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Background Crossed aphasia (CA) refers to aphasia following a right-hemispheric lesion in right-handed individuals. It has been suggested that the prevalence of CA differs with language, although its worldwide incidence, as reported by most studies, is less than 3%. Objective To find the incidence of CA in the Bengali language. Methods From 2016 to 2018, in a hospital located in a Bengali-speaking area of eastern India, 515 cases of first-ever stroke were documented, out of which 208 patients presented with aphasia (40.38%) according to their scores on the Bengali version of the Western Aphasia Battery. Results Among the patients with aphasia, 14 (6.73%; 8 men and 6 women) presented with CA. Of these, 10 were diagnosed with Broca aphasia and four with transcortical motor aphasia. No patient presented with Wernicke aphasia. Conclusions The relatively high incidence of CA in our study suggests that bi-hemispheric language representation may be more prevalent in Bengali speakers than in speakers of other languages. The absence of crossed Wernicke aphasia in our study participants may represent a left-hemispheric advantage for receptive language abilities in Bengali speakers. Further studies are required to clarify whether idiosyncrasies in the Bengali language may be responsible for the differential brain representation of language seen in our study participants.

Background: Crossed aphasia, a language disturbance in right-handed individuals secondary to a right hemisphere lesion, is rare, occurring in only l-2% of brain-lesioned patients. The precise neuro...

Background: Super-refractory status epilepticus (SRSE) is a critical neurological condition with a high mortality rate. There are only limited data to direct the treatment in SRSE, and surgery has been reported to successfully stop SRSE. We present a case of recurrent SRSE treated with urgent right temporal lobectomy in a right-handed woman which potentially saved her life but resulted in crossed sensory aphasia. Case Description: A 61-year-old woman with a recent episode of prolonged focal SRSE due to right frontotemporal meningioma and hyperkalemia was admitted for recurrence of seizures that evolved to SRSE despite aggressive treatment with multiple fosphenytoin antiepileptic drugs (AEDs) and anesthetics. The patient underwent a right temporal lobectomy to remove the encephalomalacic and gliotic tissue around the meningioma that had been resected during a previous admission. Postoperatively the patient had a protracted course with modest improvement after stepwise reduction in her AEDs; however, her recovery unveiled a severe crossed aphasia. Conclusion: Resective surgery is an effective treatment option in the treatment of SRSE, although the recovery period can be protracted. Crossed aphasia after right temporal lobectomy should be considered in patients where it is not possible to complete a presurgical evaluation of higher cortical functions.

Objectives: To characterize patterns of language lateralization in a right-handed woman with nonfluent/agrammatic primary progressive aphasia (nfvPPA) clinical picture despite showing a prevalent right-sided brain damage. Methods: We report a case of a 58-year-old woman with nfvPPA diagnosis (age at onset = 55) previously described as a crossed aphasia case with progranulin mutation. At 2years from the first visit, patient underwent 3DT1-weighted and a task-based functional MRI (fMRI). During the fMRI task, she was asked to perform a letter fluency test as the task of interest and to count forward as the control condition. Image processing and data analysis were performed using SPM12 and the effect of each task was tested at p < 0.05 FWE corrected. Results: The structural MRI confirmed a widespread right fronto-temporal atrophy mainly involving the right inferior frontal gyrus. During the letter fluency task, we observed an increased activation centered at the right inferior orbitofrontal gyrus and right middle frontal gyrus. By reducing the threshold, the pattern of functional activation was still dramatically prevalent at the right side. Conclusions: We provided evidence of the right language lateralization in a previously suspected crossed nfvPPA. Despite the long disease duration and the large amount of atrophy at the right side, there was no fMRI evidence of a left-hemisphere contribution to language function. We might speculate that compensatory effects do not appear when the premorbid language lateralization is purely right. The investigation of the underlying functional brain substrates in crossed nfvPPA cases may help understanding disease vulnerability in these neurodegenerative conditions.

Primary progressive aphasia is a clinical syndrome caused by a neurodegeneration of areas and neural networks involved in language, usually in the left hemisphere. The term "crossed aphasia" denotes an acquired language dysfunction caused by a lesion in the hemisphere ipsilateral to the dominant hand. A case is presented on a 75-year-old right-handed woman with a logopenic variant of primary progressive aphasia with word-finding difficulties of 2 years onset. The 18F-FDG PET/CT showed right temporoparietal hypometabolism. A functional MRI scan was performed during a verb naming task in order to characterise language lateralisation patterns. A similar activation pattern was observed in both hemispheres, with less activation than expected in bilateral inferior frontal gyrus. These findings support that logopenic variant of primary progressive aphasia should not be considered as a neurodegeneration starting in the left brain hemisphere, but as a syndrome characterised by asymmetric neurodegeneration of brain regions and neural networks involved in language.

Language and speech function is commonly accepted to be a heavily lateralized function. Greater than 95% of right-handed individuals have left hemispheric dominance for language, and reports in the literature of crossed aphasia (language deficits in a right-handed individual from right-sided pathology) are scant. We report the case of a 52-year-old woman presenting with crossed aphasia from a right temporal glioblastoma. We then expand on a discussion of crossed aphasia in the setting of brain tumors.

In the past few years, noninvasive cerebral stimulations have been used to modulate language task performance in healthy and aphasic patients. In this study, a dual transcranial direct current stimulation (tDCS) on anterior and posterior language areas was applied for 2 weeks to a patient with a possible crossed aphasia following a right hemisphere stroke. Inhibitory cathodal stimulation of the right Brodmann areas (BA) 44/45 and simultaneous anodal stimulation of the left BA 44/45 improved the patient’s performance in picture naming. Conversely, the same bilateral montage on BA 39/40 did not produce any significant improvement; finally, electrode polarity inversion over BA 39/40 yielded a further improvement compared with the first anterior stimulation. Our findings suggest that ipsilesional and contralesional areas could be useful in poststroke functional reorganization and provide new evidences for the therapeutic value of tDCS in aphasia.

Cognitive impairments associated with crossed aphasia were investigated in a single case study and a review of the literature. A review of literature identifies 4 main cognitive co-morbidities that are significantly associated with crossed aphasia. We present a case of confirmed crossed aphasia with dyslexia and dysgraphia, in which the latter two cannot be fully explained by the current lesion and are probable developmental disorders (dyslexia/dysgraphia). Extensive longitudinal cognitive investigations and a series of advanced imaging techniques (structural and functional) were used to investigate the cognitive and neuroanatomical basis of crossed aphasia and associated impairments in this patient. Using the results from the literature review and the single case study, we suggest that developmental disorders can be an underlying cause of partial right lateralisation shift of language processes, thereby supporting the theory that developmental disorders can be an underlying cause of crossed aphasia.

Background: Described over 100 years ago by Bramwell (1899) as an example of atypical cerebral dominance, crossed aphasia is a clinical condition where a lesion in the right hemisphere in a right-handed person leads to aphasia. Occurring worldwide only in a few cases, it is not known what initially leads to the ontogenetic lateralisation of language to the right brain. However, we know that certain kinds of pre-existing congenital lesions in the brain, in utero or post-partum, can usually impact the language lateralisation such that it develops in the opposite hemisphere. Aims: We present neurolinguistic data from a right-handed patient with crossed aphasia, who had an atypical subcortical crossed aphasia marked with a fractionated lateralisation of functions. Early in her life she had an unsuspected, pre-existing congenital (subcortical AVM) abnormality in the right hemisphere. Methods & Procedures: Clinical data in this single-participant study was obtained from a 20-year-old female who was seen for an ...

Anomalous lateralization of linguistic functions is observed in a small group of right-handed subjects with unilateral brain damage as either crossed aphasia (aphasia after right-hemisphere damage) or crossed nonaphasia (left hemisphere damage without aphasia but with symptoms of right hemisphere damage such as visuospatial deficits). The incidence of crossed nonaphasia is reportedly far less than that of crossed aphasia, where the latter, in turn, is comparatively rare (Alexander & Annett, 1996). In this report, we discuss a subject who presented with “crossed nonaphasia,” a clinical manifestation that often could go unnoticed. An attempt is made to explain the observed clinical manifestations from the perspectives of our current understanding of anomalous organization of cognitive functions in the brain as well as its implications on language representation in right-handed subjects.

The case of a female dextral patient (MN) is reported. MN sustained a partial frontotemporal infarction in the right hemisphere. Clinically, MN presented herself mainly with aphasic symptoms. The dextrality of the patient and the laterality of the lesion as well as the nature of language deficits would legitimate the diagnosis of a crossed aphasia, implying paradoxical lateralization of language in MN. However, comprehensive neuropsychological assessment revealed the presence of a global dysexecutive syndrome in MN, suggesting a general cognitive impairment, part of which must be the aphasic symptoms. General issues regarding the relationship between language and cognition and the lateralization of cognitive functions are discussed.

半側空間無視（USN）は右半球損傷患者に多くみられるが，右半球では空間性注意のネットワークを形成しているため，左半球損傷に比べてUSNの出現頻度が高いと言われている。治療については近年プリズム適応法（PA）が注目を浴びているが，空間表象を再構築することでUSNを改善するといわれている。今回我々はUSNに交叉性失語を合併する右半球損傷患者にPAを実施し，良好な成績が得られた。交叉性失語は生来右利きの人が右半球損傷により失語を生じるというもので，言語中枢が左半球に側性化されていないと考えられる。今回の結果は，空間表象機能は右半球優位のままで脳機能の冗長性が個体内でも生じることを示唆しており，治療法の選択に注意が必要であると思われた。

Introduction The purpose was to back up on all the arguments [1] , for to diagnose crossed aphasia (CA) our patient and improve rehabilitation. Subject A man of 45 years, right-handed, presented a dysarthria accompanied by a loss of verbal fluency, lack of word and paraphasias, after a parietal-temporal hematoma in right hemisphere. The interrogatory did not find a familial history on a left handedness. Brain imaging confirmed the integrity of the left hemisphere in the initial MRI and CT scan. The speech therapist assessment showed the oral picture naming test alack of the word (61/80, decreased lexical background, non-response, breaks) and semantic paraphasias. The questionnaire of the Boston Diagnostic Aphasia Examination of the repetition of sentences showed an effect of length and omissions of words. Reading words and sentences aloud contained substitutions, additions and paralexies. Listening was average (11/15: order execution, 6/12: understanding sentences and texts). Reading comprehension was average, 6/10. The writing contained many errors (perseveration, paragraphies literal and neologisms). The copy was altered. Automatic series were not preserved (Transcript of the alphabet). Brain lateralization test found an ocular dominance right and right lower limb (20/20). Neuropsychological assessment found disorders of attention (Stroop and Trail Making Test [TMT] with 4.12 standard deviation [sd] and the corrected T score 1.9 and 2.4 sd) and mental flexibility (TMT: 3.41 sd). An impaired working memory (WAIS: span = 7 and to place = 3) and logical reasoning (WAIS-III: 5). A deficit in verbal episodic memory (learning the verbal list of BEM 144: 1.31 sd) affect the encoding and retrieval processes. Discussion We have thus confirmed the diagnosis of crossed aphasia by eliminating a left handedness and a lesion in the left hemisphere. The speech therapist and neuropsychological allowed to assert the diagnosis of aphasia associated with cognitive disorders [2] . Therefore we associated the language rehabilitation in a targeted program on cognitive function and gained better results.

Crossed aphasia in dextrals (CAD) constitutes an interesting model for understanding the lateralisation and interaction of language with other cognitive functions in the brain. The authors present a study of a right-handed patient with Wernicke's aphasia following a right hemisphere cerebrovascular accident, who also had impairment in visuospatial skills. Although the patient presented a remarkable improvement in language symptoms on longitudinal follow-up, the combination of linguistic, visuospatial, and attentional impairments ultimately resulted in a persisting inability to perform complex tasks. The study of mild residual disturbances can improve our understanding of the interaction of language with other cognitive functions, going some way towards explaining the particular features found in CAD.

PubMedID: 16459730 Aphasia is a rare sign of multiple sclerosis (MS). Several different forms of aphasia have been reported in MS. We report, to our knowledge, the first case of a MS patient with crossed aphasia during an attack. © 2006 Edward Arnold (Publishers) Ltd.

The clinical study of crossed aphasia in dextrals (CAD) may shed light on the discreteness and modularity of several cognitive functions, such as language, gestures and visual spatial abilities, with respect to hemispheric lateralisation. Since 1975 over 180 cases have been described, employing, however, different criteria of assessment and classification. The purpose of this paper is to review them and to propose a set of diagnostic criteria that may be useful to single out a series of reliable CAD cases on which research can be safely carried out. A detailed analysis of such series is dealt with in terms of a number of characteristics concerning both the language disorder and the associated nonverbal cognitive impairments.

This study presents a thorough analysis of published crossed aphasia (CA) cases, including for the first time the cases published in Japanese. The frequency of specific symptoms was determined, and symptomatology differences based on gender, familial sinistrality, and CA subtype were investigated. Results suggested that the CA population is comparable to the left-hemisphere patient population. However, male were significantly more likely than female CA subjects to show a positive history of familial sinistrality. Typical right-hemisphere (i.e., nonlanguage-dominant) symptoms were frequent but rarely carefully reported or assessed. Results are compared with previous CA reviews and left-hemisphere aphasia. Suggestions for a more systematic assessment of the CA symptomatology are presented.

As an exception to so-called Broca's doctrine, assigning left-hemisphere dominance for language to dextrals and right-hemisphere dominance for language to sinistrals, Byrom Bramwell introduced, more than a century ago, the term crossed aphasia (CA) to denote the exceptional condition in which an aphasic syndrome results from a cerebral lesion ipsilateral to the dominant hand. Bramwell assumed that, in contrast to temporary manifestations, persistent CA is rare and essentially limited to the sinistral population. During the next decades, however, this view was challenged by several studies that reported persistent CA in dextrals (CAD). The initial concept of CA further eroded when studies on aphasia in sinistrals showed that CA is the rule and not the exception in this population. This paper reviews the early development and erosion of concepts in CA.

From the earliest descriptions onwards, the phenomenon of familial sinistrality (FS) has been strongly implicated in the concept of crossed aphasia in dextrals (CAD). In the early literature on CAD, a positive tract of FS (FS+) was generally regarded as the most important cause of anomalous language lateralisation in dextrals. Although in the more recent literature FS+ is generally regarded a strong exclusion criterion for CAD, in a corpus of 180 published CAD cases we encountered 26 patients with FS+ (14.4%). Critical analysis revealed that only a minority of these cases (5/26; 19%) sufficiently met the adopted criteria for an unambiguous diagnosis of vascular CAD (reliable CAD). One personal observation, reported in this paper, also fulfilled these criteria and is added to this group. To evaluate the presumed impact of FS+ on the anatomoclinical configurations of vascular CAD, all "reliable" CAD cases with FS+ were analysed in a three-epoch time-frame model for aphasia and matched for both aphasia type and lesion-aphasia profile with a representative group of vascular "reliable" CAD cases with negative FS (FS-). Close analysis of the aphasia characteristics revealed that the FS variable did not induce semiological differences between both FS groups. Although the limited study sample does not allow strong conclusions to be drawn, our findings seem to indicate that FS does not act as a strong determinant of lesion- behaviour relationships in CAD.

Crossed aphasia is caused by a right-hemisphere lesion in a right-handed person. Although this unusual language lateralisation pattern is a defining characteristic, there is disagreement among authors on additional diagnostic criteria. In addition, there is a significant amount of variability between patients as to the associated symptomatology, such as the presence of apraxic or visuospatial signs. Because of the rarity of crossed aphasia, the understanding of this clinical entity depends entirely on the analysis of published case studies. This paper presents two new cases of crossed aphasia, and discusses the major issues related to crossed aphasia diagnosis and symptomatology. Procedures for the assessment of crossed aphasia patients are also suggested.

われわれは，日本語と韓国語併用者の右利きの交叉性失語の１例を報告した。症例は75歳の男性で神経学的所見は，軽度の左不全片麻痺および全失語を認めていた。頭部MRI検査では，右中大脳動脈領域に広範な梗塞巣を認めた。言語所見は，自発話で「aigo : 」のみの残語を呈し全失語と診断された。本症例の言語習得タイプは等位型で，言語回復過程は，日本語の聴覚的理解のみが改善し，韓国語では改善がみられなかったことから，日本語の選択的回復形式と判断した。本症例の言語症状の改善の要因は， (1) 自然回復の可能性， (2) 日本語の習熟度が，韓国語の習熟度より高かった可能性， (3) 日本語のみの言語訓練を受けた影響の３つが考えられた。本症例は，日本語および韓国語で右利き交叉性失語を呈しており，両国語の言語機能は，右半球に側性化していたと考えられた。

右中心前・後回を中心とした梗塞病変により，交叉性失語を呈した症例の発症初期より約２年間の経過を報告した。症例は62歳の右利き男性で，軽度の左片麻痺とmutismで発症した。発症数日で麻痺は回復したが発語は不可能であった。理解は良好であり，仮名の錯書を示した。全般的な言語能力が回復した後にも構音の障害が残存し，定型的なBroca失語の病像を呈した。 近年，持続する構音の障害を伴うBroca失語の責任病巣として, Broca領域よりもむしろ左中心前・後回の病巣が注目されている。交叉性失語には，病巣部位と言語症状の対応が左半球病変による失語症と鏡像をなすタイプと非定型的なタイプがあることが知られているが，本例は鏡像的なタイプであると考えられる。また，本例は発話不可能な時期に歌唱が可能であったことより，歌唱のメカニズムと半球優位性についても検討を加えた。

Journal Article; Knowledge on the patterns of repetition amongst individuals who develop language deficits in association with right hemisphere lesions (crossed aphasia) is very limited. Available data indicate that repetition in some crossed aphasics experiencing phonological processing deficits is not heavily influenced by lexical-semantic variables (lexicality, imageability, and frequency) as is regularly reported in phonologically-impaired cases with left hemisphere damage. Moreover, in view of the fact that crossed aphasia is rare, information on the role of right cortical areas and white matter tracts underpinning language repetition deficits is scarce. In this study, repetition performance was assessed in two patients with crossed conduction aphasia and striatal/capsular vascular lesions encompassing the right arcuate fasciculus (AF) and inferior frontal-occipital fasciculus (IFOF), the temporal stem and the white matter underneath the supramarginal gyrus. Both patients showed lexicality effects repeating better words than non-words, but manipulation of other lexical-semantic variables exerted less influence on repetition performance. Imageability and frequency effects, production of meaning-based paraphrases during sentence repetition, or better performance on repeating novel sentences than overlearned clichés were hardly ever observed in these two patients. In one patient, diffusion tensor imaging disclosed damage to the right long direct segment of the AF and IFOF with relative sparing of the anterior indirect and posterior segments of the AF, together with fully developed left perisylvian white matter pathways. These findings suggest that striatal/capsular lesions extending into the right AF and IFOF in some individuals with right hemisphere language dominance are associated with atypical repetition patterns which might reflect reduced interactions between phonological and lexical-semantic processes. Yes

交叉性失語には, 右半球内の言語表象の組織化が広範で異常なもの (異常交叉性失語) と, 通常の非交叉性失語の際の左半球内の組織化の鏡像を呈するもの (鏡像交叉性失語) とがある.前者は早期発達段階における左半球機能の故障によるものであり, 右半球内の損傷部位と関係なく, 非流暢性発話, 失文法など一定の症状を呈しやすいとされている.後者は遺伝を含む生物学的素因によるものであり, 症状と病巣部位との関係は左半球損傷による非交叉性失語とよく対応する.一方, 交叉性失語の合併症状の研究から, 種々の高次大脳機能の交叉の起こりやすさが問題にされ, 言語機能の方が視空間機能よりも交叉しやすいことが分かった.近年は, 交叉性「右半球症候群」ないし機能側在性の逆転 (reversed laterality) なる名称のもとに, 稀有な症例が報告されているが, これらの側在性の逆転の原因としては生物学的素因の関与が想定されることが多い.

Purpose The lateralization of cognitive functions in crossed aphasia in dextrals (CAD) has been explored and compared mainly with cases of aphasia with left hemisphere damage. However, comparing the neuropsychological aspects of CAD and aphasia after right brain damage in left-handers (ARL) could potentially provide more insights into the effect of a shift in the laterality of handedness or language on other cognitive organization. Thus, this case study compared two cases of CAD and one case of ARL. Materials and methods The following neuropsychological measures were obtained from three aphasic patients with right brain damage (two cases of CAD and one case of ARL); language, oral and limb praxis, and nonverbal cognitive functions (visuospatial neglect and visuospatial construction). Results All three patients showed impaired visuoconstructional abilities, whereas each patient showed a different level of performances for oral and limb praxis, and visuospatial neglect. Conclusion Based on the analysis of these three aphasic patients' performances, we highlighted the lateralization of language, handedness, oral and limb praxis, visuospatial neglect and visuospatial constructive ability in aphasic patients with right brain damage.

The occurrence of crossed aphasia as a complication after temporal lobe epilepsy surgery is extremely rare. We report the case of a 47-year-old right-handed patient with drug-resistant mesial temporal lobe epilepsy (MTLE) who developed a transitory aphasic syndrome after a right temporal anterior lobectomy. This syndrome was characterized by anomia, poor verbal fluency, verbal perseveration, and verbal comprehension difficulties. He also showed writing difficulties, reading substitutions, and calculation task errors. The patient was regularly assessed with language tasks, and showed a spontaneous and progressive recovery of his symptoms, with remaining naming difficulties. We discuss the role that epileptogenic zone could play in cortical reorganization of the language systems.

We report the case of a right-handed patient who developed a global aphasia after a right hemisphere cerebrovascular lesion. Despite having extensive damage to the right hemisphere this patient did not show the expected emotional features that usually follow right hemisphere lesions such as anosognosia, indifference reaction or undue cheerfulness, but displayed anxiety, frustration, outbursts of crying, and withdrawal characteristic of the catastrophic reaction that usually follows left hemisphere lesions. This case demonstrates that ‘crossed’ aphasics may not only have a reversed lateralization of language and related cognitive abilities, but a reversed affective lateralization as well.

Simon M McCreaDepartments of Neurology and Neuroophthalmology, University of British Columbia, Vancouver, British Columbia, CanadaAbstract: Intuition is the ability to understand immediately without conscious reasoning and is sometimes explained as a ‘gut feeling’ about the rightness or wrongness of a person, place, situation, temporal episode or object. In contrast, insight is the capacity to gain accurate and a deep understanding of a problem and it is often associated with movement beyond existing paradigms. Examples include Darwin, Einstein and Freud’s theories of natural selection, relativity, or the unconscious; respectively. Many cultures name these concepts and acknowledge their value, and insight is recognized as particularly characteristic of eminent achievements in the arts, sciences and politics. Considerable data suggests that these two concepts are more related than distinct, and that a more distributed intuitive network may feed into a predominately right hemispheric insight-based functional neuronal architecture. The preparation and incubation stages of insight may rely on the incorporation of domain-specific automatized expertise schema associated with intuition. In this manuscript the neural networks associated with intuition and insight are reviewed. Case studies of anomalous subjects with ability–achievement discrepancies are summarized. This theoretical review proposes the prospect that atypical localization of cognitive modules may enhance intuitive and insightful functions and thereby explain individual achievement beyond that expected by conventionally measured intelligence tests. A model and theory of intuition and insight’s neuroanatomical basis is proposed which could be used as a starting point for future research and better understanding of the nature of these two distinctly human and highly complex poorly understood abilities.Keywords: intuition, insight, nonverbal decoding, nonverbal sequencing, unconscious and conscious processes, right hemisphere dominance, atypical localization of cognitive functions, crossed aphasia, inverse cognitive modeling, emergent properties, anomalous functions, specialization, visual gesture lexicon, crosslinguistic fluency, achievement–ability discrepancy, IQ threshold theory, functional capacity, House–Tree–Person, drawings, clinical intuition, clinical psychology

A patient presenting the association of anomalous cerebral dominance for language, as revealed by crossed aphasia, and partial visceral situs inversus is described. Although it cannot be excluded that the two abnormalities coincided by chance, it is suggested that they both resulted from a single aberration of development.

We report a case of crossed aphasia in a strongly right-handed woman due to a parieto-occipital tumor in the right hemisphere, documented by CT and MR images. Neuropsychological assessment was conducted on four different occasions: results revealed an uncommon feature in our case, because of the nature of the lesion and the evolution of the clinical picture. These findings are discussed in relation to the literature.

Crossed aphasia reflects an unusual latcralization pattern characterized by a dissociation between manual and language hemispheric dominance in a right-handed individual. In order to circumscribe the syndrome of crossed aphasia, authors have developed stringent exclusion criteria to define that syndrome. We believe that such an approach artificially created a homogeneous syndrome. As an alternative to the rigorous exclusion criteria approach, we propose to broaden the definition of crossed aphasia to accommodate the various demonstrated aphasic symptoms. The interest in crossed aphasia can then shift from the search for a universal symptom complex to different subgroups of patients. Indeed, there now appears to be overwhelming evidence (including Wada experiments) to indicate that crossed aphasia can cither be the mirror image of uncrossed aphasia or indicate a bilateral language representation pattern. Two patients are presented and their symptoms are discussed in the light of the literature. On...

交叉性失語によって失文法を呈した2症例に対して, 自発話の特徴, 助詞や動詞の課題成績, 統語理解力の点から, 2例の文法障害の特徴を比較検討したところ, 次のような知見を得た.症例1は, 自発話において動詞の語彙の省略や助詞の省略, および動詞の活用語尾や助動詞の省略といった述部の不完全さが認められたが, 語順の混乱や助詞の誤用はみられなかった.また助詞や動詞の活用, 動詞の喚語に関する課題の成績は良好で, 統語理解力の低下もなかった.症例2は, 自発話において動詞の語彙の省略や錯語, 助詞の誤用があり, 語順の混乱もみられたが, 助動詞を使用し, まれに長い連鎖の述部の表出がみられた.また助詞や動詞の活用に関する課題の成績は不良で, 動詞の喚語困難がみられ, 統語理解力の低下も認められた.以上の結果より, 2例の文法障害の発現機序について考察を加える.

右頭頂部の脳出血が責任病変と考えられた右利き交叉性失語の1例に対し, positron emission tomography (PET) を含む放射線学的検査を施行した.症例は46歳, 男性.1989年5月29日朝, 突然数字と平仮名が読めなくなった.片仮名と漢字はとくに不自由を感じなかったが, 復唱, 数字の順唱, 逆唱は著明に障害されていた.頭部CTでは右頭頂葉に血腫を認めた.8月16日精査のため当科入院.MRIでは右頭頂葉の血腫のほか, 両側白質に陳旧性の小梗塞巣が散在していた.PETでは血腫を含んだ部位に脳血流, 脳酸素消費量の明らかな左右差を認め, 失語発症の責任病巣は血腫の部位と考えられた.その他の部位に明らかな左右差はみられなかった.交叉性失語の機序を解明する上で, 従来の器質的変化の検索に加え, 機能的変化を検出しうるPETを用いた脳循環代謝の検討が有用であると考えられた.

Atypical patterns of language activation in functional MRI (fMRI) are not unusual, particularly in patients with severe epilepsy. Still, the functional significance of these activations is under debate. We describe a case of a right-handed patient affected by drug-refractory right temporal lobe epilepsy in whom pre-surgical fMRI showed bilateral language activations, greater in the right hemisphere (RH). After surgery, a right subdural hematoma caused epileptic status and severe aphasia. This post-surgical complication of a crossed aphasia confirmed the prior fMRI findings of RH language thus stressing the value of pre-surgical fMRI evaluations, even when surgery is planned in the RH of a right-handed patient.

左半側空間失認をともなった交叉性失語４例を報告し，若干の考察を試みた。症例Ａ (女，45歳) は右前頭葉損傷 (神経膠腫の手術例) で構音失行それに錯書が特徴的で，病巣は右側脳室前角周辺を含んで，前頭葉から側頭葉の一部に及んでいた。症例Ｂ (女，60歳) は右側頭葉から後頭葉の広範な損傷であるが，聴覚理解は当初から正常で，喚語困難と錯書 (ジャルゴン失書) が顕著であった。症例Ｃ (女，59歳) は右側頭葉から頭頂葉の損傷 (血腫除去手術例) で重度の全失語となり，発声はできても発語はほとんど不可能であり，書字も全くできなかった。症例Ｄ (男，71歳) は右側脳室前角周辺の限局した損傷であるが，失文法と失書が主症状で，聴覚理解と文字理解は良好であった。そしてすべての症例に左半側空間失認がみられた。

Crossed aphasia in dextrals (CAD) following pure subcortical lesions is rare. This study describes a right-handed patient with an ischemic lesion in the right thalamus. In the post-acute phase of the stroke, a unique combination of ‘crossed thalamic aphasia’ was found with left visuo-spatial neglect and constructional apraxia. On the basis of the criteria used in Mariën et al. [67], this case-report is the first reliable representative of vascular CAD following an isolated lesion in the right thalamus. Furthermore, this paper presents a detailed analysis of linguistic and cognitive impairments of ‘possible’ and 'reliable' subcortical CAD-cases published since 1975. Out of 25 patients with a pure subcortical lesion, nine cases were considered as ‘possibly reliable or reliable’. A review of these cases reveals that: (1) demographic data are consistent with the general findings for the entire group of vascular CAD, (2) the neurolinguistic findings do not support the data in the general CAD-population with regard to (a) the high prevalence of transcortical aphasia and (b) the tendency towards a copresence of an oral versus written language dissociation and a ‘mirror-image’ lesion-aphasia profile, (3) subcortical CAD is not a transient phenomenon, (4) the lesion-aphasia correlations are not congruent with the high incidence of anomalous cases in the general CAD-population, (5) neuropsychological impairments may accompany subcortical CAD.

The famous Swiss writer Charles-Ferdinand Ramuz suffered a stroke at 65 years, which he called ‘the adventure’ or ‘the accident’. He developed language disturbances suggesting crossed aphasia in a right hander with left hemiparesis. This uncommon pattern allowed him to continue to write his diary and to report his disturbances, with a unique depth and precision, especially for cognitive-emotional changes. Language and motor dysfunction recovered within a few weeks, but Ramuz complained of persisting emotional flattening alternating with irritability, fatigue, depression, anxiety, and concentration difficulty, which gave him the feeling to have become another person and to be inhabited by a stranger, whom he compared with devils. Ramuz fought several months to resume his literary activity, having the impression to have lost inspiration and creativity. However, the novels he wrote less than 6 months after stroke show no stylistic changes and have been found to be of the same quality as his previous production. Ramuz even ‘used’ his stroke experience in his work, in particular in a novel depicting an old man who has a stroke and dies of it. Ramuz’s diary, with his own daily description of stroke features and consequences during acute and recovery phases, is a unique document in a writer of his importance, and provides invaluable information on subjective emotional and cognitive experience of stroke.

Apraxia is a disorder that is characterized by an impairment in the ability to perform new or previously learned movements that cannot be explained by sensory or motor abnormalities. It is often not recognized by the patient and family members, and the prevalence of apraxia may therefore be somewhat underestimated. The prognosis for recovery is very good, and the presence of apraxia during the acute period after a stroke is not associated with an overall worse prognosis for recovery. Although apraxia most often coexists with aphasia, the two phenomena can also be dissociated. Studies of right- and left-handed patients with apraxia have revealed that apraxia always results from a lesion of the hemisphere contralateral to the dominant hand. The theoretical importance of apraxia, therefore, is that it demonstrates a very close relationship between hemispheric dominance for programming of motor acts and handedness. Whereas the relationship between cerebral language dominance for language and handedness is highly variable, particularly in left-handers, the relationship between cerebral dominance for motor programming and handedness appears to be much more robust.

To the Editor: I read with interest the article by Hund-Georgiadis et al1 on crossed nonaphasia in a dextral with left hemispheric lesions published in the November 2001 issue of Stroke . They concluded from their data that different modalities such as language perception and production, attention, and motor performance are processed exclusively by one hemisphere when atypical cerebral dominance is present. They also suggested that the underlying functional organization of language remains rare and unclear in these cases. Our studies in normal subjects using functional transcranial Doppler (fTCD) suggest that this may not be rare after all. Left hemispheric lateralization for language was found in 61.5% of neurologically intact dextrals.2 Human pathology data obtained by Geschwind and Levitsky3 found that the planum temporale of the temporoparietal junction is larger in the left hemisphere in ≈60% of the population.3 Furthermore, there was a high incidence of right-hemisphere lateralization for language in as much as 38.5% of neurologically intact dextrals.2 Dyslexics had a pattern that was opposite the normal pattern.2 Recently, the use of functional MRI and fTCD offers new approaches with more precise determinations of cerebral lateralization for language. To support the …

PubMedID: 9686282 A 55 year-old, right-handed, hypertensive woman with global aphasia, due to a spontaneous hemorrhage in the right putamen extending to the periventricular white matter was examined thirteen days after the acute onset of stroke. She had left hemiplegia and inability to speak. She displayed no spontaneous speech output and was capable only of occasional undifferentiated grunts in conversation. Other language modalities such as auditory and reading comprehension, naming, repetition and writing were severely impaired. Her aphasia was classified as global aphasia. Forty-five days after the onset of stroke, rapid recovery from the aphasia with mild deficits in speaking, naming, and repetition was detected. This case is a good example of crossed aphasia, favouring the importance of deep structures of the right hemisphere in this type of aphasia. Rapid recovery is an important feature.