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Mather D. Preventing the Development of Dyslexia: A Premature Writing Hypothesis. Percept Mot Skills 2022; 129:468-487. [PMID: 35084244 PMCID: PMC9198397 DOI: 10.1177/00315125221075001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
It has been argued that dyslexia may develop in strongly left eye dominant children through learning to write using ipsilateral, right hemisphere motor pathways. New light on this theory has been cast by recent findings of atypical enhanced corpus callosum white matter in children with dyslexia, reflecting right to left hemisphere communication that is resistant to intensive remedial reading intervention. Enhanced corpus callosum white matter is consistent with uninhibited right to left hemisphere ipsilateral mirror-motor innervation, manifested as frequent mirror-letter writing errors in children with dyslexia. Delaying writing instruction until 7-8 years of age may prevent these errors and as well as the development of dyslexia. During the 7-8 year age period, visual-proprioceptive integration enables a child to mentally map whole word visual images onto kinaesthetic/proprioceptive letter engrams (memory representations). Hypothetically, this process is facilitated by anterior commissure activity involving inter-hemispheric transfer of ipsilateral mirror-to-non mirror motor movement. This postulate, involving delayed writing instruction pending further maturation, also receives indirect support from the remarkable proficiency leap among second graders reading Hebrew as Hebrew involves a leftward orthography in which ipsilateral right to left hemisphere innervation is uninhibited. Additionally, and more directly, normal reading comprehension for learning English among children with agenesis of the corpus callosum suggests that letter-sound decoding is not the sole route to proficient reading comprehension. In this paper, I make recommendations for obtaining empirical evidence of premature writing as a cause of dyslexia.
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Cha JH, Lim JS, Jang YH, Hwang JK, Na JY, Lee JM, Lee HJ, Ahn JH. Altered microstructure of the splenium of corpus callosum is associated with neurodevelopmental impairment in preterm infants with necrotizing enterocolitis. Ital J Pediatr 2022; 48:6. [PMID: 35012576 PMCID: PMC8750779 DOI: 10.1186/s13052-021-01197-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 12/14/2021] [Indexed: 11/16/2022] Open
Abstract
Background Necrotizing enterocolitis (NEC) is a devastating disease in preterm infants with significant morbidities, including neurodevelopmental impairment (NDI). This study aimed to investigate whether NEC is associated with (1) brain volume expansion and white matter maturation using diffusion tensor imaging analysis and (2) NDI compared with preterm infants without NEC. Methods We included 86 preterm infants (20 with NEC and 66 without NEC) with no evidence of brain abnormalities on trans-fontanelle ultrasonography and magnetic resonance imaging at term-equivalent age (TEA). Regional brain volume analysis and white matter tractography were performed to study brain microstructure alterations. NDI was assessed using the Bayley Scales of Infant and Toddler Development-III (BSID-III) at 18 months of corrected age (CA). Results Preterm infants with NEC showed significantly high risk of motor impairment (odds ratio 58.26, 95% confidence interval 7.80–435.12, p < 0.001). We found significantly increased mean diffusivity (MD) in the splenium of corpus callosum (sCC) (p = 0.001) and the left corticospinal tract (p = 0.001) in preterm infants with NEC. The sCC with increased MD showed a negative association with the BSID-III language (p = 0.025) and motor scores (p = 0.002) at 18 months of CA, implying the relevance of sCC integrity with later NDI. Conclusion The white matter microstructure differed between preterm infants with and without NEC. The prognostic value of network parameters of sCC at TEA may provide better information for the early detection of NDI in preterm infants.
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Prasad C, Netravathi M, Kulanthaivelu K, Bhat MD, Pendharkar H. Subacute Sclerosing Panencephalitis: Restricted Diffusion and Clinical Evolution. Neurol India 2022; 70:275-280. [PMID: 35263895 DOI: 10.4103/0028-3886.338737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Background Subacute sclerosing panencephalitis (SSPE) is a rare entity characterized by a protracted course and progressive neurological deterioration. Objective We present patterns of diffusion restriction in eight cases of SSPE, a seldom described imaging attribute. Methods A retrospective analysis was performed on the clinical and neuroimaging data obtained from records of patients with proven SSPE. Patients whose magnetic resonance imaging (MRI) showed evidence of diffusion restriction were included in the analysis. MRI was performed on 3 T and 1.5-T clinical MR systems. Imaging characteristics were reviewed and tabulated by two neuroradiologists. Results Eight SSPE patients (seven men, one woman; age range: 5-15 years; mean age: 11 years) diagnosed and managed at our institute were included in the analysis. Restricted diffusion was evident in the basal ganglia (n = 3), corpus callosum (n = 2), white matter (n = 2) and in bilateral middle cerebellar peduncles (MCP) (n = 2). One patient had diffusion restriction in the genu of the corpus callosum and bilateral frontal cortical white matter. None of the diffusion-restricted lesions showed contrast enhancement or susceptibility. Six cases fulfilled the diagnostic criteria for fulminant SSPE (fSSPE). The extent of neuroparenchymal involvement was greater in this subset of patients. Conclusions Restricted diffusion in SSPE, hitherto infrequently described, can indeed occur in both grey and white matter structures and in both supratentorial and infratentorial compartments. Parenchymal diffusion restriction in SSPE possibly reflects an early time point in the clinical evolution. A greater extent of parenchymal diffusion restriction may portend a rapid downhill course, possibly qualifying for fSSPE.
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Enhanced re-myelination in transthyretin null mice following cuprizone mediated demyelination. Neurosci Lett 2022; 766:136287. [PMID: 34634393 DOI: 10.1016/j.neulet.2021.136287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/01/2021] [Accepted: 10/05/2021] [Indexed: 12/16/2022]
Abstract
Thyroid hormones (THs) impact nearly every tissue in the body, including the adult and developing central nervous system. The distribution of THs around the body is facilitated by specific TH distributor proteins including transthyretin (TTR). In addition to being produced in the liver, TTR is synthesized in the choroid plexus of the brain. The synthesis of TTR by choroid plexus epithelial cells allows transport of THs from the blood into the brain. Adequate supply of THs to the brain is required for developmental myelination of axons and the maintenance of mature myelin throughout adult life, essential for the proper conduction of nerve impulses. Insufficient THs in developing mice results in hypo-myelination (thinner myelin around axons). However, confounding evidence demonstrated that in developing brain of TTR null mice, hyper-myelination of axons was observed in the corpus callosum. This raised the question whether increased myelination occurs during re-myelination in the adult brain following targeted demyelination. To investigate the effect of TTR during re-myelination, cuprizone induced depletion of myelin in the corpus callosum of adult mice was initiated, followed by a period of myelin repair. Myelin thickness was measured to assess re-myelination rates for 6 weeks. TTR null mice displayed expedited rates of early re-myelination, preferentially re-myelinating smaller axons compared to those of wild type mice. Furthermore, TTR null mice produced thicker myelin than wild type mice during re-myelination. These results may have broader implications in understanding mechanisms governing re-myelination, particularly in potential therapeutic contexts for acquired demyelinating diseases such as multiple sclerosis.
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Riedel D, Fellerhoff T, Mierau A, Strüder H, Wolf D, Fischer F, Fellgiebel A, Tüscher O, Kollmann B, Knaepen K. The impact of aging on interhemispheric transfer time and respective sex differences. AGING BRAIN 2022; 2:100040. [PMID: 36908886 PMCID: PMC9997169 DOI: 10.1016/j.nbas.2022.100040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 03/17/2022] [Accepted: 03/19/2022] [Indexed: 11/17/2022] Open
Abstract
Age-related cognitive decline has been attributed to degeneration of the corpus callosum (CC), which allows for interhemispheric integration and information processing [22,69]. Along with decreased structural integrity, altered functional properties of the CC may cause impaired cognitive performance in older adults, yet this aspect of age-related decline remains insufficiently researched [59]. In this context, potential sex-related differences have been proposed [31,58]. A promising parameter, which has been suggested to estimate functional properties of the CC is the interhemispheric transfer time (IHTT), which is ideally obtained from event-related potentials (ERP) evoked by lateralized stimuli [45]. To examine the possible functional consequences of aging with regards to the CC, the present study investigated the IHTT of 107 older (67.69 ± 5.18y) as well as of 23 younger participants (25.09 ± 2.59y). IHTT was obtained using an established letter matching task and targeting early N170 ERP components at posterior electrode sites. The results revealed significantly elongated IHTT in older compared to younger participants, but no significant sex differences. Furthermore, there was a significant positive correlation between IHTT and age, predominantly driven by the female participants. The present findings add support to the notion, that IHTT is subject to age-related elongation reflecting impaired interhemispheric transmission. Age-related decline in women appears to occur at a different age range compared to men.
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Sebastián-Serrano Á, Bianchi C, Di Lauro C, Soria-Tobar L, Álvarez-Castelao B, Díaz-Hernández M. Studying the Role of P2X7 Receptor in Axonal Growth Using In Utero Electroporation Technique. Methods Mol Biol 2022; 2510:355-366. [PMID: 35776336 DOI: 10.1007/978-1-0716-2384-8_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The nervous system is formed by a complex network of neuronal connections. During development, neurons elongate their axons through highly stereotyped anatomical pathways to form precise connections. Defects in these mechanisms are related with neurological disorders. Previous studies have reported that inhibition of the P2X7 receptor, an ionotropic purinergic receptor, promotes axonal growth and branching in cultured neurons. However, little is known about the in vivo mechanism of axonal elongation regulated by P2X7. Here, we detailed a step-by-step method to perform in utero cortical electroporation and quantified the electroporated axons employing accessible and open-source image processing software. This effective surgical procedure manipulates in vivo the gene expression in a discrete population of callosal projection neuron. Thus, a better understanding of the involvement of P2X7 in the in vivo establishment of neuronal circuits might help to clarify the basic biology of several neurodevelopmental disorders and axonal regenerative processes.
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Velayudhan PS, Schwab N, Hazrati LN, Wheeler AL. Temporal patterns of microglial activation in white matter following experimental mild traumatic brain injury: a systematic literature review. Acta Neuropathol Commun 2021; 9:197. [PMID: 34924026 PMCID: PMC8684664 DOI: 10.1186/s40478-021-01297-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Accepted: 11/23/2021] [Indexed: 12/18/2022] Open
Abstract
Mild traumatic brain injuries (mTBIs) are a prevalent form of injury that can result in persistent neurological impairments. Microglial activation has become increasingly recognized as a key process regulating the pathology of white matter in a wide range of brain injury and disease contexts. As white matter damage is known to be a major contributor to the impairments that follow mTBI, microglia have rightfully become a common target of investigation for the development of mTBI therapies and biomarkers. Recent work has demonstrated that the efficacy of microglial manipulation as a therapeutic intervention following injury or disease is highly time-sensitive, emphasizing the importance of advancing our understanding of the dynamics of post-mTBI microglial activation from onset to resolution. Current reporting of microglial activation in experimental studies of mTBI is non-standardized, which has limited our ability to identify concrete patterns of post-mTBI microglial activation over time. In this review, we examine preclinical studies of mTBI that report on microglial activation in white matter regions to summarize our current understanding of these patterns. Specifically, we summarize timecourses of post-mTBI microglial activation in white matter regions of the brain, identify factors that influence this activation, examine the temporal relationship between microglial activation and other post-mTBI assessments, and compare the relative sensitivities of various methods for detecting microglial activation. While the lack of replicated experimental conditions has limited the extent of conclusions that can confidently be drawn, we find that microglia are activated over a wide range of timecourses following mTBI and that microglial activation is a long-lasting outcome of mTBI that may resolve after most typical post-mTBI assessments, with the exception of those measuring oligodendrocyte lineage cell integrity. We identify several understudied parameters of post-mTBI microglial activation in white matter, such as the inclusion of female subjects. This review summarizes our current understanding of the progression of microglial activation in white matter structures following experimental mTBI and offers suggestions for important future research directions.
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Chaves AR, Kenny HM, Snow NJ, Pretty RW, Ploughman M. Sex-specific disruption in corticospinal excitability and hemispheric (a)symmetry in multiple sclerosis. Brain Res 2021; 1773:147687. [PMID: 34634288 DOI: 10.1016/j.brainres.2021.147687] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/04/2021] [Accepted: 10/05/2021] [Indexed: 02/06/2023]
Abstract
Multiple Sclerosis (MS) is a neurodegenerative disease in which pathophysiology and symptom progression presents differently between the sexes. In a cohort of people with MS (n = 110), we used transcranial magnetic stimulation (TMS) to investigate sex differences in corticospinal excitability (CSE) and sex-specific relationships between CSE and cognitive function. Although demographics and disease characteristics did not differ between sexes, males were more likely to have cognitive impairment as measured by the Montreal Cognitive Assessment (MoCA); 53.3% compared to females at 26.3%. Greater CSE asymmetry was noted in females compared to males. Females demonstrated higher active motor thresholds and longer silent periods in the hemisphere corresponding to the weaker hand which was more typical of hand dominance patterns in healthy individuals. Males, but not females, exhibited asymmetry of nerve conduction latency (delayed MEP latency in the hemisphere corresponding to the weaker hand). In males, there was also a relationship between delayed onset of ipsilateral silent period (measured in the hemisphere corresponding to the weaker hand) and MoCA, suggestive of cross-callosal disruption. Our findings support that a sex-specific disruption in CSE exists in MS, pointing to interhemispheric disruption as a potential biomarker of cognitive impairment and target for neuromodulating therapies.
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Maxfield M, Cooper MS, Kavanagh A, Devine A, Gill Atkinson L. On the outside looking in: a phenomenological study of the lived experience of Australian adults with a disorder of the corpus callosum. Orphanet J Rare Dis 2021; 16:512. [PMID: 34906174 PMCID: PMC8670101 DOI: 10.1186/s13023-021-02140-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 11/28/2021] [Indexed: 11/14/2022] Open
Abstract
Background While classified as a rare condition, a congenital disorder of the corpus callosum (DCC) is one of the most commonly identified brain anomalies in newborns, occurring in 1:4000 live births. Advances in imaging techniques have improved early diagnosis for children, yet adults with a DCC—who may present with extreme heterogeneity in cause and impact—often experience challenges in receiving a definitive diagnosis and accessing appropriate services and supports. To date, the dearth of evidence documenting the lived experiences of adults with DCC has made it difficult to determine adequate policy and service responses. This exploratory research aims to address this gap by presenting the first qualitative examination of the experiences and impact of complete or partial agenesis of the corpus callosum among adults. Results Eight face-to-face interviews were conducted with Australian adults, aged 23–72 years, to explore their lived experience. Data was collected in four Australian states from June to August 2017. Thematic and interpretive analyses were employed to analyse data. Three emergent themes described difficulties related to: (1) reactions to the diagnosis; (2) access to supports and key life domains, and (3) identifying as an adult. Interview analysis described lived experiences typically outlining a lifetime of exclusion and misunderstanding from family, educators and disability and health support services. Conclusions This paper contributes to filling the knowledge gap around a rare congenital brain disorder affecting the lives of adults. Findings confirm a considerable lack of information and support for adults living with corpus callosum disorders. Greater professional and societal understanding is needed to improve access to the key life domains of education, employment and social inclusion for adults with a DCC. To instigate truly effective change, social research must tackle the issues of applicability and impact to alter the dominance of uninformed practices, hindered by prevailing myths. This research paves the way for further phenomenological studies in which participant narrative is vital. Further research will elicit stronger policy and service responses for all current and emerging adults with a DCC.
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The diffusion-tensor imaging reveals alterations in water diffusion parameters in acute pediatric concussion. Acta Neurol Belg 2021; 121:1463-1468. [PMID: 32246319 DOI: 10.1007/s13760-020-01347-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 03/24/2020] [Indexed: 10/24/2022]
Abstract
Wide-spread visualization methods which are computed tomography (CT) and magnetic resonance imaging (MRI) are not sensitive to mild traumatic brain injury (mTBI). However, mTBI may cause changes of cerebral microstructure that could be found using diffusion-tensor imaging. The aim of this study is to reveal the impact of acute mTBI (no more than 3 days after trauma) on diffusion parameters in corpus callosum, corticospinal tract, and thalamus in children (aged 14-18). Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were analyzed. Significant increase in FA and decrease in ADC were observed in thalamus. The trend to an increase in FA is observed in corpus callosum.
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Handedness and midsagittal corpus callosum morphology: a meta-analytic evaluation. Brain Struct Funct 2021; 227:545-559. [PMID: 34851460 PMCID: PMC8843913 DOI: 10.1007/s00429-021-02431-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 11/15/2021] [Indexed: 11/17/2022]
Abstract
Following a series of seminal studies in the 1980s, left or mixed hand preference is widely thought to be associated with a larger corpus callosum than right handedness, influencing the interpretation of findings and various theories related to interhemispheric processing, brain lateralisation, and hand preference. Recent reviews, however, find inconsistencies in the literature and cast doubt on the existence of such an association. The present study was conducted to clarify the relationship between hand preference and callosal morphology in a series of meta-analyses. For this purpose, articles were identified via a search in PubMed and Web Of Science databases. Studies reporting findings relating to handedness (assessed as hand preference) and corpus-callosum morphology in healthy participants were considered eligible. On the basis of a total of k = 24 identified studies and databases, random-effects meta-analyses were conducted considering four different group comparisons: (a) dominantly right- (dRH) and left-hand preference (dLH), (b) consistent right (cRH) and non-cRH preference, (c) cRH with mixed-hand preference (MH), and (d) cRH with consistent left-hand hand preference (cLH). For none of these meta-analyses did we find a significant effect of hand preference, and narrow confidence intervals suggest that the existence of population effects larger than 1% explained variance could be excluded. For example, considering the comparison of dRH and dLH (k = 14 studies; 1910 dRH and 646 dLH participants) the mean effect size was Hedge’s g = 0.016 (95% confidence interval: − 0.12 to 0.15; explained variance: < 0.001%). Thus, the common practice of assuming an increase in callosal connectivity based on mixed or left hand preference is likely invalid.
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Hemorrhagic cerebral vasculopathy in Susac syndrome. Acta Neurol Belg 2021; 122:1599-1600. [PMID: 34787817 DOI: 10.1007/s13760-021-01835-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Accepted: 10/29/2021] [Indexed: 10/19/2022]
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Innocenti GM, Schmidt K, Milleret C, Fabri M, Knyazeva MG, Battaglia-Mayer A, Aboitiz F, Ptito M, Caleo M, Marzi CA, Barakovic M, Lepore F, Caminiti R. The functional characterization of callosal connections. Prog Neurobiol 2021; 208:102186. [PMID: 34780864 PMCID: PMC8752969 DOI: 10.1016/j.pneurobio.2021.102186] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 11/05/2021] [Accepted: 11/11/2021] [Indexed: 12/12/2022]
Abstract
The functional characterization of callosal connections is informed by anatomical data. Callosal connections play a conditional driving role depending on the brain state and behavioral demands. Callosal connections play a modulatory function, in addition to a driving role. The corpus callosum participates in learning and interhemispheric transfer of sensorimotor habits. The corpus callosum contributes to language processing and cognitive functions.
The brain operates through the synaptic interaction of distant neurons within flexible, often heterogeneous, distributed systems. Histological studies have detailed the connections between distant neurons, but their functional characterization deserves further exploration. Studies performed on the corpus callosum in animals and humans are unique in that they capitalize on results obtained from several neuroscience disciplines. Such data inspire a new interpretation of the function of callosal connections and delineate a novel road map, thus paving the way toward a general theory of cortico-cortical connectivity. Here we suggest that callosal axons can drive their post-synaptic targets preferentially when coupled to other inputs endowing the cortical network with a high degree of conditionality. This might depend on several factors, such as their pattern of convergence-divergence, the excitatory and inhibitory operation mode, the range of conduction velocities, the variety of homotopic and heterotopic projections and, finally, the state-dependency of their firing. We propose that, in addition to direct stimulation of post-synaptic targets, callosal axons often play a conditional driving or modulatory role, which depends on task contingencies, as documented by several recent studies.
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Hausmann M, Corballis MC, Fabri M. Revisiting the attentional bias in the split brain. Neuropsychologia 2021; 162:108042. [PMID: 34582822 DOI: 10.1016/j.neuropsychologia.2021.108042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 09/10/2021] [Accepted: 09/12/2021] [Indexed: 10/20/2022]
Abstract
Previous research has revealed a strong right bias in allocation of attention in split brain subjects, suggesting that a pathological attention bias occurs not only after unilateral (usually right-hemispheric) damage but also after functional disconnection of intact right-hemispheric areas involved in allocation of attention from those in the left hemisphere. Here, we investigated the laterality bias in spatial attention, as measured with the greyscales task, in two split-brain subjects (D.D.C. and D.D.V.) who had undergone complete callosotomy. The greyscales task requires participants to judge the darker (or brighter) of two left-right mirror-reversed luminance gradients under conditions of free viewing, and offers an efficient means of quantifying pathological attentional biases in patients with unilateral lesions. As predicted, the results of the two split-brain subjects revealed a pathological rightward bias in allocation of attention, suggesting strong dependence on a single hemisphere (the left) in spatial attention, which is opposite to what one expects from people with intact commissures, and is remarkable in that it occurs in free viewing. In that sense both split-brain patients are behaving as though the brain is indeed split, especially in D.D.C. who had undergone partial resection of the anterior commissure in addition to complete callosotomy, whereas the anterior commissure is still intact in D.D.V. The findings support the view that the commissural pathways play a significant role in integration of attentional processes across cerebral hemispheres.
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Lee Y, Choi Y, Seo GH, Kim GH, Keum C, Kim YM, Do HS, Choi J, Choi IH, Yoo HW, Lee BH. Phenotypic and molecular spectra of patients with switch/sucrose nonfermenting complex-related intellectual disability disorders in Korea. BMC Med Genomics 2021; 14:254. [PMID: 34706719 PMCID: PMC8555129 DOI: 10.1186/s12920-021-01104-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 10/19/2021] [Indexed: 02/04/2023] Open
Abstract
Background The switch/sucrose nonfermenting (SWI/SNF) complex is an adenosine triphosphate-dependent chromatin-remodeling complex associated with the regulation of DNA accessibility. Germline mutations in the components of the SWI/SNF complex are related to human developmental disorders, including the Coffin–Siris syndrome (CSS), Nicolaides–Baraitser syndrome (NCBRS), and nonsyndromic intellectual disability. These disorders are collectively referred to as SWI/SNF complex-related intellectual disability disorders (SSRIDDs). Methods Whole-exome sequencing was performed in 564 Korean patients with neurodevelopmental disorders. Twelve patients with SSRIDDs (2.1%) were identified and their medical records were retrospectively analyzed. Results ARID1B, found in eight patients, was the most frequently altered gene. Four patients harbored pathogenic variants in SMARCA4, SMARCB1, ARID2, and SMARCA2. Ten patients were diagnosed with CSS, and one patient without a typical phenotype was diagnosed with ARID1B-related nonsyndromic intellectual disability. Another patient harboring the SMARCA2 pathogenic variant was diagnosed with NCBRS. All pathogenic variants in ARID1B were truncating, whereas variants in SMARCA2, SMARCB1, and SMARCA4 were nontruncating (missense). Frequently observed phenotypes were thick eyebrows (10/12), hypertrichosis (8/12), coarse face (8/12), thick lips (8/12), and long eyelashes (8/12). Developmental delay was observed in all patients, and profound speech delay was also characteristic. Agenesis or hypoplasia of the corpus callosum was observed in half of the patients (6/12). Conclusions SSRIDDs have a broad disease spectrum, including NCBRS, CSS, and ARID1B-related nonsyndromic intellectual disability. Thus, SSRIDDs should be considered as a small but important cause of human developmental disorders.
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Evaluation of the corpus callosum shape in patients with obstructive sleep apnea. Sleep Breath 2021; 26:1201-1207. [PMID: 34665410 PMCID: PMC8524404 DOI: 10.1007/s11325-021-02502-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 09/23/2021] [Accepted: 09/28/2021] [Indexed: 10/26/2022]
Abstract
BACKGROUND The aim of this study was to examine whether or not there was a difference in corpus callosum shape between patients with mild to moderate and severe obstructive sleep apnea (OSA) compared with patients who have simple snoring. METHODS The landmark coordinate data was obtained from the mid-sagittal magnetic resonance imaging (MRI) images of 70 patients who underwent polysomnography. For comparisons, mild and moderate OSA groups were combined and analyses were performed on three groups; simple snoring/control group, mild or moderate OSA group, and severe OSA group. RESULTS The corpus callosum shape of controls was significantly different from that of the severe OSA group. The most prominent deformities were observed in the genu and rostral body of the corpus callosum for the patients with severe OSA. No significant difference was found between mild/moderate OSA group and simple snoring group in terms of global corpus callosum shape. CONCLUSION The data demonstrated that severe OSA patients have structural changes in the corpus callosum and deformities may vary as the severity of disease changes.
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Herrera SL, Sheft M, Mercredi ME, Buist R, Matsuda KM, Martin M. Axon diameter inferences in the human corpus callosum using oscillating gradient spin echo sequences. Magn Reson Imaging 2021; 85:64-70. [PMID: 34662703 DOI: 10.1016/j.mri.2021.10.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/30/2021] [Accepted: 10/12/2021] [Indexed: 10/20/2022]
Abstract
Previous methods used to infer axon diameter distributions using magnetic resonance imaging (MRI) primarily use single diffusion encoding sequences such as pulsed gradient spin echo (PGSE) and are thus sensitive to axons of diameters >5 μm. We applied oscillating gradient spin echo (OGSE) sequences to study human axons in the 1-2 μm range in the corpus callosum, which include the majority of axons constituting cortical connections. The ActiveAx model was applied to calculate the fitted mean effective diameter for axons (AxD) and was compared with values found using histology. Axon diameters from histological data were calculated using three different datasets; true diameters (minimum diameter), a combination of minimum and maximum diameters, and diameters measured across a consistent diffusion direction. The AxD estimates from MRI were 1.8 ± 0.1 μm to 2.34 ± 0.04 μm with an average of 2.0 ± 0.2 μm for the ActiveAx model. The histology AxD values were 1.43 ± 0.02 μm when using the true minimum axon diameters, 5.52 ± 0.02 μm when using the combination of minimum and maximum axon diameters, and 2.20 ± 0.02 μm when collecting measurements across a consistent diffusion direction. This experiment demonstrates the first known usage of OGSE to calculate axon diameters in the human corpus callosum on a 1-2 μm scale. The importance for the model to account for axonal orientation dispersion is indicated by histological results which more closely match the MRI model results depending on the direction of axon diameter measurements. These initial steps using this non-invasive imaging method can be applied to future methodology to develop in vivo axon diameter measurements in human brain tissue.
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Brown WS, Burnett KA, Vaillancourt A, Paul LK. Appreciation of Social Norms in Agenesis of the Corpus Callosum. Arch Clin Neuropsychol 2021; 36:1367-1373. [PMID: 33598684 DOI: 10.1093/arclin/acab003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 12/07/2020] [Accepted: 01/04/2021] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE Anecdotal reports regarding high-functioning adults with agenesis of the corpus callosum (AgCC) suggest that they often lack psychosocial insight. We attempted to determine whether adults with AgCC are able to correctly identify appropriate behaviors within social contexts using the Social Norms Questionnaire. METHOD The Social Norms Questionnaire measures knowledge of norms and judgments of what is appropriate to do in particular contexts. It was administered online to individuals with AgCC and control participants. RESULTS Individuals with AgCC scored significantly lower in understanding social norms than controls, tending to over-adhere to social norms significantly more than controls. There was no significant difference regarding breaking of social norms. CONCLUSION Results suggest that adults with AgCC have deficient judgment regarding the nuances of appropriate behaviors in social contexts. They adhere to social norms concretely, lacking the ability to integrate context in social scenarios to make appropriately nuanced judgments.
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Corpus callosum infarction in uncontrolled diabetes mellitus. Acta Neurol Belg 2021; 121:1335-1337. [PMID: 34184193 DOI: 10.1007/s13760-021-01729-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 06/17/2021] [Indexed: 10/21/2022]
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Dong WQ, Miao HC, Wu F, Li HB. [Effects of electroacupuncture on myelin-related protein in corpus callosum of rats with focal cerebral ischemia]. ZHEN CI YAN JIU = ACUPUNCTURE RESEARCH 2021; 46:721-7. [PMID: 34558236 DOI: 10.13702/j.1000-0607.20210187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE To observe the effect of electroacupuncture(EA)on the expression of myelin basic protein (MBP), axon growth inhibitor Nogo-A and Nogo receptor (NgR) in corpus callosum of rats with focal cerebral ischemia, so as to explore the mechanism of EA underlying improving ischemic white matter injury. METHODS Fourty male SD rats were randomly divided into normal, sham operation, model and EA groups, with 10 rats in each group. The focal cerebral ischemia rat model was established by occlusion of the middle cerebral artery (MCAO). EA was applied to "Baihui"(GV20) and "Zusanli"(ST36) on the left side for 30 min, once daily for 14 days. Neurological function score and the adhensive removal test were used to evaluate neurological deficit severity; Hematoxylin-esion staining was used to observe the pathological changes in myelin of corpus callosum and luxol fast blue(LFB) staining was used to observe the myelin of corpus callosum. Immunohistochemical staining and Western blot were used to detect the expressions of MBP、Nogo-A and NgR in the ischemic corpus callosum. RESULTS After MCAO, the neurological function score was significantly increased (P<0.05), the time required for contact with tape and tape removal was longer (P<0.001), the intensity of LFB staining and the expression of MBP decreased, while the veside area and the expression of Nogo-A and its receptor NgR increased (P<0.01, P<0.05) in the model group relevant to the normal and sham operation groups. The fiber arrangement of the corpus callosum on the ischemic side was disordered and a large amount of myelin sheath was lost in the model group. Following the treatment, the neurological deficit score of EA group was gradually decreased and significantly decreased on the 3rd, 7th and 14th day (P<0.05), and the time to remove the adhesive tape was shortened at the 7th and 14th day (P<0.001). The shape of the corpus callosum in the EA group was close to normal, and the myelin structure was relatively complete. The intensity of LFB staining and the expression of MBP was increased (P<0.05, P<0.01) while the expression of Nogo-A and its receptor NgR were decreased in the EA group relevant to the model group (P<0.01). CONCLUSION EA can play a protective role in myelin of the corpus callosum after cerebral ischemia, which may be related to down-regulating the expressions of Nogo-A and NgR.
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Sudden onset hearing loss as initial presentation of Susac syndrome: a rare case report and brief review. Neurol Sci 2021; 43:683-686. [PMID: 34480640 DOI: 10.1007/s10072-021-05581-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 08/23/2021] [Indexed: 10/20/2022]
Abstract
Susac syndrome is a rare disease presenting with a classic triad of symptoms. These are sensorineural hearing loss, encephalopathy, and branch retinal artery occlusions. Initial presentation is usually headache and symptoms of encephalopathy. Hearing loss is unusual in the early stages but, when it does present, can often lead to a misdiagnosis of sudden sensorineural hearing loss. Hence, neurological and retinal examinations are essential to an accurate diagnosis. In this study, we aimed to raise awareness of Susac syndrome among physicians and facilitate recognition of its manifestation, especially in those patients presenting with hearing loss alone. Identifying Susac syndrome that presents as sudden sensorineural hearing loss can be challenging but a number of case reviews have been reported in recent years and treatment guidelines are available.
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Paradoxical facilitation alongside interhemispheric inhibition. Exp Brain Res 2021; 239:3303-3313. [PMID: 34476535 PMCID: PMC8541949 DOI: 10.1007/s00221-021-06183-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 07/20/2021] [Indexed: 11/03/2022]
Abstract
Neurophysiological experiments using transcranial magnetic stimulation (TMS) have sought to probe the function of the motor division of the corpus callosum. Primary motor cortex sends projections via the corpus callosum with a net inhibitory influence on the homologous region of the opposite hemisphere. Interhemispheric inhibition (IHI) experiments probe this inhibitory pathway. A test stimulus (TS) delivered to the motor cortex in one hemisphere elicits motor evoked potentials (MEPs) in a target muscle, while a conditioning stimulus (CS) applied to the homologous region of the opposite hemisphere modulates the effect of the TS. We predicted that large CS MEPs would be associated with increased IHI since they should be a reliable index of how effectively contralateral motor cortex was stimulated and therefore of the magnitude of interhemispheric inhibition. However, we observed a strong tendency for larger CS MEPs to be associated with reduced interhemispheric inhibition which in the extreme lead to a net effect of facilitation. This surprising effect was large, systematic, and observed in nearly all participants. We outline several hypotheses for mechanisms which may underlie this phenomenon to guide future research.
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Lim J, Sohn H, Kwon MS, Kim B. White Matter Alterations Associated with Pro-inflammatory Cytokines in Patients with Major Depressive Disorder. CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE 2021; 19:449-458. [PMID: 34294614 PMCID: PMC8316659 DOI: 10.9758/cpn.2021.19.3.449] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 09/06/2020] [Accepted: 09/16/2020] [Indexed: 11/18/2022]
Abstract
Objective Regarding the neuroinflammatory theory of major depressive disorder (MDD), little is known about the effect of pro-inflammatory cytokines on white matter (WM) changes in MDD. We aimed to investigate the relationship between pro-inflammatory cytokines and WM alterations in patients with MDD. Methods Twenty-two patients with MDD and 22 healthy controls (HC) were evaluated for brain imaging and pro-inflammatory cytokines including interleukin (IL)-1β, IL-6, IL-8, interferon-γ and tumor necrosis factor (TNF)-α. Tract-based spatial statistics and FreeSurfer were used for brain image analysis. Results The levels of TNF-α and IL-8 were significantly higher in the MDD group than in HC. Compared to HC, lower fractional anisotropy (FA), and higher median diffusivity (MD) and radial diffusivity (RD) values were found in the MDD group for several WM regions. Voxel-wise correlation analysis showed that the level of TNF-α was negatively correlated with FA, and positively correlated with MD and RD in the left body and genu of the corpus callosum, left anterior corona radiata, and left superior corona radiata. Conclusion Our findings suggest that TNF-α may play an important role in the WM alterations in depression, possibly through demyelination.
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Structural properties of corpus callosum are associated differently with verbal creativity and visual creativity. Brain Struct Funct 2021; 226:2511-2521. [PMID: 34430997 DOI: 10.1007/s00429-021-02329-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 06/24/2021] [Indexed: 10/20/2022]
Abstract
Recent neuroimaging studies demonstrate that creativity is related to brain regions across both hemispheres, and the corpus callosum forms the structural basis of inter-hemispheric information exchange. However, the findings regarding the relationship between inter-hemispheric interaction and creativity remain inconsistent, which may be caused by different types of creativity and neural features being adopted. To clarify the inconsistency, and understand how inter-hemispheric interactions are related to different kinds of creativity, we explored the correlation between eight structural measures of the corpus callosum (CC) and two different domains of creativity [verbal creativity (VerC) and visual creativity (VisC)] using a large healthy-adult sample (n = 446). The results showed that VerC was positively correlated with fractional anisotropy (FA) and negatively correlated with the radial diffusivity (RD) of CC; whereas there was no significant association between VisC and CC measures. These results persisted after regressing VisC from VerC, regressing VerC from VisC, and regress out general intelligence from both creativity measures. In summary, we showed that the structural properties of corpus collosum are associated in different ways with two domains of creativity, i.e., verbal creativity and visual creativity, which enriches our understanding of the underlying neural mechanism in different types of creativity.
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Caligiuri ME, Quattrone A, Mechelli A, La Torre D, Quattrone A. Semi-automated assessment of the principal diffusion direction in the corpus callosum: differentiation of idiopathic normal pressure hydrocephalus from neurodegenerative diseases. J Neurol 2021; 269:1978-1988. [PMID: 34426880 DOI: 10.1007/s00415-021-10762-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 07/22/2021] [Accepted: 08/17/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND Idiopathic normal pressure hydrocephalus (iNPH) shares clinical and radiological features with progressive supranuclear palsy (PSP) and Alzheimer's disease (AD). Corpus callosum (CC) involvement in these disorders is well established on structural MRI and diffusion tensor imaging (DTI), but alterations overlap and lack specificity to underlying tissue changes. OBJECTIVE We propose a semi-automated approach to assess CC integrity in iNPH based on the spatial distribution of DTI-derived principal diffusion direction orientation (V1). METHODS We processed DTI data from 121 subjects (Site1: iNPH = 23, PSP = 27, controls = 14; ADNI: AD = 35, controls = 22) to obtain V1, fractional anisotropy (FA) and mean diffusivity (MD) maps. To increase the estimation accuracy of DTI metrics, analyses were restricted to the midsagittal CC portion (± 6 slices from midsagittal plane). Group-wise comparison of normalized altered voxel count in midsagittal CC was performed using Kruskal-Wallis tests, followed by post hoc comparisons (Bonferroni-corrected p < 0.05). ROC analysis was used to evaluate the diagnostic power of DTI alterations compared to callosal volume. RESULTS We found specific changes of V1 distribution in CC splenium of iNPH compared to AD and PSP, while MD and FA showed patterns of alterations common to all disorders. ROC curves showed that, compared to splenial volume, V1 represented the most accurate marker of iNPH diagnosis versus AD and PSP. CONCLUSIONS Our results provide evidence that V1 is a powerful biomarker for distinguishing patients with iNPH from patients with AD or PSP. Indeed, our findings also provide more specific insight into the pathophysiological mechanisms that underlie tissue damage across iNPH and its mimics.
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Wijdicks EFM. Another case of iconodiagnosis: Misattribution of alien hand in Dr. Strangelove? Seizure 2021; 92:51. [PMID: 34418748 DOI: 10.1016/j.seizure.2021.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 08/12/2021] [Indexed: 10/20/2022] Open
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Single-direction diffusion-weighted imaging may be a simple complementary sequence for evaluating fetal corpus callosum. Eur Radiol 2021; 32:1135-1143. [PMID: 34331117 DOI: 10.1007/s00330-021-08176-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 05/20/2021] [Accepted: 06/20/2021] [Indexed: 10/20/2022]
Abstract
OBJECTIVES To explore the feasibility of single-direction diffusion-weighted imaging (DWI) for assessing the fetal corpus callosum (CC). METHODS This prospective study included 67 fetuses with normal CC and 35 fetuses suspected with agenesis of the corpus callosum (ACC). The MR protocols included HASTE, TrueFISP, and single-direction DWI. Two radiologists independently evaluated the optimal visibility and the contrast ratio (CR) of the normal fetal CC. The Chi-squared test or Fisher's exact test was used to compare the proportions of "good" visibility (score ≥ 3, and the CC was almost/entirely visible) between single-direction DWI and HASTE/TrueFISP. The CR difference between single-direction DWI and HASTE/TrueFISP was detected using the paired t-test. The diagnostic accuracies were determined by comparison with postnatal imaging. In fetuses suspected of ACC, we measured and compared the length and area of the mid-sagittal CC in the single-direction DWI images. RESULTS The proportion of "good" visibility in single-direction DWI was higher than that in HASTE/TrueFISP, with p < 0.0001. The mean CR from single-direction DWI was also higher than that of TrueFISP and HASTE (both with p < 0.0001). The diagnostic accuracy of the single-direction DWI combined with HASTE/TrueFisp (97.1%, 34/35) was higher than that of the Haste/TrueFISP (74.3%, 26/35) (p = 0.013). The length and area of the PACC (p < 0.001, p = 0.001, respectively) and HCC (p < 0.001, p = 0.018, respectively) groups were significantly lower than those of the normal group. CONCLUSIONS The single-direction DWI is feasible in displaying fetal CC and can be a complementary sequence in diagnosing ACC. KEY POINTS • We suggest a simple method for the display of the fetal CC. • The optimal visibility and contrast ratio from single-direction DWI were higher than those from HASTE and TrueFISP. • The diagnostic accuracy of the single-direction DWI combined with HASTE/TrueFISP sequences (97.1%, 34/35) was higher than that of the Haste/TrueFISP (74.3%, 26/35).
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Kale A, Joshi P, Kelkar AB. Restricted diffusion in the corpus callosum: A neuroradiological marker in hypoxic-ischemic encephalopathy. Indian J Radiol Imaging 2021; 26:487-492. [PMID: 28104944 PMCID: PMC5201080 DOI: 10.4103/0971-3026.195795] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Background: Restricted diffusion within the splenium of the corpus callosum has been described by other authors in various conditions, however, restricted diffusion in the entire corpus callosum or isolated involvement of the splenium, genu, or body has been infrequently reported on magnetic resonance imaging (MRI) in neonatal hypoxic–ischemic encephalopathy. We report a series of cases showing different patterns of involvement. Methods and Materials: Perinatal imaging with MRI including diffusion-weighted imaging was performed in 40 neonates with hypoxic–ischemic encephalopathy, including 11 premature neonates. Sixteen out of 40 patients demonstrated restricted diffusion within the corpus callosum. Out of 16 patients, 9 showed restricted diffusion in the entire corpus callosum, 4 had isolated splenium involvement, 2 had body and splenium signal abnormality, and 1 showed diffusion restriction only in the genu. Conclusions: Changes in the corpus callosum were also associated with more severe clinical presentation of encephalopathy. Restricted diffusion within the corpus callosum in infants with hypoxic–ischemic encephalopathy is often associated with extensive brain injury and appears to be an early neuroradiologic marker of adverse neurologic outcome.
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Fan TH, Kharal GA, Biedny J, Ahrens C, Gomes J. Callosal Diffusion-Restriction in Patients with Intracranial Hemorrhage. J Stroke Cerebrovasc Dis 2021; 30:105951. [PMID: 34298426 DOI: 10.1016/j.jstrokecerebrovasdis.2021.105951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 06/08/2021] [Accepted: 06/13/2021] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE We aim to report the incidence and clinical characteristics of patients who were found to have diffusion restricting lesions of the corpus callosum (CC) on Diffusion-weighted imaging (DWI) on magnetic resonance imaging (MRI) following intracranial hemorrhage (ICH). DESIGN/METHODS A retrospective cross-sectional analysis was performed of medical records of all adult patients admitted to a single tertiary center with a primary diagnosis of ICH and received nicardipine infusion over a 2-year period. Patients without MRI brain available or patients who underwent digital subtraction angiography (DSA) prior to MRI were excluded. ICH and intraventricular hemorrhage (IVH) volumes and scores were calculated. MRI brain scans were evaluated for presence and locations of DWI lesions. RESULTS Among 162 patients who met inclusion criteria, 6 patients (4%, median age 53, range 37-71, 100% male, 33% white) were found to have DWI lesions in the CC with a median ICH volume of 17ml (range 1-105ml). The ICH locations were lobar (n=3), deep (n=2) and cerebellum (n=1). All patients (100%) had intraventricular hemorrhage (IVH) with median IVH volume of 25ml (range 2.7-55ml). Four patients were on levetiracetam. No identifiable infections or metabolic abnormalities were found among these patients. All but one patient had normal DSA. Follow up MRI was only available in one patient and showed no reversibility at 14 days. CONCLUSION Although rare, diffusion restricting corpus callosum lesions can be seen in patients with ICH, especially in patients with IVH. The etiology and clinical significance of these lesions remains unknown and warrant further research.
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Improved outcomes associated with maximal extent of resection for butterfly glioblastoma: insights from institutional and national data. Acta Neurochir (Wien) 2021; 163:1883-1894. [PMID: 33871698 DOI: 10.1007/s00701-021-04844-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 04/08/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND Butterfly glioblastomas (bGBMs) are grade IV gliomas that infiltrate the corpus callosum and spread to bilateral cerebral hemispheres. Due to the rarity of cases, there is a dearth of information in existing literature. Herein, we evaluate clinical and genetic characteristics, associated predictors, and survival outcomes in an institutional series and compare them to a national cohort. METHODS We identified all adult patients with bGBM treated at Brigham & Women's Hospital (2008-2018). The National Cancer Database (NCDB) was also queried for bGBM patients. Survival was analyzed with Kaplan-Meier methods, and Cox models were built to assess for predictive factors. RESULTS Of 993 glioblastoma patients, 62 cases (6.2%) of bGBM were identified. Craniotomy for resection was attempted in 26 patients (41.9%), with a median volumetric extent of resection (vEOR) of 72.3% (95% confidence interval [95%CI] 58.3-82.1). The IDH1 R132H mutation was detected in two patients (3.2%), and MGMT promoter was methylated in 55.5% of the assessed cases. In multivariable regression, factors predictive of longer OS were increased vEOR, MGMT promoter methylation, and receipt of adjuvant therapy. Median OS for the resected cases was 11.5 months (95%CI 7.7-18.8) vs. 6.3 (95%CI 5.1-8.9) for the biopsied. Of 21,353 GBMs, 719 (3.37%) bGBM patients were identified in the NCDB. Resection was more likely to be pursued in recent years, and GTR was independently associated with prolonged OS (p < 0.01). CONCLUSION Surgical resection followed by adjuvant chemoradiation is associated with significant survival gains and should be pursued in carefully selected bGBM patients.
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Addiego FM, Zajur K, Knack S, Jamieson J, Rayhan RU, Baraniuk JN. Subcortical brain segment volumes in Gulf War Illness and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Life Sci 2021; 282:119749. [PMID: 34214570 DOI: 10.1016/j.lfs.2021.119749] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 05/20/2021] [Accepted: 06/11/2021] [Indexed: 01/29/2023]
Abstract
AIMS There is controversy about brain volumes in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (CFS) and Gulf War Illness (GWI). Subcortical regions were assessed because of significant differences in blood oxygenation level dependent signals in the midbrain between these diseases. MATERIALS AND METHOD Magnetization-prepared rapid acquisition with gradient echo (MPRAGE) images from 3 Tesla structural magnetic resonance imaging scans from sedentary control (n = 34), CFS (n = 38) and GWI (n = 90) subjects were segmented in FreeSurfer. Segmented subcortical volumes were regressed against intracranial volume and age, then iteratively analyzed by multivariate general linear modeling with disease status, gender and demographics as independent co-variates. KEY FINDINGS The optimal model for all subjects used disease status and gender as fixed factors with independent variables eliminated after iteration. Volumes of anterior and midanterior corpus callosum were significantly larger in GWI than CFS. Gender was a significant variable for many segment volumes, and so female and male subjects were analyzed separately. CFS females had smaller left putamen, right caudate and left cerebellum white matter than control women. CFS males had larger left hippocampus than GWI males. Orthostatic status and posttraumatic distress syndrome were not significant covariates. SIGNIFICANCE CFS and GWI were appropriate "illness controls" for each other. The different patterns of adjusted segment volumes suggested that sexual dimorphisms contributed to pathological changes. Previous volumetric studies may need to be reevaluated to account for gender differences. The findings are framed by comparison to the spectrum of magnetic resonance imaging outcomes in the literature.
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Extreme Glycemic Fluctuations Debilitate NRG1, ErbB Receptors and Olig1 Function: Association with Regeneration, Cognition and Mood Alterations During Diabetes. Mol Neurobiol 2021; 58:4727-4744. [PMID: 34165684 DOI: 10.1007/s12035-021-02455-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 06/16/2021] [Indexed: 12/28/2022]
Abstract
Neuronal regeneration is crucial for maintaining intact neural interactions for perpetuation of cognitive and emotional functioning. The NRG1-ErbB receptor signaling is a key pathway for regeneration in adult brain and also associated with learning and mood stabilization by modulating synaptic transmission. Extreme glycemic stress is known to affect NRG1-ErbB-mediated regeneration in brain; yet, it remains unclear how the ErbB receptor subtypes are differentially affected due to such metabolic variations. Here, we assessed the alterations in NRG1, ErbB receptor subtypes to study the regenerative potential, both in rodents as well as in neuronal and glial cell models of hyperglycemia and hypoglycemic insults during hyperglycemia. The pro-oxidant and anti-oxidant status leading to degenerative changes in brain regions were determined. The spatial memory and anxiogenic behaviour of experimental rodents were tested using 'T' maze and Elevated Plus Maze. Our data revealed that the extreme glycemic discrepancies during diabetes and recurrent hypoglycemia lead to altered expression of NRG1, ErbB receptor subtypes, Syntaxin1 and Olig1 that shows association with impaired regeneration, synaptic dysfunction, demyelination, cognitive deficits and anxiety.
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Saado S, Bara A, Abdallah Y. Aicardi syndrome in a 7-month-old girl with tonic seizures and skeletal defects: A case report. Ann Med Surg (Lond) 2021; 66:102447. [PMID: 34136214 PMCID: PMC8181190 DOI: 10.1016/j.amsu.2021.102447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 05/20/2021] [Accepted: 05/23/2021] [Indexed: 11/28/2022] Open
Abstract
Introduction and importance: Aicardi syndrome (AS) is a rare genetic syndrome characterized by a triad of features: agenesis or hypogenesis of corpus callosum, chorioretinal lacunae, and infantile spasms, along with other neurodevelopmental, ocular, craniofacial, gastrointestinal, and musculoskeletal disorders. The precise etiology of AS is unknown, and establishing a diagnosis is challenging since it is an extremely rare syndrome and may mimic other congenital neurological defects. Case presentation A 2-month-old girl was brought to our hospital, she developed multiple episodes of generalized spasticity with hyperflexion of upper and lower extremities on trunk (tonic seizure), with fast jerking movements of the eye, with signs of Psychomotor Development delay. Clinical discussion Ophthalmic examination showed bilateral medial strabismus without nystagmus, Retinal examination showed bilateral small peripapillary well-circumscribed chorioretinal lacunae with hyperpigmented borders, thoracic spine x-ray (AP view) showed hemivertebrae and loss of height in the 7th and 8th thoracic vertebral body. Magnetic Resonance Imaging (MRI) revealed grey matter heterotopia, underdevelopment of the left operculum, hypogenesis of the corpus callosum, hypogenesis of inferior vermis, and multiple cysts with peripheral enhancing. Eventually, the diagnosis of AS is confirmed by the results of radiological imaging and ophthalmology exam. Conclusion In this paper, we report a case of Aicardi syndrome diagnosed in a 7-month-old girl with frequent tonic seizures. We report this case to highlight that Aicardi syndrome should be considered in the differential diagnosis in cases of frequent tonic seizures with abnormal findings on retinal examination and characteristic findings on MRI. Aicardi syndrome (AS) is a rare syndrome characterized by a triad of features. AS triad is callosal hypogenesis, chorioretinal lacunae, and infantile spasms. Establishing the diagnosis of AS is challenging. AS may mimic other congenital neurological defects.
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Yang J, Ma X, Li R, Ma X, Chen J, Zhang X. Reversible splenial lesion syndrome in sisters with sensorineural deafness as the first manifestation. Heliyon 2021; 7:e07057. [PMID: 34113728 PMCID: PMC8170165 DOI: 10.1016/j.heliyon.2021.e07057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 12/29/2020] [Accepted: 05/10/2021] [Indexed: 11/17/2022] Open
Abstract
Reversible splenial lesion syndrome (RESLES) is a rare clinico-radiological disorder syndrome with unclear pathophysiology. Here, two sisters with sensorineural deafness as the chief complaint diagnosed with RESLES was reported. Although the sisters had the disease successively, they were divided into two types on imaging by isolated lesions of splenium of the corpus callosum (SCC) and extensive lesions of the corpus callosum. The clinical manifestations and lesions on MRI disappeared after 6 months. The sensorineural deafness of the sisters in this article may be caused by transcallosal auditory pathway (TCAP) injury. Auditory handicap has been found in previous RESLES cases, indicating that we know little about the connection between the SCC and the auditory pathway, and further research is needed.
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Yalçınkaya BÇ, Ertürk Çetin Ö, Kılıç H, Demirci O, Çokyaman T, Uygunoğlu U. A rare presentation of Susac syndrome: Report of three pediatric cases. Mult Scler Relat Disord 2021; 53:103074. [PMID: 34139460 DOI: 10.1016/j.msard.2021.103074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/23/2021] [Accepted: 05/31/2021] [Indexed: 11/25/2022]
Abstract
Susac syndrome is a rare disorder that is clinically characterized by encephalopathy, retinopathy and hearing loss. Most of the reported cases in the literature are adult patients, pediatric presentation is extremely rare. Here we present three pediatric patients aged between 10-15; diagnosed as Susac syndrome. They all had thalamic involvement in addition to typical callosal lesions. All of the three patients had a monophasic course and good treatment response.
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Sadek MN, Ismail ES, Kamel AI, Saleh AA, Youssef AA, Madbouly NM. Diffusion tensor imaging of corpus callosum in adolescent females with borderline personality disorder. J Psychiatr Res 2021; 138:272-279. [PMID: 33872964 DOI: 10.1016/j.jpsychires.2021.04.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 04/05/2021] [Accepted: 04/08/2021] [Indexed: 02/06/2023]
Abstract
OBJECTIVES The aim of this study was to assess the structural alteration of corpus callosum (CC) in adolescent females with Borderline Personality Disorder (BPD) and detect the relationship between these changes and BPD symptoms. METHODS A comparative case control study was conducted on 50 adolescent females that were divided into 2 groups; 25 outpatients suffering from BPD (according to DSM-IV-TR diagnostic criteria) compared to 25 healthy adolescents. All subjects were assessed by Borderline Personality Questionnaire, Barratt impulsivity scale-11, Brief Non-Suicidal Self-Injury Assessment tool, Beck Scale for Suicidal Ideation, and Diffusion tensor imaging. RESULTS Relative to control subjects, BPD patients had significantly lower fractional anisotropy (FA) values in the genu and lower mean diffusivity (MD) values in the body of CC. There was a negative correlation between FA values in the genu and body of CC and impulsivity. MD in the body of CC was positively correlated with motor impulsiveness and negatively correlated with suicidality. CONCLUSION Adolescent females with BPD show structural alterations in the CC that are related to symptoms of emotional dysregulation and impulsivity.
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Morihara K, Kakinuma K, Kobayashi E, Kawakami N, Narita W, Kanno S, Tanaka F, Suzuki K. Improvement in callosal disconnection syndrome with recovery of callosal connectivity. Neurocase 2021; 27:323-331. [PMID: 34365896 DOI: 10.1080/13554794.2021.1959935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Recent advancements in radiological techniques have enabled the observation of the topographic distribution of the human corpus callosum. However, its functional connectivity remains to be elucidated. The symptoms of callosal disconnection syndrome (CDS) can potentially reveal the functional connections between the cerebral hemispheres. Herein, we report a patient with CDS, whose callosal lesion was restricted to the posterior midbody, isthmus, and an anterior part of the dorsal splenium. A 53-year-old right-handed woman demonstrated CDS following cerebral infarction associated with subarachnoid hemorrhage. She exhibited CDS including ideomotor apraxia, and tactile anomia with the left hand, cross-replication of hand postures, cross-localization of the fingers, and constructional impairment with the right hand. Six months after onset, the left-handed ideomotor apraxia on imitation improved, but that to command did not, which indicated the difference in the nature of the transcallosal connections between ideomotor apraxia on imitation and ideomotor apraxia to command. Longitudinal CDS observation and corpus callosum tractography will prove useful in expanding our understanding of the nature of the organization of interhemispheric information transference.
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138
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Kashiwagi M, Tanabe T, Oba C, Nomura S, Ashida A. Reversible splenial lesions during febrile illness with or without white matter lesions. Brain Dev 2021; 43:698-704. [PMID: 33715865 DOI: 10.1016/j.braindev.2021.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 02/05/2021] [Accepted: 02/15/2021] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Reversible splenium lesions during febrile illness (RESLEF) are found in a spectrum. There are two types of corpus callosum (CC) lesions: CC-only type, with limited lesions and the CC (+) type, with extensive white-matter lesions. This retrospective study aimed to describe the differences in clinical findings between CC-only and CC (+) lesions and the association between onset age and clinico-radiological features in RESLEF. METHODS Fifty-two episodes of CC-only or CC (+) lesions accompanied by neurological symptoms, e.g., seizures, delirious behavior (DB), and disturbance of consciousness (DC), from January 2008 to October 2019 were included. We analyzed the etiology (pathogen), clinical course, laboratory data, magnetic resonance imaging and electroencephalography findings, therapy, and prognosis. RESULTS The rate of DC in the CC (+) was significantly higher than that in the CC-only group (5/6 [83%] vs 7/46 [15%]; p = 0.0016). The median number of seizures in the CC (+) was also significantly higher than that in the CC-only group (4 [0-7] vs 0 [0-7]; p = 0.034). Further, in RESLEF, the median onset age (months) in the seizure was significantly lower than that in the no-seizure group (39 [12-74] vs 83 [28-174]; p = 0.0007). The median onset age (months) in the DB was significantly higher than that in the no-DB group (74.5 [26-174] vs 28 [12-139]; p = 0.003). CONCLUSIONS In RESLEF, CC (+) is a more severe neurological symptom than CC-only. Furthermore, the onset age is related to the type of neurological symptoms that appear.
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Lumaca M, Baggio G, Vuust P. White matter variability in auditory callosal pathways contributes to variation in the cultural transmission of auditory symbolic systems. Brain Struct Funct 2021; 226:1943-1959. [PMID: 34050791 DOI: 10.1007/s00429-021-02302-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 05/17/2021] [Indexed: 12/11/2022]
Abstract
The cultural transmission of spoken language and music relies on human capacities for encoding and recalling auditory patterns. In this experiment, we show that interindividual differences in this ability are associated with variation in the organization of cross-callosal white matter pathways. First, high-angular resolution diffusion MRI (dMRI) data were analyzed in a large participant sample (N = 51). Subsequently, these participants underwent a behavioral test that models in the laboratory the cultural transmission of auditory symbolic systems: the signaling game. Cross-callosal and intrahemispheric (arcuate fasciculus) pathways were reconstructed and analyzed using conventional diffusion tensor imaging (DTI) as well as a more advanced dMRI technique: fixel-based analysis (FBA). The DTI metric of fractional anisotropy (FA) in auditory callosal pathways predicted-weeks after scanning-the fidelity of transmission of an artificial tone system. The ability to coherently transmit auditory signals in one signaling game, irrespective of the signals learned during the previous game, was predicted by morphological properties of the fiber bundles in the most anterior portions of the corpus callosum. The current study is the first application of dMRI in the field of cultural transmission, and the first to connect individual characteristics of callosal pathways to core behaviors in the transmission of auditory symbolic systems.
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Shah A, Jhawar S, Goel A, Goel A. Corpus Callosum and Its Connections: A Fiber Dissection Study. World Neurosurg 2021; 151:e1024-e1035. [PMID: 34033953 DOI: 10.1016/j.wneu.2021.05.047] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/11/2021] [Accepted: 05/13/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVE We performed a fine white fiber dissection to demonstrate the extensive connections of the corpus callosum. MATERIAL AND METHODS Three formalin-fixed frozen cadaveric human brain specimens were dissected using Klingler's technique. On one half of each hemisphere, the superior connections of the corpus callosum were dissected and in the other half the inferior connections of the corpus callosum were dissected. RESULTS The mean length of the corpus callosum from the rostrum to the splenium was 7.8 cm. The fibers of the corpus callosum were classified as superior/dorsal radiations, inferior/ventral radiations, anterior radiations, and posterior radiations. The entire transverse length of the dorsal callosal radiation from one hemisphere to the other was 8.1 cm. For anterior interhemispheric approaches, an incision in the anterior part of the body not extending beyond 3.5 cm from the genu was found to be safe with regards to crossing motor fibers. CONCLUSIONS The corpus callosum was found to have intricate connections with all the lobes of the cerebral hemispheres, including the insular region and the limbic and paralimbic areas. Based on the course and traverse of the callosal fibers, a transverse incision in the corpus callosum should be preferred when performing a callosotomy to access intraventricular lesions as this splits the callosal fibers instead of transecting them. The analysis of the course of the callosal radiations enhances understanding of the growth pattern of primary corpus callosal gliomas and helps to design a safe surgical strategy.
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Mapping and anatomo-surgical techniques for SMA-cingulum- corpus callosum gliomas; how I do it. Acta Neurochir (Wien) 2021; 163:1239-1246. [PMID: 33779836 PMCID: PMC8053665 DOI: 10.1007/s00701-021-04774-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 02/16/2021] [Indexed: 11/13/2022]
Abstract
Background Awake brain mapping paradigms are variable, particularly in SMA, and not personalised to each patient. In addition, subpial resections do not offer full protection to vascular injury, as the pia can be easily violated. Methods Mapping paradigms developed by a multidisciplinary brain mapping team. During resection, a combined subpial/interhemispheric approach allowed early identification and arterial skeletonization. Precise anatomo-surgical dissection of the affected cingulum and corpus callosum was achieved. Conclusions In SMA-cingulum-CC tumours, a combined subpial/interhemispheric approach reduces risk of vascular injury allowing precise anatomo-surgical dissections. Knowledge of cognitive functions of affected parcels is likely to offer best outcomes. Supplementary Information The online version contains supplementary material available at 10.1007/s00701-021-04774-7.
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Functional and structural impairment of transcallosal motor fibres in ALS: a study using transcranial magnetic stimulation, diffusion tensor imaging, and diffusion weighted spectroscopy. Brain Imaging Behav 2021; 15:748-757. [PMID: 32306281 DOI: 10.1007/s11682-020-00282-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Imaging studies showed that the structure of the corpus callosum (CC) is affected in amyotrophic lateral sclerosis (ALS). Some clinical studies also suggest that interhemispheric connectivity is altered, since mirror movements seem to occur in ALS. Finally, reduced interhemispheric inhibition (IHI), studied by transcranial magnetic stimulation (TMS), has been reported. It is not known whether there is any association between these findings. Here, we studied the integrity of the CC in ALS on the morphological, the functional, the electrophysiological, and the clinical level. Twenty-seven right-handed ALS patients and 21 healthy right-handed controls were included. Mirror activity (MA) was quantified using surface EMG. Diffusion tensor imaging tractography was used to segment the CC and quantify fractional anisotropy (FA). We studied the diffusivity of the intra-axonal markers N-acetylaspartate+N-acetyl aspartyl glutamate D(tNAA) within the CC. IHI was studied as a marker of CC function using a double-pulse TMS protocol. ALS patients showed significantly decreased FA in the motor segment of the CC (p < 0.01), and IHI was significantly reduced compared to controls (p = 0.01). However, no differences were observed regarding D(tNAA) and MA. The morphological as well as the functional integrity of the CC are altered in ALS. IHI was reduced in ALS, associated with decreased FA in the motor CC. Patients did not exhibit increased MA. Also, no differences within the CC were observed using diffusion-weighted spectroscopy. IHI might serve as a marker of transcallosal pathway disruption in ALS, even before clinical deficits become apparent.
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A preliminary investigation of corpus callosum subregion white matter vulnerability and relation to chronic outcome in boxers. Brain Imaging Behav 2021; 14:772-786. [PMID: 30565025 DOI: 10.1007/s11682-018-0018-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Microstructural neuropathology occurs in the corpus callosum (CC) after repetitive sports concussion in boxers and can be dose-dependent. However, the specificity and relation of CC changes to boxing exposure extent and post-career psychiatric and neuropsychological outcomes are largely unknown. Using deterministic diffusion tensor imaging (DTI) techniques, boxers and demographically-matched, noncontact sport athletes were compared to address literature gaps. Ten boxers and 9 comparison athletes between 26 and 59 years old (M = 44.63, SD = 9.24) completed neuropsychological testing and MRI. Quantitative DTI metrics were estimated for CC subregions. Group×Region interaction effects were observed on fractional anisotropy (FA; η2p ≥ .21). Follow-up indicated large effects of group (η2p ≥ .26) on splenium FA (boxers<comparisons) and genu mean diffusivity (MD; boxers>comparisons), but not radial diffusivity (RD). The group of boxers had moderately elevated number of psychiatric symptoms and reduced neuropsychological scores relative to the comparison group. In boxers, years sparring, professional bouts, and knockout history correlated strongly (r > |.40|) with DTI metrics and fine motor dexterity. In the comparison group, splenium FA correlated positively with psychiatric symptoms. In the boxer group, neuropsychological scores correlated with DTI metrics in all CC subregions. Results suggested relative vulnerability of the splenium and, to a lesser extent, the genu to chronic, repetitive head injury from boxing. Dose-dependent associations of professional boxing history extent with DTI white matter structure indices as well as fine motor dexterity were supported. Results indicated that symptoms of depression and executive dysfunction may provide the strongest indicators of global CC disruption from boxing.
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Prigge MBD, Lange N, Bigler ED, King JB, Dean DC, Adluru N, Alexander AL, Lainhart JE, Zielinski BA. A 16-year study of longitudinal volumetric brain development in males with autism. Neuroimage 2021; 236:118067. [PMID: 33878377 PMCID: PMC8489006 DOI: 10.1016/j.neuroimage.2021.118067] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 03/24/2021] [Accepted: 04/12/2021] [Indexed: 12/16/2022] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder with unknown brain etiology. Our knowledge to date about structural brain development across the lifespan in ASD comes mainly from cross-sectional studies, thereby limiting our understanding of true age effects within individuals with the disorder that can only be gained through longitudinal research. The present study describes FreeSurfer-derived volumetric findings from a longitudinal dataset consisting of 607 T1-weighted magnetic resonance imaging (MRI) scans collected from 105 male individuals with ASD (349 MRIs) and 125 typically developing male controls (258 MRIs). Participants were six to forty-five years of age at their first scan, and were scanned up to 5 times over a period of 16 years (average inter-scan interval of 3.7 years). Atypical age-related volumetric trajectories in ASD included enlarged gray matter volume in early childhood that approached levels of the control group by late childhood, an age-related increase in ventricle volume resulting in enlarged ventricles by early adulthood and reduced corpus callosum age-related volumetric increase resulting in smaller corpus callosum volume in adulthood. Larger corpus callosum volume was related to a lower (better) ADOS score at the most recent study visit for the participants with ASD. These longitudinal findings expand our knowledge of volumetric brain-based abnormalities in males with ASD, and highlight the need to continue to examine brain structure across the lifespan and well into adulthood.
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Corpus Callosum Remodeling in Glioma: Constancy of Fiber Density and Anisotropy in MRI. Can J Neurol Sci 2021; 49:282-286. [PMID: 33845935 DOI: 10.1017/cjn.2021.64] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Corpus callosum (CC) is the primary fiber system bridging the cerebral hemispheres and is of critical importance for glioma migration which downgrades the prognosis. Here we present the specific pattern of CC restructuring in glioma patients. We probe that the magnetic resonance imaging-based fiber count decrease can be a ready noninvasive indicator of glioma aggressivity and prognosis. We find that to maintain the callosal neural transmission efficiency, the optimum architectural density of white matter fibers remains unchanged, even though there is gross fiber loss. This adaptation occurs by CC's isotonic restructuration, a protective compensatory behavior for maintaining CC's optimal functional efficiency despite malignant infiltration.
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Dosi C, Pasquariello R, Ticci C, Astrea G, Trovato R, Rubegni A, Tessa A, Cioni G, Santorelli FM, Battini R. Neuroimaging patterns in paediatric onset hereditary spastic paraplegias. J Neurol Sci 2021; 425:117441. [PMID: 33866115 DOI: 10.1016/j.jns.2021.117441] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 03/06/2021] [Accepted: 04/05/2021] [Indexed: 11/26/2022]
Abstract
Hereditary spastic paraplegias (HSPs) are a clinically and genetically heterogeneous group of neurodegenerative disorders characterized by progressive spasticity and weakness of the lower limbs with a notable phenotypic variation and an autosomal recessive (AR), autosomal dominant (AD), and X-linked inheritance pattern. The recent clinical use of next generation sequencing methods has facilitated the diagnostic approach to HSPs, but the diagnosis remains quite challenging considering its wide clinical and genetic heterogeneity. In this scenario, magnetic resonance imaging (MRI) emerges as a valuable tool in helping to exclude mimicking disorders and to guide genetic testing. The aim of this study is to investigate the presence of possible patterns of morphostructural MRI findings that may provide relevant clues for a specific genetic HSP subtype. In our cohort, for example, white matter abnormalities were the most common finding followed by the thinning of the corpus callosum, which, interestingly, presented different thinning characteristics depending on the HSP subtype.
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Albakr A, Sader N, Lama S, Sutherland GR. Interhemispheric arachnoid cyst. Surg Neurol Int 2021; 12:125. [PMID: 33880230 PMCID: PMC8053473 DOI: 10.25259/sni_660_2020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 02/24/2021] [Indexed: 11/04/2022] Open
Abstract
Background Interhemispheric arachnoid cysts are uncommon and typically associated with other midline neurodevelopmental disorders, such as complete or partial agenesis of the corpus callosum. Case Description We report a case of a 27-year-old woman with worsening headache, memory deficit, and radiological progression of an interhemispheric arachnoid cyst. The treatment consisted of craniotomy for interhemispheric cyst fenestration into both the interhemispheric cistern and lateral ventricle. The postoperative course was unremarkable, with considerable clinical improvement and significant reduction in cyst size. Conclusion We successfully treat a patient with an enlarging arachnoid cyst and associated progressive symptoms with microsurgical fenestration.
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Moteki Y, Kobayashi T, Kawamata T. Clinical Significance of Cytotoxic Lesions of the Corpus Callosum in Subarachnoid Hemorrhage Patients: A Retrospective Analysis. Cerebrovasc Dis 2021; 50:405-411. [PMID: 33774621 DOI: 10.1159/000514383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 01/07/2021] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Cytotoxic lesions of the corpus callosum are secondary lesions induced by significant increases in cytokine levels in the brain and are associated with subarachnoid hemorrhage (SAH). However, their clinical significance in SAH patients remains unclear. METHODS We retrospectively analyzed SAH patients who were treated in our hospital and evaluated between-group differences in the backgrounds, clinical findings, and outcomes between SAH patients who developed cytotoxic lesions of the corpus callosum and those who did not. We further compared patients who achieved good outcomes with those who had poor outcomes. Multivariate logistic regression analysis was used to identify risk factors for poor clinical outcomes. RESULTS We analyzed 159 SAH patients; 17 patients (10.7%) had cytotoxic lesions of the corpus callosum. Patients with cytotoxic lesions of the corpus callosum were more likely to be in a severe condition (World Federation of Neurosurgical Societies grading IV-V: odds ratio [OR], 4.53; 95% confidence interval [95% CI]: 1.60-12.84; p = 0.0042) and have an intraventricular (OR, 5.98; 95% CI: 1.32-27.13; p = 0.0054) or an intraparenchymal hematoma (OR, 3.62; 95% CI: 1.25-10.45; p = 0.023). Patients with cytotoxic lesions of the corpus callosum had a greater propensity of a poor outcome 3 months after onset (modified Rankin Scale score 0-2: OR, 0.22; 95% CI: 0.07-0.66; p = 0.0043). Multivariate analysis confirmed that cytotoxic lesions of the corpus callosum increased the risk of a poor outcome (OR, 4.39; 95% CI: 1.06-18.1; p = 0.037). DISCUSSION/CONCLUSIONS The development of cytotoxic lesions of the corpus callosum may be related to the extent of hematomas in SAH patients. Although they are usually reversible lesions, the development of cytotoxic lesions of the corpus callosum may be a predictor of poor outcomes in SAH patients.
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Social Inferences in Agenesis of the Corpus Callosum and Autism: Semantic Analysis and Topic Modeling. J Autism Dev Disord 2021; 52:569-583. [PMID: 33768420 DOI: 10.1007/s10803-021-04957-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2021] [Indexed: 10/21/2022]
Abstract
Impoverished capacity for social inference is one of several symptoms that are common to both agenesis of the corpus callosum (AgCC) and Autism Spectrum Disorder (ASD). This research compared the ability of 14 adults with AgCC, 13 high-functioning adults with ASD and 14 neurotypical controls to accurately attribute social meaning to the interactions of animated triangles. Descriptions of the animations were analyzed in three ways: subjective ratings, Linguistic Inquiry and Word Count, and topic modeling (Latent Dirichlet Allocation). Although subjective ratings indicated that all groups made similar inferences from the animations, the index of perplexity (atypicality of topic) generated from topic modeling revealed that inferences from individuals with AgCC or ASD displayed significantly less social imagination than those of controls.
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Corpus callosum morphology across the lifespan in baboons (Papio anubis): A cross-sectional study of relative mid-sagittal surface area and thickness. Neurosci Res 2021; 171:19-26. [PMID: 33744333 DOI: 10.1016/j.neures.2021.03.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 02/23/2021] [Accepted: 03/11/2021] [Indexed: 11/22/2022]
Abstract
The corpus callosum enables integration and coordination of cognitive processing between the cerebral hemispheres. In the aging human brain, these functions are affected by progressive axon and myelin deteriorations, reflected as atrophy of the midsagittal corpus callosum in old age. In non-human primates, these degenerative processes are less pronounced as previous morphometric studies on capuchin monkey, rhesus monkeys, and chimpanzees do not find old-age callosal atrophy. In the present study, we extend these previous findings by studying callosal development of the olive baboon (Papio anubis) across the lifespan and compare it to chimpanzee and human data. For this purpose, total relative (to forebrain volume) midsagittal area, subsectional area, and regional thickness of the corpus callosum were assessed in 91 male and female baboons using non-invasive MRI-based morphometry. The studied age range was 2.5-26.6 years and lifespan trajectories were fitted using general additive modelling. Relative area of the total and anterior corpus callosum showed a positive linear trajectory. That is, both measures increased slowly but continuously from childhood into old age, and no decline was observed in old age. Thus, comparable with all other non-human primates studied to-date, baboons do not show callosal atrophy in old age. This observation lends supports to the notion that atrophy of the corpus callosum is a unique characteristic of human brain aging.
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