AIM:To evaluate the predictive value of superficial retinal capillary plexus(SRCP)and radial peripapillary capillary(RPC)for visual field recovery after optic cross decompression and compare them with peripapillary ne...AIM:To evaluate the predictive value of superficial retinal capillary plexus(SRCP)and radial peripapillary capillary(RPC)for visual field recovery after optic cross decompression and compare them with peripapillary nerve fiber layer(pRNFL)and ganglion cell complex(GCC).METHODS:This prospective longitudinal observational study included patients with chiasmal compression due to sellar region mass scheduled for decompressive surgery.Generalized estimating equations were used to compare retinal vessel density and retinal layer thickness preand post-operatively and with healthy controls.Logistic regression models were used to assess the relationship between preoperative GCC,pRNFL,SRCP,and RPC parameters and visual field recovery after surgery.RESULTS:The study included 43 eyes of 24 patients and 48 eyes of 24 healthy controls.Preoperative RPC and SRCP vessel density and pRNFL and GCC thickness were lower than healthy controls and higher than postoperative values.The best predictive GCC and pRNFL models were based on the superior GCC[area under the curve(AUC)=0.866]and the tempo-inferior pRNFL(AUC=0.824),and the best predictive SRCP and RPC models were based on the nasal SRCP(AUC=0.718)and tempo-inferior RPC(AUC=0.825).There was no statistical difference in the predictive value of the superior GCC,tempo-inferior pRNFL,and tempo-inferior RPC(all P>0.05).CONCLUSION:Compression of the optic chiasm by tumors in the saddle area can reduce retinal thickness and blood perfusion.This reduction persists despite the recovery of the visual field after decompression surgery.GCC,pRNFL,and RPC can be used as sensitive predictors of visual field recovery after decompression surgery.展开更多
Objective: By means of neuropsychologic tests, to further analyse a specific chiasmal monocular visual testing behaviour, here labelled temporal blocking because of the elective ignorance of optotypes on the temporal ...Objective: By means of neuropsychologic tests, to further analyse a specific chiasmal monocular visual testing behaviour, here labelled temporal blocking because of the elective ignorance of optotypes on the temporal side of the chart. Often it is combined with impairment of reading and other cognitive impairments. Methods: Eighteen patients with lesions to the chiasm and some degree of temporal blocking aged 24 - 76 years underwent: 1) tests for visual neglect (Gothenburg test;behavioural inattention tests: star cancellation;line bisection);2) visuo-perceptual tests;and 3) a test involving reading a crowded ten-letter and cipher bar. Results: The temporal blocking in two patients recovered after emergency neurosurgery and their results were normal when subsequently tested. Of the 16 patients with deficiencies, 14 had a poorer left eye (p Conclusions: The best neuropsychologic tests appeared to be those for visual neglect and the crowded bar test. In most cases, the right cerebral hemisphere’s lack of some crossed information from the left eye, usually needed for normative saccades and adjustment to visual space, may be a factor underlying the specific visual behaviour.展开更多
Background: In a previous study, a specific visual behaviour was described in four chiasmal patients. It manifested as inattention/ignorance within the temporal visual space (“visual blocking”) at monocular visual a...Background: In a previous study, a specific visual behaviour was described in four chiasmal patients. It manifested as inattention/ignorance within the temporal visual space (“visual blocking”) at monocular visual acuity testing. Moreover, in 3 out of the 4, the process of reading a text appeared cognitively impaired. Methods: As a supplement to conventional visual field testing, the present analysis focus was on microperimetry by Scanning Laser Ophthalmocopy (SLO). Our aim was to identify the perceptual retinal counterparts to the temporally located visual field defects as caused by the visual pathway lesion on a chiasmal level, possibly also to indicate the apparently ineffective saccadic movements underlying that only part of the line on the chart could be given. Results and Conclusions: The central retinal areas with lacking recognition by SLO testing were given by black rectangles expressing scotomatous points;they clustered in a zone extending nasally from the fixation area, as expected. The methodology further depicted an orderly fixation in two cases, and only minor deviation in two. Fixation saccades thus were considered by and large within normal and with only exceptional outlier points recorded. All considered, the shortcomings of the perceptual mechanisms underlying the lateralised visual inattention as observed in the four patients have remained without a satisfactory explanation.展开更多
This paper is an attempt to ascertain the role of the optical coherence tomography by measuring the retinal nerve fiber layer thickness and ganglion cell complex area to predict postoperative visual outcome after chia...This paper is an attempt to ascertain the role of the optical coherence tomography by measuring the retinal nerve fiber layer thickness and ganglion cell complex area to predict postoperative visual outcome after chiasmal decompression. 16 eyes scheduled for chiasmal decompression surgery were assessed before and 3 months after surgery with standard automated perimetry and OCT (optical coherence tomography). Preoperative RNFL (retinal nerve fibre layer) thickness and GCC (ganglion cell complex) area were compared with 20 normal control eyes. 13 cases were operated by microscopic assisted endoscopic endonasal transsphenoidal approach;the remaining 3 cases were operated transcranially. Spearman’s correlation analysis was used to evaluate the relationship between preoperative RNFL thickness, GCC area, postoperative mean deviation and temporal visual field sensitivity (1/Lambert). Preoperative measurements of RNFL thickness and all GCC area were significantly reduced in the patients compared with normal control. 3 months postoperative evaluation showed improvement of the visual field, but reduction in global and sectorial RNFL thickness except for nasal sector. Moreover, absolute postoperative (not pre-post change) visual field parameters were significantly correlated to preoperative RNFL (P = 0.00399 for mean deviation, P = 0.0023 for temporal sensitivity), GCC thickness (P = 0.00736 for mean deviation, P = 0.0469 for temporal sensitivity), with FLV (focal loss value) (P = 0.0012 for mean deviation, P = 0.0021 for temporal sensitivity) showed a higher correlation. Reduced RNFL thickness mainly, and GCC area minimally, were associated with the worst visual field outcome. FLV is a new prognostic value.展开更多
This paper traces the genealogy of reversibility,chiasma,and chiasme in Merleau-Ponty's writings and offers a new characterisation of his later ontology in terms of a multi-layered chiasme-focused topology informe...This paper traces the genealogy of reversibility,chiasma,and chiasme in Merleau-Ponty's writings and offers a new characterisation of his later ontology in terms of a multi-layered chiasme-focused topology informed by subtle differences and interconnections among these notions.We need to grasp the significance of reversibility not only in terms of constant recoil and impossible overlap but also of its situatedness in the crisscrossing between Dasein and things,and between the inside/invisible and the outside/visible."Chiasma" was initially introduced as a reference to the intersection of perspectives.Merleau-Ponty deploys it to articulate macroscopic insights concerning the nature of philosophy and the interweaving connections between self,other,and the world.In comparison,"reversibility" is primarily used to describe the microscopic bond between touching-touched and perceiving-perceived.I argue that,as Merleau-Ponty's ultimate choice of wording,"chiasme" incorporated the significance of both "reversibility" and "chiasma." A chiasme-focused topology that retains the significance of all three of the terms would serve to better convey the import of Merleau-Ponty's later ontology,which aims to dissolve and to re-configure our conceptions about being,body,self,and the other from within and from below.展开更多
Gregory Bateson is famous for his description of the ＂double bind＂ that occurs when human （and animal） communication interaction becomes dysfunctional/-/is principal example is the ＂nip versus bite＂ opposition t...Gregory Bateson is famous for his description of the ＂double bind＂ that occurs when human （and animal） communication interaction becomes dysfunctional/-/is principal example is the ＂nip versus bite＂ opposition that he observed when a human and a dog （or two monkies） ＂play＂ （nip） and then play turns to ＂work＂ （bite）.The model is a semiotic failure by not accounting for negation, i.e., ＂labor＂ （not-nip） and ＂leisure＂ （not-bite）. Thus, if there is a double bind, there must be a foundational apposition condition of single-bind （functional communication） in the system, i.e., the possibility of an actual choice, which logically entails a not-choice [potential ＂new＂ choice]. The play/work versus leisure/labor distinction by combination goes back at least to Plato, and in modernity to Ernst Cassirer and Karl Buhler, but has its most strategic communicological development in Maurice Merleau-Ponty＇s tropic logic thesis on Chiasm. The thesis is better known through its application by Roman Jakobson and Claude L6vi-Strauss as a tropic logic of metaphor （attribute--substance quality） and metonymy （part--whole quantity）. My analysis illustrates the tropic logic by contrasting a fundamental metaphysical thesis that Being/Having （Play--Work） and Becoming/Doing （Leisure--Labor） must be phenomenological （tropic） as a basis for Semiotics （logic）. Thus in Communicology, Play is a ＂pretend reality＂ of actual agency, and, Playing is a ＂pretended action in Play＂ of symbolic agency.展开更多
The mechanism of bitemporal hemianopia arising as a result of chiasmal compression is unknown.In this study,we combined an ex vivo experiment and finite element modelling(FEM)to investigate its potential mechanism.A c...The mechanism of bitemporal hemianopia arising as a result of chiasmal compression is unknown.In this study,we combined an ex vivo experiment and finite element modelling(FEM)to investigate its potential mechanism.A cadaveric human optic chiasm was scanned using micro-CT before and after deformation by inflation of Foley catheter,to simulate tumour growth from beneath.The geometry of the same chiasm was reconstructed and simulated using finite element analysis.Chiasmal deformations were extracted from the simulation and compared with those observed during micro-CT scanning.In addition,nerve fibre models examining variation in local fibre distribution patterns of the chiasm were incorporated to investigate the strain(deformation)distributions of the chiasm at an axonal level.The FEM model matched the micro-CT scans well both qualitatively and quantitatively.Compression of the chiasm induced high strains in the paracentral portions of the chiasm where the crossing optic nerve fibres are located.At an axonal level,the magnitude of strains affecting crossed fibres were greater than those affecting uncrossed fibres.The high strains in the paracentral portions of the chiasm,combined with the differences in strain between crossed and uncrossed nerve fibres,are consistent with a biomechanical explanation for the pattern of visual field loss seen in chiasmal compression.展开更多
The French discourse model of human communication is largely an engagement of the problematic concept of enlightenment as a product of the ability to reason by thinking.The engagement as speaking and writing becomes t...The French discourse model of human communication is largely an engagement of the problematic concept of enlightenment as a product of the ability to reason by thinking.The engagement as speaking and writing becomes thematic,when one considers that,the product called“reason”also should explicate the process wherein the conscious experience of being is essentially“reasonable”in doing as listening and reading.The engaged analysis of reason differentiates among parole,discours,langue,and langage as a synthesis of logic mediating rhetoric and grammar as models of expression and perception.The method is known as the trivium in the Medieval universities of Europe,subsequently adopted as a pedagogy throughout Europe,and last,adopted by C.S.Peirce as a foundational semiotic methodology for science(methodeutic).The influence of the human science adaptations emerges in France with the philosophic cross-over and intertwined(chiasm)positions of Existentialism,Phenomenology,Structuralism,and Semiology.Doing the reasonable requires metaphor and metonymy,simile and synecdoche in the service of expression,yet,it also demands the perception of their respective counterparts in allegory,analogy,allegoresis,and aphorism.The human journey from thinking to speaking to doing and the return(renvoi)is one of ingenuity made eloquent in the face of crisis.It was so for the Ionian enlightenment,it was so for the European enlightenment,and it is so for us.展开更多
Primary sellar atypical teratoid/rhabdoid tumor(AT/RT)is the most aggressive sellar mass.Although rare,sellar AT/RT exhibits a very relentless clinical course and usually results in death within months to a few years ...Primary sellar atypical teratoid/rhabdoid tumor(AT/RT)is the most aggressive sellar mass.Although rare,sellar AT/RT exhibits a very relentless clinical course and usually results in death within months to a few years after diagnosis.The best clinical evidence suggests that surgical debulking and timely adjuvant chemoradiation are most effective in prolonging survival.A preoperative radiological diagnosis of sellar AT/RT thus is crucial in informing patients and physicians about this devastating disease.This minireview summaries the imaging features of sellar AT/RT.magnetic resonance imaging features of sellar AT/RT and the much more common sellar mass,pituitary macroadenoma,are similar in most aspects:They are both isointense to brain gray matter on T1 and T2 imaging and enhance upon gadolinium administration.Suprasellar extension and cavernous sinus invasion are present in practically all cases of sellar AT/RT,but are also present in 50%-75%of pituitary macroadenomas,especially in large ones,suggesting that suprasellar extension and cavernous sinus invasion disproportionate to the tumor size may favor sellar AT/RT diagnosis.Since sellar AT/RT grows very rapidly and does not allow significant remodeling of perisellar structures,the imaging features of perisellar structures such as optic chiasm and cavernous sinus may be key for imaging diagnosis of sellar AT/RT although they have not been well described in sellar AT/RT.In limited cases of sellar AT/RT,optic chiasm degeneration and thinning,which are very common in pituitary macroadenoma,are not present,giving hope for using features of perisellar structures to diagnose sellar AT/RT by imaging.展开更多
文摘AIM:To evaluate the predictive value of superficial retinal capillary plexus(SRCP)and radial peripapillary capillary(RPC)for visual field recovery after optic cross decompression and compare them with peripapillary nerve fiber layer(pRNFL)and ganglion cell complex(GCC).METHODS:This prospective longitudinal observational study included patients with chiasmal compression due to sellar region mass scheduled for decompressive surgery.Generalized estimating equations were used to compare retinal vessel density and retinal layer thickness preand post-operatively and with healthy controls.Logistic regression models were used to assess the relationship between preoperative GCC,pRNFL,SRCP,and RPC parameters and visual field recovery after surgery.RESULTS:The study included 43 eyes of 24 patients and 48 eyes of 24 healthy controls.Preoperative RPC and SRCP vessel density and pRNFL and GCC thickness were lower than healthy controls and higher than postoperative values.The best predictive GCC and pRNFL models were based on the superior GCC[area under the curve(AUC)=0.866]and the tempo-inferior pRNFL(AUC=0.824),and the best predictive SRCP and RPC models were based on the nasal SRCP(AUC=0.718)and tempo-inferior RPC(AUC=0.825).There was no statistical difference in the predictive value of the superior GCC,tempo-inferior pRNFL,and tempo-inferior RPC(all P>0.05).CONCLUSION:Compression of the optic chiasm by tumors in the saddle area can reduce retinal thickness and blood perfusion.This reduction persists despite the recovery of the visual field after decompression surgery.GCC,pRNFL,and RPC can be used as sensitive predictors of visual field recovery after decompression surgery.
文摘Objective: By means of neuropsychologic tests, to further analyse a specific chiasmal monocular visual testing behaviour, here labelled temporal blocking because of the elective ignorance of optotypes on the temporal side of the chart. Often it is combined with impairment of reading and other cognitive impairments. Methods: Eighteen patients with lesions to the chiasm and some degree of temporal blocking aged 24 - 76 years underwent: 1) tests for visual neglect (Gothenburg test;behavioural inattention tests: star cancellation;line bisection);2) visuo-perceptual tests;and 3) a test involving reading a crowded ten-letter and cipher bar. Results: The temporal blocking in two patients recovered after emergency neurosurgery and their results were normal when subsequently tested. Of the 16 patients with deficiencies, 14 had a poorer left eye (p Conclusions: The best neuropsychologic tests appeared to be those for visual neglect and the crowded bar test. In most cases, the right cerebral hemisphere’s lack of some crossed information from the left eye, usually needed for normative saccades and adjustment to visual space, may be a factor underlying the specific visual behaviour.
文摘Background: In a previous study, a specific visual behaviour was described in four chiasmal patients. It manifested as inattention/ignorance within the temporal visual space (“visual blocking”) at monocular visual acuity testing. Moreover, in 3 out of the 4, the process of reading a text appeared cognitively impaired. Methods: As a supplement to conventional visual field testing, the present analysis focus was on microperimetry by Scanning Laser Ophthalmocopy (SLO). Our aim was to identify the perceptual retinal counterparts to the temporally located visual field defects as caused by the visual pathway lesion on a chiasmal level, possibly also to indicate the apparently ineffective saccadic movements underlying that only part of the line on the chart could be given. Results and Conclusions: The central retinal areas with lacking recognition by SLO testing were given by black rectangles expressing scotomatous points;they clustered in a zone extending nasally from the fixation area, as expected. The methodology further depicted an orderly fixation in two cases, and only minor deviation in two. Fixation saccades thus were considered by and large within normal and with only exceptional outlier points recorded. All considered, the shortcomings of the perceptual mechanisms underlying the lateralised visual inattention as observed in the four patients have remained without a satisfactory explanation.
文摘This paper is an attempt to ascertain the role of the optical coherence tomography by measuring the retinal nerve fiber layer thickness and ganglion cell complex area to predict postoperative visual outcome after chiasmal decompression. 16 eyes scheduled for chiasmal decompression surgery were assessed before and 3 months after surgery with standard automated perimetry and OCT (optical coherence tomography). Preoperative RNFL (retinal nerve fibre layer) thickness and GCC (ganglion cell complex) area were compared with 20 normal control eyes. 13 cases were operated by microscopic assisted endoscopic endonasal transsphenoidal approach;the remaining 3 cases were operated transcranially. Spearman’s correlation analysis was used to evaluate the relationship between preoperative RNFL thickness, GCC area, postoperative mean deviation and temporal visual field sensitivity (1/Lambert). Preoperative measurements of RNFL thickness and all GCC area were significantly reduced in the patients compared with normal control. 3 months postoperative evaluation showed improvement of the visual field, but reduction in global and sectorial RNFL thickness except for nasal sector. Moreover, absolute postoperative (not pre-post change) visual field parameters were significantly correlated to preoperative RNFL (P = 0.00399 for mean deviation, P = 0.0023 for temporal sensitivity), GCC thickness (P = 0.00736 for mean deviation, P = 0.0469 for temporal sensitivity), with FLV (focal loss value) (P = 0.0012 for mean deviation, P = 0.0021 for temporal sensitivity) showed a higher correlation. Reduced RNFL thickness mainly, and GCC area minimally, were associated with the worst visual field outcome. FLV is a new prognostic value.
文摘This paper traces the genealogy of reversibility,chiasma,and chiasme in Merleau-Ponty's writings and offers a new characterisation of his later ontology in terms of a multi-layered chiasme-focused topology informed by subtle differences and interconnections among these notions.We need to grasp the significance of reversibility not only in terms of constant recoil and impossible overlap but also of its situatedness in the crisscrossing between Dasein and things,and between the inside/invisible and the outside/visible."Chiasma" was initially introduced as a reference to the intersection of perspectives.Merleau-Ponty deploys it to articulate macroscopic insights concerning the nature of philosophy and the interweaving connections between self,other,and the world.In comparison,"reversibility" is primarily used to describe the microscopic bond between touching-touched and perceiving-perceived.I argue that,as Merleau-Ponty's ultimate choice of wording,"chiasme" incorporated the significance of both "reversibility" and "chiasma." A chiasme-focused topology that retains the significance of all three of the terms would serve to better convey the import of Merleau-Ponty's later ontology,which aims to dissolve and to re-configure our conceptions about being,body,self,and the other from within and from below.
文摘Gregory Bateson is famous for his description of the ＂double bind＂ that occurs when human （and animal） communication interaction becomes dysfunctional/-/is principal example is the ＂nip versus bite＂ opposition that he observed when a human and a dog （or two monkies） ＂play＂ （nip） and then play turns to ＂work＂ （bite）.The model is a semiotic failure by not accounting for negation, i.e., ＂labor＂ （not-nip） and ＂leisure＂ （not-bite）. Thus, if there is a double bind, there must be a foundational apposition condition of single-bind （functional communication） in the system, i.e., the possibility of an actual choice, which logically entails a not-choice [potential ＂new＂ choice]. The play/work versus leisure/labor distinction by combination goes back at least to Plato, and in modernity to Ernst Cassirer and Karl Buhler, but has its most strategic communicological development in Maurice Merleau-Ponty＇s tropic logic thesis on Chiasm. The thesis is better known through its application by Roman Jakobson and Claude L6vi-Strauss as a tropic logic of metaphor （attribute--substance quality） and metonymy （part--whole quantity）. My analysis illustrates the tropic logic by contrasting a fundamental metaphysical thesis that Being/Having （Play--Work） and Becoming/Doing （Leisure--Labor） must be phenomenological （tropic） as a basis for Semiotics （logic）. Thus in Communicology, Play is a ＂pretend reality＂ of actual agency, and, Playing is a ＂pretended action in Play＂ of symbolic agency.
基金Supported by National Natural Science Foundation of China(12002025)This study was approved by the ACT Health Human Research Ethics Committee(ETH 1.14.020).
文摘The mechanism of bitemporal hemianopia arising as a result of chiasmal compression is unknown.In this study,we combined an ex vivo experiment and finite element modelling(FEM)to investigate its potential mechanism.A cadaveric human optic chiasm was scanned using micro-CT before and after deformation by inflation of Foley catheter,to simulate tumour growth from beneath.The geometry of the same chiasm was reconstructed and simulated using finite element analysis.Chiasmal deformations were extracted from the simulation and compared with those observed during micro-CT scanning.In addition,nerve fibre models examining variation in local fibre distribution patterns of the chiasm were incorporated to investigate the strain(deformation)distributions of the chiasm at an axonal level.The FEM model matched the micro-CT scans well both qualitatively and quantitatively.Compression of the chiasm induced high strains in the paracentral portions of the chiasm where the crossing optic nerve fibres are located.At an axonal level,the magnitude of strains affecting crossed fibres were greater than those affecting uncrossed fibres.The high strains in the paracentral portions of the chiasm,combined with the differences in strain between crossed and uncrossed nerve fibres,are consistent with a biomechanical explanation for the pattern of visual field loss seen in chiasmal compression.
文摘The French discourse model of human communication is largely an engagement of the problematic concept of enlightenment as a product of the ability to reason by thinking.The engagement as speaking and writing becomes thematic,when one considers that,the product called“reason”also should explicate the process wherein the conscious experience of being is essentially“reasonable”in doing as listening and reading.The engaged analysis of reason differentiates among parole,discours,langue,and langage as a synthesis of logic mediating rhetoric and grammar as models of expression and perception.The method is known as the trivium in the Medieval universities of Europe,subsequently adopted as a pedagogy throughout Europe,and last,adopted by C.S.Peirce as a foundational semiotic methodology for science(methodeutic).The influence of the human science adaptations emerges in France with the philosophic cross-over and intertwined(chiasm)positions of Existentialism,Phenomenology,Structuralism,and Semiology.Doing the reasonable requires metaphor and metonymy,simile and synecdoche in the service of expression,yet,it also demands the perception of their respective counterparts in allegory,analogy,allegoresis,and aphorism.The human journey from thinking to speaking to doing and the return(renvoi)is one of ingenuity made eloquent in the face of crisis.It was so for the Ionian enlightenment,it was so for the European enlightenment,and it is so for us.
文摘Primary sellar atypical teratoid/rhabdoid tumor(AT/RT)is the most aggressive sellar mass.Although rare,sellar AT/RT exhibits a very relentless clinical course and usually results in death within months to a few years after diagnosis.The best clinical evidence suggests that surgical debulking and timely adjuvant chemoradiation are most effective in prolonging survival.A preoperative radiological diagnosis of sellar AT/RT thus is crucial in informing patients and physicians about this devastating disease.This minireview summaries the imaging features of sellar AT/RT.magnetic resonance imaging features of sellar AT/RT and the much more common sellar mass,pituitary macroadenoma,are similar in most aspects:They are both isointense to brain gray matter on T1 and T2 imaging and enhance upon gadolinium administration.Suprasellar extension and cavernous sinus invasion are present in practically all cases of sellar AT/RT,but are also present in 50%-75%of pituitary macroadenomas,especially in large ones,suggesting that suprasellar extension and cavernous sinus invasion disproportionate to the tumor size may favor sellar AT/RT diagnosis.Since sellar AT/RT grows very rapidly and does not allow significant remodeling of perisellar structures,the imaging features of perisellar structures such as optic chiasm and cavernous sinus may be key for imaging diagnosis of sellar AT/RT although they have not been well described in sellar AT/RT.In limited cases of sellar AT/RT,optic chiasm degeneration and thinning,which are very common in pituitary macroadenoma,are not present,giving hope for using features of perisellar structures to diagnose sellar AT/RT by imaging.
