Global aphasia without hemiparesis: language profiles and lesion distribution

OBJECTIVES: Global aphasia without hemiparesis (GAWH) is an uncommon stroke syndrome involving receptive and expressive language impairment, without the hemiparesis typically manifested by patients with global aphasia after large left perisylvian lesions. A few cases of GAWH have been reported with conflicting conclusions regarding pathogenesis, lesion localisation, and recovery. The current study was conducted to attempt to clarify these issues. METHODS: Ten cases of GAWH were prospectively studied with language profiles and lesion analysis; five patients had multiple lesions, four patients had a single lesion, and one had a subarachnoid haemorrhage. Eight patients met criteria for cardioembolic ischaemic stroke. RESULTS: Cluster analysis based on acute language profiles disclosed three subtypes of patients with GAWH; these clusters persisted on follow up language assessment. Each cluster evolved into a different aphasia subtype: persistent GAWH, Wernicke's aphasia, or transcortical motor aphasia (TCM). Composite lesion analysis showed that persistent GAWH was related to lesioning of the left superior temporal gyrus. Patients with acute GAWH who evolved into TCM type aphasia had common lesioning of the left inferior frontal gyrus and adjacent subcortical white matter. Patients with acute GAWH who evolved into Wernicke's type aphasia were characterised by lesioning of the left precentral and postcentral gyri. Recovery of language was poor in all but one patient. CONCLUSIONS: Although patients with acute GAWH are similar on neurological examination, they are heterogeneous with respect to early aphasia profile, language recovery, and lesion profile.     

A case of acquired childhood aphasia with evolution of global aphasia into transcortical sensory aphasia

Abstract

A 11–year-old right-handed boy showed global aphasia after an infarct in the distribution of the left middle cerebral artery involving the whole language area, following an operation for ‘moya-moya disease’. Thus, anatomoclinical correlation between the CT lesion site and the resulting aphasic syndrome in this case was similar to that described in adults. However, he demonstrated rapid recovery of language fluency with poor recovery of language comprehension, in contrast to comparable adult cases. Consequently, his global aphasia resolved into transcortical sensory aphasia. This case seems to support the current view that recovery of fluency in childhood aphasia is quicker and more extensive than in adults.     

Slowly progressive aphasia without generalized dementia: studies with positron emission tomography

Slowly progressive aphasia without generalized dementia is a degenerative syndrome selectively affecting dominant hemisphere language areas. We report changes in regional glucose metabolism measured by positron emission tomography in two patients with this condition. Striking abnormalities of glucose utilization in the left cerebral cortex were demonstrated in both patients. The findings of other neurodiagnostic studies were relatively unremarkable. The first patient had a 3-year history of progressive anomia and impaired auditory verbal recall. An electroencephalogram was normal, and computed tomography showed mild left perisylvian atrophy. Positron emission tomography revealed profound hypometabolism in the left temporal regions. The second patient also had a 3-year history of progressive anomia. Electroencephalography, computed tomography, and magnetic resonance imaging scans were normal. Positron emission tomography showed a major reduction in left parietal glucose utilization, with a lesser decrement in left temporal metabolism. Neither patient demonstrated significant contralateral or global abnormalities such as those reported in positron emission tomographic studies of Alzheimer's disease with or without focal clinical features. These observations support the concept of adult-onset progressive aphasia without dementia as a clinical syndrome distinct from Alzheimer's disease.     

Foreign accent syndrome as the initial sign of primary progressive aphasia

Foreign accent syndrome (FAS) is a rare speech disorder characterised by the emergence of a new accent, perceived by listeners as foreign. FAS has usually been described following focal brain insults, such as stroke. We describe the unusual case of a woman presenting with FAS as the earliest symptom of progressive degenerative brain disease. At presentation, she showed no language or other cognitive impairment, and functional and structural brain imaging were normal. Follow-up 1 year later revealed the emergence of mild expressive language problems. Repeat functional neuroimaging showed mild hypoperfusion of the perisylvian speech area of the left hemisphere, and structural imaging showed mild left perisylvian atrophy. We interpret the case as an unusual presentation of primary progressive non-fluent aphasia. The case provides further evidence of the variable and circumscribed nature of the clinical presentation of focal cerebral degeneration.     

Neuroanatomic correlation of the post-stroke aphasias studied with imaging

BACKGROUND AND PURPOSE: Stroke is the leading cause of disability in many countries. Aphasia is a common sign of stroke that is observed in about one-third of stroke patients and contributes to disease morbidity. However, the relationship between anatomy and different forms of aphasia remains poorly understood. We intend to study the characteristics of aphasia in the acute stage of stroke and to identify neuroanatomical correlates using MRI. METHODS: Lesion sites were selected from 1198 patients with cerebral infarction, who were hospitalized in the stroke unit of our hospital between March 2002 and March 2006. We enrolled 325 patients who fulfilled our criteria. All patients received an MRI examination within 1 week after admission and were evaluated with the Western battery aphasia (WAB) test, in order to determine what type of aphasia they had. The severity of their language deficit was further classified using the Boston diagnostic aphasia examination (BDAE) severity grading standard. RESULTS: Among 1198 cases, five cases with Broca's areas and four cases with Wernicke's areas lesions on MRI works were free of language deficits. Within the 325 patients who demonstrated clinical signs of aphasia, the results of WAB showed that there were 83 Broca' aphasia cases, 48 Wernicke's aphasia cases, 12 conduction aphasia cases, 36 transcortical motor aphasia cases, 17 transcortical sensory aphasia cases, 19 transcortical mixed aphasia cases, 58 global aphasia cases and 52 anomic aphasia cases. Two hundred and eighty-eight cases were located within classical language centers while 37 cases were located at other sites. In 325 aphasia patients with grade criteria of BDAE of grades 0, 1, 2, 3 or 4, there were 84, 79, 77, 63 and 22 cases respectively. Many of cases with grades 0 and 1 were distributed within classical language centers. CONCLUSION: This study showed that it is possible to draw a neuroanatomical map of aphasia that encompasses the 95% of aphasia cases. It also demonstrates that the main determinant of aphasic disorders is the neuroanatomical location of the lesion. Furthermore, this study shows that most lesion locations associated with specific aphasic disorders fit classical data associated with previous aphasia research. More importantly, the language disorders of patients whose lesions were located at classical language centers were more serious. Consequently, this paper demonstrates the power of MRI in prognosticating the potential for a patient to recover from aphasia due to stroke.     

Impairment of language is related to left parieto-temporal glucose metabolism in aphasic stroke patients

Summary Twenty-six aphasic patients who had an ischaemic infarct in the territory of the left middle cerebral artery (MCA) were investigated. Cranial computed tomography (CT) showed various lesion sites: infarcts restricted to cortical structures in 12 patients, combined cortical and subcortical infarcts in 7 and isolated subcortical infarcts sparing the left cortex in another 7 cases. ¹⁸F-2-fluoro-2-deoxyglucose positron emission tomography revealed remote hypometabolism of the left convexity cortex and of the left basal ganglia, which was extended further than the morphological infarct zone in all cases. Types and degrees of aphasia were classified using the Aachener Aphasie Test (AAT): 10 patients had global aphasia, 2 Broca's, 5 Wernicke's, and 5 amnesic aphasia. Four patients suffered from minimal or residual aphasic symptoms. The AAT results were compared with the regional cerebral metabolic rates of glucose of the left hemisphere. Irrespective of the infarct location all five AAT subtests (Token test, repetition, written language, confrontation naming, auditory and reading comprehension) were closely correlated among each other and with left parieto-temporal metabolic rates, whereas left frontal and left basal ganglia metabolism showed no significant correlation. The close relation between left temporo-parietal functional activity and all five AAT subtests suggests that the different aspects of aphasia tested by AAT can be related to a common disorder of language processing in those areas.     

Progressive aphasia without dementia: two cases with focal spongiform degeneration

Two patients with the syndrome of progressive aphasia without evidence of generalized dementia underwent postmortem neuropathological examinations. In both patients, characteristic changes of Alzheimer's disease, Pick's disease, or Creutzfeldt-Jakob disease were absent. Both patients showed a focal spongiform change involving primarily layer 2 of the left inferior frontal gyrus (and temporal cortex in Patient 1) and a mild astrocytosis in layer 2 and deeper cortical layers. This focal, spongiform cortical degeneration in patients with progressive aphasia does not appear to duplicate any known central nervous system degenerative disease.     

Excellent recovery of aphasia in a patient with complete injury of the arcuate fasciculus in the dominant hemisphere

The arcuate fasciculus (AF) is the neural tract that connects Wernicke's area and Broca's area. The main role of the AF is speech repetition; therefore, injury to the AF typically causes conduction aphasia. We report on a patient who showed excellent recovery of aphasia despite complete injury of the AF due to a cerebral infarct. A 54-year-old, right-handed male presented with aphasia and right hemiparesis. Brain MRI showed an infarct in the left centrum semiovale and corona radiata. Diffusion tensor tractography for the AF was reconstructed using DTI-studio software. The Korean-Western Aphasia Battery (K-WAB) was used for measurement of language function. On K-WAB at 1 week after onset, his aphasia type was compatible with global aphasia (aphasia quotient: 12‰, fluency: 5‰, comprehension: 24‰, repetition: 15‰, and naming: 31‰). The patient underwent rehabilitative therapy, including language therapy and medication, which is known to facilitate recovery from aphasia, for a period of 24 months. His aphasia had improved to a nearly normal state at 30 months after onset; aphasia quotient: 93‰ (fluency: 91‰, comprehension: 92‰, repetition: 85‰, and naming: 96‰). The left AF showed a complete disruption on 27-month diffusion tensor tractography. Findings from this study suggest the possibility that aphasia might show good recovery, even in cases of severe injury of the AF.     

Present day concepts of the cerebral organization of language based on findings in bilingual Oriental patients with crossed aphasia (author's transl)

Two right-handed bilingual (English and Cantonese) Chinese patients were observed to have crossed aphasia. A preliminary study of a multiracial population with left hemiplegia did not show a higher incidence of aphasia in Chinese subjects. These two extremely rare cases are interesting examples of a particular type of cerebral organization of language.     

Crossed aphasia: a PET follow up study of two cases.

Two cases of aphasia after right hemispheric stroke in right handed patients are described. The first patient had a severe mixed transcortical aphasia, apraxia and neglect after a lesion involving the right lenticular nucleus and periventricular white matter; aphasia was still present after three months. The second patient had a mild, transient fluent aphasia after a small right hemispheric periventricular lesion. Studies with [18F]FDG and positron emission tomography (PET) showed functional depression extending to the structurally unaffected left hemisphere in both patients in the acute stage. After three months, in the patient with persistent aphasia, metabolism was still reduced in the right hemisphere, with some recovery of hypometabolism on the left, while metabolic values had returned to normal in the patient with full language recovery. A close parallelism between glucose metabolism and clinical course in crossed aphasia is shown, as well as the presence of a functional involvement of the structurally unaffected left hemisphere in the acute stage.     

Transcortical sensory aphasia due to extensive infarction of left cerebral hemisphere]

We report a case of transcortical sensory aphasia occurred after extensive infarction of left cerebral hemisphere. A 68-year-old, right-handed man with atrial fibrillation suddenly developed cerebral embolism of left middle cerebral artery. He was treated conservatively, and the right hemiplegia, aphasia, apraxia in a slight degree and right hemispatial neglect in a slight degree consequently existed. MRI showed a large cortical and subcortical infarct lesion including the left Broca's area, central region, perisylvian area with Wernicke's area and temporal lobe. In contrast, neuropsychological evaluation using the Western Aphasia Battery (WAB) demonstrated transcortical sensory aphasia, e.g., fluency 8, auditory comprehension 1. repetition 10 and object naming 2.4. In addition to preserved repetition, both linguistic prosody and affective prosody were well preserved. Most cases with transcortical sensory aphasia are known to occur with the lesion including temporo-parieto-occipital junction of dominant hemisphere. Our patient and a few other reported cases of transcortical sensory aphasia had a lesion in perisylvian area including Wernicke's area. Therefore, it is possible that their minor hemisphere worked selectively for repetition. Furthermore, we suggest that this patient presented dissociative aphasia that all the process of repetition and the function of linguistic and emotional prosody were represented in the right hemisphere and the other functions including comprehension of word meanings were existed in the left hemisphere. We believe that our case of transcortical sensory aphasia with dissociative aphasia gives a suggestion about the mechanism and localization of repetition and prosody in the whole system of language.     

Broca's area aphasias: aphasia after lesions including the frontal operculum

We report 9 cases of aphasia following lesions in the region of the left frontal operculum. It is not possible to capture their variety of clinical manifestations with the simple labels of "Broca's area aphasia." or "Broca's area aphasia." Analysis of the breakdown of various components of speech and language in these cases suggests that the operculum, lower motor cortex, and subjacent subcortical and periventricular white matter contain critical parts of different language systems. These systems can be independently impaired. There are several common language syndromes that follow damage that includes the left frontal operculum. These syndromes reflect the effects of the direction and extent of the lesion in the various language systems.     

Global aphasia without hemiparesis

Three patients acutely developed global aphasia, but did not manifest the typical accompanying right hemiparesis. Computed tomography and magnetic resonance imaging studies demonstrated that the patients had two discrete left hemisphere lesions, one in the anterior language cortices or language-related subcortical areas, and one in the posterior language cortices. Cerebral angiography showed that two patients had complete occlusion of the left internal carotid artery, and the third had an intraluminal "clot" in the supraclinoid portion of the left internal carotid, findings suggestive of an embolic etiology. Our cases indicate that global aphasia without hemiparesis predicts two discrete lesions and a particularly good recovery of speech and language.     

Evidence of cortical reorganization of language networks after stroke with subacute Broca's aphasia: a blood oxygenation level dependent-functional magnetic resonance imaging study

Aphasia is an acquired language disorder that is a common consequence of stroke.The pathogenesis of the disease is not fully understood,and as a result,current treatment options are not satisfactory.Here,we used blood oxygenation level-dependent functional magnetic resonance imaging to evaluate the activation of bilateral cortices in patients with Broca's aphasia 1 to 3 months after stroke.Our results showed that language expression was associated with multiple brain regions in which the right hemisphere participated in the generation of language.The activation areas in the left hemisphere of aphasia patients were significantly smaller compared with those in healthy adults.The activation frequency,volumes,and intensity in the regions related to language,such as the left inferior frontal gyrus(Broca's area),the left superior temporal gyrus,and the right inferior frontal gyrus(the mirror region of Broca's area),were lower in patients compared with healthy adults.In contrast,activation in the right superior temporal gyrus,the bilateral superior parietal lobule,and the left inferior temporal gyrus was stronger in patients compared with healthy controls.These results suggest that the right inferior frontal gyrus plays a role in the recovery of language function in the subacute stage of stroke-related aphasia by increasing the engagement of related brain areas.     

Global Aphasia with Seizure Onset in the Dominant Basal Temporal Region

Summary: A 33-year-old right-handed woman had intractable simple and complex partial seizures (SPS, CPS) that began with global aphasia. EEG closed-circuit TV (EEG-CCTV) monitoring with sphenoidal electrodes showed left inferomesial temporal ictal onset of CPS. Subdural electrodes were implanted over the left frontotemporal convexity, sub temporally and subfrontally. Stimulation of the basotemporal cortex produced global aphasia. A posterolaterotemporal language area was also identified. Spontaneous SPS had focal onset in the basal temporal language area (BTLA). Ictal discharges did not involve the posterotemporal region. This case shows that aphasic speech arrest at seizure onset may be due to seizure discharge in the basotemporal region and that the BTLA is clinically relevant in seizure semiology.     

Recovery of language function in Korean-Japanese crossed bilingual aphasia following right basal ganglia hemorrhage

ABSTRACT

Few studies have investigated language recovery patterns and the mechanisms of crossed bilingual aphasia following a subcortical stroke. In particular, Korean-Japanese crossed bilingual aphasia has not been reported. A 47-year-old, right-handed man was diagnosed with an extensive right basal ganglia hemorrhage. He was bilingual, fluent in both Korean and Japanese. After his stroke, the patient presented with crossed aphasia. We investigated changes in the Korean (L1) and Japanese (L2) language recovery patterns. Both Korean and Japanese versions of the Western Aphasia Battery (WAB) were completed one month after the stroke, and functional magnetic resonance imaging (fMRI) was performed using picture-naming tasks. The WAB showed a paradoxical pattern of bilingual aphasia, with an aphasia quotient (AQ) of 32 for Korean and 50.6 for Japanese, with Broca’s aphasia. The patient scored better in the Japanese version of all domains of the tests. The fMRI study showed left lateralized activation in both language tasks, especially in the inferior frontal gyrus. After six months of language therapy targeting L1, the Korean-WAB score improved significantly, while the Japanese-WAB score showed slight improvement. In this case, the subcortical lesion contributed to crossed bilingual aphasia more highly affecting L1 due to loss of the cortico-subcortical control mechanism in the dominant hemisphere. The paradoxical pattern of bilingual aphasia disappeared after lengthy language therapy targeting L1, and the therapy effect did not transfer to L2. Language recovery in L1 might have been accomplished by reintegrating language networks, including the contralesional language homologue area in the left hemisphere.     

Aphasia with left occipitotemporal hypometabolism: A novel presentation of posterior cortical atrophy?

Alzheimer’s disease is a common neurodegenerative disease often characterized by initial episodic memory loss. Atypical focal cortical presentations have been described, including the logopenic variant of primary progressive aphasia (lvPPA) which presents with language impairment, and posterior cortical atrophy (PCA) which presents with prominent visuospatial deficits. Both lvPPA and PCA are characterized by specific patterns of hypometabolism: left temporoparietal in lvPPA and bilateral parietoccipital in PCA. However, not every patient fits neatly into these categories. We retrospectively identified two patients with progressive aphasia and visuospatial deficits from a speech and language based disorders study. The patients were further characterized by MRI, fluorodeoxyglucose F18 and Pittsburgh Compound B (PiB) positron emission tomography. Two women, aged 62 and 69, presented with a history of a few years of progressive aphasia characterized by fluent output with normal grammar and syntax, anomia without loss of word meaning, and relatively spared repetition. They demonstrated striking deficits in visuospatial function for which they were lacking insight. Prominent hypometabolism was noted in the left occipitotemporal region and diffuse retention of PiB was noted. Posterior cortical atrophy may present focally with left occipitotemporal metabolism characterized clinically with a progressive fluent aphasia and prominent ventral visuospatial deficits with loss of insight.     

低频重复经颅磁刺激对脑梗死失语的治疗作用及其对脑电活动的影响

目的 观察低频重复经颅磁刺激（low-rTMS）对脑梗死失语的治疗作用和其对脑电活动的影响.方法 选取左半球脑梗死后运动性失语右利手的患者15例,经ABC失语检查表评定后随机分为对照组7例和治疗组8例.对照组予常规药物和语言康复治疗;治疗组在对照组治疗基础上予low-rTMS治疗.rTMS治疗方法：频率1 Hz、强度为运动阈值80%、部位为右侧大脑半球Broca区、每序列50次脉冲、每天10个序列、序列间隔120 s,共10 d.两组在治疗前和治疗后（rTMS治疗后2周）均行ABC评分和脑电非线性分析检测.结果 两组治疗前的ABC评分值和脑电非线性分析参数均值（D2、PD2、Cx、LE、KE、ApEn）差异无统计学意义（P＞0.05）;治疗后治疗组的ABC评分和右额区脑电非线性分析参数PD2、Cx、均值比对照组显著增加,差异有统计学意义（P＜0.05）;而治疗组的左额区脑电非线性分析参数PD2、Cx、均值与对照组比较差异无统计学意义（P＞0.05）.结论 low-rTMS刺激右侧大脑半球（Broca区）对左半球脑梗死失语患者的语言有一定的康复作用.     

Left hemicranial hypoplasia in 2 patients with primary progressive aphasia

BACKGROUND: Primary progressive aphasia (PPA) leads to a gradual and relatively isolated dissolution of language function. The factors that determine the selectivity of the disease process remain unknown. We had speculated that PPA may occasionally arise as a tardive manifestation of genetic or acquired vulnerabilities involving the language network of the brain. OBJECTIVE: To explore predisposing factors for PPA. RESULTS: In 2 patients, PPA developed with a background of mild left hemicranial hypoplasia. CONCLUSION: In keeping with other observations of PPA in patients with dyslexia and childhood injury to the left temporal lobe, these 2 patients support the contention that some cases of PPA may arise in settings where the language network has become a locus of least resistance.