
Author(s):  
Carter Wendelken ◽  
Denis Nakhabenko ◽  
Sarah E. Donohue ◽  
Cameron S. Carter ◽  
Silvia A. Bunge

Brain imaging studies suggest that the rostrolateral prefrontal cortex (RLPFC), is involved in relational reasoning. Functional magnetic resonance imaging (fMRI) studies involving Raven's Progressive Matrices or verbal propositional analogies indicate that the RLPFC is engaged by tasks that require integration across multiple relational structures. Several studies have shown that the RLPFC is more active when people must evaluate an analogy (e.g., Is shoe to foot as glove is to hand?) than when they must simply evaluate two individual semantic relationships, consistent with the hypothesis that this region is important for relational integration. The current fMRI investigation further explores the role of the RLPFC in reasoning and relational integration by comparing RLPFC activation across four different propositional analogy conditions. Each of the four conditions required either relation completion (e.g., Shoe is to foot as glove is to WHAT? → “hand”) or relation comparison (e.g., Is shoe to foot as glove is to hand? → “yes”). The RLPFC was engaged more strongly by the comparison subtask relative to completion, suggesting that the RLPFC is particularly involved in comparing relational structures.


2020 ◽  
Vol 10 (9) ◽  
pp. 603
Author(s):  
Arne May ◽  
Laura Helene Schulte ◽  
Guido Nolte ◽  
Jan Mehnert

Imaging studies help us understand the important role of brainstem and midbrain regions in human trigeminal pain processing without solving the question of how these regions actually interact. In the current study, we describe this connectivity and its dynamics during nociception with a novel analytical approach called Partial Similarity (PS). We developed PS specifically to estimate the communication between individual hubs of the network in contrast to the overall communication within that network. Partial Similarity works on trial-to-trial variance of neuronal activity acquired with functional magnetic resonance imaging. It discovers direct communication between two hubs considering the remainder of the network as confounds. A similar method to PS is Representational Similarity, which works with ordinary correlations and does not consider any external influence on the communication between two hubs. Particularly the combination of Representational Similarity and Partial Similarity analysis unravels brainstem dynamics involved in trigeminal pain using the spinal trigeminal nucleus (STN)—the first relay station of peripheral trigeminal input—as a seed region. The combination of both methods can be valuable tools in discovering the network dynamics in fMRI and an important instrument for future insight into the nature of various neurological diseases like primary headaches.


Author(s):  
Lara Bittmann

On December 31, 2019, WHO was informed of cases of pneumonia of unknown cause in Wuhan City, China. A novel coronavirus was identified as the cause by Chinese authorities on January 7, 2020 and was provisionally named "2019-nCoV". This new Coronavirus causes a clinical picture which has received now the name COVID-19. The virus has spread subsequently worldwide and was explained on the 11th of March, 2020 by the World Health Organization to the pandemic.


2021 ◽  
Vol 10 (3) ◽  
pp. 448
Author(s):  
Federica Piani ◽  
Arrigo F. G. Cicero ◽  
Claudio Borghi

The relationship between serum uric acid (SUA) and hypertension has been a subject of increasing interest since the 1870 discovery by Frederick Akbar Mahomed. Several epidemiological studies have shown a strong association between high SUA levels and the presence or the development of hypertension. Genetic analyses have found that xanthine oxidoreductase (XOR) genetic polymorphisms are associated with hypertension. However, genetic studies on urate transporters and Mendelian randomization studies failed to demonstrate a causal relationship between SUA and hypertension. Results from clinical trials on the role of urate-lowering therapy in the management of patients with hypertension are not uniform. Our study sought to analyze the prognostic and therapeutic role of SUA in the hypertensive disease, from uric acid (UA) biology to clinical trials on urate-lowering therapies.


Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1065
Author(s):  
Armando Rubio-Ramos ◽  
Leticia Labat-de-Hoz ◽  
Isabel Correas ◽  
Miguel A. Alonso

The MAL gene encodes a 17-kDa protein containing four putative transmembrane segments whose expression is restricted to human T cells, polarized epithelial cells and myelin-forming cells. The MAL protein has two unusual biochemical features. First, it has lipid-like properties that qualify it as a member of the group of proteolipid proteins. Second, it partitions selectively into detergent-insoluble membranes, which are known to be enriched in condensed cell membranes, consistent with MAL being distributed in highly ordered membranes in the cell. Since its original description more than thirty years ago, a large body of evidence has accumulated supporting a role of MAL in specialized membranes in all the cell types in which it is expressed. Here, we review the structure, expression and biochemical characteristics of MAL, and discuss the association of MAL with raft membranes and the function of MAL in polarized epithelial cells, T lymphocytes, and myelin-forming cells. The evidence that MAL is a putative receptor of the epsilon toxin of Clostridium perfringens, the expression of MAL in lymphomas, the hypermethylation of the MAL gene and subsequent loss of MAL expression in carcinomas are also presented. We propose a model of MAL as the organizer of specialized condensed membranes to make them functional, discuss the role of MAL as a tumor suppressor in carcinomas, consider its potential use as a cancer biomarker, and summarize the directions for future research.


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