Transcortical Aphasia Research Articles

Creutzfeldt-Jakob disease with mixed transcortical aphasia: insights into echolalia.

Aphasia is a common manifestation of Creutzfeldt-Jakob disease (CJD), and investigation of the linguistic disorders of CJD patients may provide insights into the neurobiological mechanisms of language and aphasia. We report an autopsy-confirmed case of CJD in which the presenting symptom was change in language abilities. The patient ultimately evidenced mixed transcortical aphasia (MTA) with echolalia. Disruption of frontal-subcortical circuits with environmental dependency accounts for the symptoms in MTA, including intact repetition and echolalia. Observation in this patient and a review of the literature suggest that frontal-subcortical circuit dysfunction may contribute to the syndrome of echolalia. This hypothesis offers an alternative explanation to "isolation" of the speech area as the cause of MTA.

Creutzfeldt-Jakob Disease with Mixed Transcortical Aphasia: Insights into Echolalia

Aphasia is a common manifestation of Creutzfeldt-Jakob disease (CJD), and investigation of the linguistic disorders of CJD patients may provide insights into the neurobiological mechanisms of language and aphasia. We report an autopsy-confirmed case of CJD in which the presenting symptom was change in language abilities. The patient ultimately evidenced mixed transcortical aphasia (MTA) with echolalia. Disruption of frontal-subcortical circuits with environmental dependency accounts for the symptoms in MTA, including intact repetition and echolalia. Observation in this patient and a review of the literature suggest that frontal-subcortical circuit dysfunction may contribute to the syndrome of echolalia. This hypothesis offers an alternative explanation to “isolation” of the speech area as the cause of MTA.

Behavioral and neoronal changes during treatment of mixed transcortical aphasia: A case study

The development of language mechanisms outside the traditional language regions is evidenced by the case of K.S., a patient with chronic mixed transcortical aphasia, that is, good repetition performance compared to all other language abilities. The aphasia was caused by an infarction of the left a. carotis interna that completely destroyed the left perisylvian language region and adjacent structures. Five years post onset the patient underwent intensive aphasia therapy. In the treatment setting chosen, both speech production and comprehension abilities improved as demonstrated by adequacy and reaction time scores. It is argued that the behavioral changes observed are likely to be due to (a) newly acquired communicative strategies and (b) neuronal changes within K.S.'s brain. The behavioral changes are explained in terms of strengthening of synaptic connections and formation of Hebbian cell assemblies corresponding to words.

Sigmund Freud and the diagram-maker school of aphasiology

Published 100 years ago, Freud's monograph on aphasia, Zur Auffassung der Aphasien, is an incisive analysis of the so-called diagram-makers, those aphasiologists who would reduce brain and language to simple schemes of circumscribed cortical centers linked by unidirectional subcortical pathways. Chief architects of the diagram-maker school were Wernicke and Lichtheim, and their formulations of conduction aphasia and the transcortical aphasias were particular targets of Freud's trenchant criticism. Freud argued against functional differentiation within left hemisphere perisylvian language regions, and he suggested that traditional aphasic syndromes were artifacts of lesions that included cortical language regions and deeper white matter pathways not directly involved with language. He provided an innovative classification of aphasia based on types of associations presumed to be affected. Freud, however, failed to adduce new clinical or pathological observations; he was perhaps unnecessarily harsh in challenging authorities in the field of aphasia; and his theory had to compete with a straightforward and already entrenched anatomical view of language representation. Despite Freud's lucid argumentation, his carefully crafted monograph was never widely noted.

The influence of infarct location on recovery from global aphasia

Abstract The influence of the anatomical location of the cerebral infarcts causing global aphasia on recover was studied on a sample of 54 global aphasics with first-ever strokes imaged by computerized tomography. Lesions causing global aphasia could be grouped into five types, with different outcomes: type 1, large pre and postrolandic middle cerebral artery (MCA) infarcts had a very poor prognosis, type 2 (prerolandic), type 3 (subcortical), type 4 (parietal) and type 5 (double frontal and temporal lesion) had a variable outcome, improving in general to Broca's or transcortical aphasia. Some cases with type 2 and 3 infarcts recovered completely. The best prognosis was observed in the subcortical group. Age and skull asymmetries had a minor influence on this pattern of evolution. Global aphasics have a variable potential for recovery, that should be taken into consideration when evaluating possible treatments for this severe language disorder.

Double infarction in one cerebral hemisphere

Thirty-two patients whose first stroke was due to double infarct in one cerebral hemisphere were identified among 1,911 consecutive patients from the Lausanne Stroke Registry. The double infarct involved territories of the superficial middle cerebral artery, superficial posterior cerebral artery, lenticulostriate, anterior choroidal artery, or borderzone. The most common combination involved territories of the anterior middle cerebral artery plus the posterior middle cerebral artery. In the patients with the double infarct, the prevalence of potential cardiac sources of embolism (19%) was similar to that found in the registry in general, but the double infarct was closely associated with tight (greater than or equal to 90% of the lumen diameter) stenosis or occlusion (75%) of the internal carotid artery. The most common neurological picture mimicked large infarction in the middle cerebral artery territory, but nearly half of the patients with double infarct in one cerebral hemisphere had a specific clinical syndrome, which was not found in the 1,879 remaining patients from the registry, including hemianopia-hemiplegia (in 6), acute conduction aphasia-hemiparesis (in 2), and acute transcortical mixed aphasia (in 6), in relation to characteristic combinations of infarcts. These unique clinical and etiological correlates warrant the recognition of double infarct in one cerebral hemisphere from other acute ischemic strokes.

TRANSCORTICAL APHASIA: IMPORTANCE OF THE NONSPEECH DOMINANT HEMISPHERE IN LANGUAGE REPETITION

While a relative preservation of repetition in acute transcortical aphasia (TA) has usually been associated with the functional integrity of the speech dominant (left) perisylvian area, recent amytal data (Bando et al., 1986) have suggested a fundamental role of the nondominant (right) hemisphere in language repetition. The neuroradiological correlates of repetition were studied in a consecutive series of 21 patients with acute TA. A similar frequency of either perisylvian or extraperisylvian pathology was found. In 2 patients with perisylvian pathology, the injection of amytal in the hemisphere contralateral to the lesion abolished repetition. Positron emission tomography (PET) in another patient revealed marked hypometabolism over the entire left cortical mantle ipsilateral to a basal ganglia lesion, suggesting that preserved repetition was carried out by right hemisphere structures. This was confirmed in a second patient with left extraperisylvian pathology, in whom a second lesion in the right hemisphere resulted in impaired repetition. These findings suggest that the spared contralateral hemisphere may subserve residual repetition in some transcortical aphasic patients with a lesion within or outside the speech-dominant perisylvian area.

Primary progressive aphasia with focal neuronal achromasia

We describe the clinical, radiologic, neuropsychological, and neuropathologic features of a 69-year-old man with a 3-year history of progressive transcortical expressive aphasia. Neuropsychological testing showed progressive dysfunction of expressive language. Neuropathologic examination demonstrated focal cortical degeneration involving the left superior frontal gyrus, with swollen achromasic neurons and no evidence of Alzheimer's disease, Pick's disease, Creutzfeldt-Jakob disease, Lewybody disease, or other dementing disorders. This case adds to the known heterogeneity of the underlying pathology of patients with primary progressive aphasia.

Language disturbances from mesencephalo-thalamic infarcts

The authors report the cases of two patients with CT-documented paramedian mesencephalo-thalamic infarcts, showing language disturbances. The first patient showed a non fluent, transcortical motor-like aphasia, the other had a fluent but severely paraphasic language disorder. The CT study disclosed that it was the dorso-median thalamic nucleus that was mostly involved in both cases. These findings agree with a few previous pathological studies suggesting that the paramedian thalamic nuclei, particularly the dorso-median nucleus may play some role in language disturbances. However the anatomical basis for thalamic aphasia remains speculative, taking into account the importance of cortical connections in the origin of subcortical neuropsychological disturbances.

Mixed Transcortical Aphasia: Clinical Features and Neuroanatomical Correlates

This paper reports the clinical features of 2 patients affected by mixed transcortical aphasia. Both of them had extensive damage of the left hemisphere. Cerebral blood flow measurement showed a marked decrease in left-hemisphere flow. In particular, speech areas were found to be morphologically and functionally damaged. The present findings, together with a critical review of the literature, served as a starting point for a discussion of linguistic features, diagnostic criteria and classical neuroanatomical interpretation of mixed transcortical aphasia. The possible contribution of the right hemisphere in determining this aphasic syndrome is suggested.

Sprachveränderungen bei der Demenz

This review analyzes the spectrum of language deficits commonly encountered in dementia. A specific communication profile is found in dementia of the "cortical" type, such as Alzheimer's disease. With advancing disease lexical, comprehension and pragmatic functions deteriorate, whereas syntax and phonology tend to be preserved. This pattern bears some resemblance to aphasia types like transcortical and Wernicke's aphasia, however, a much broader range of communicative functions is impaired in Alzheimer's disease than in aphasia. Differentiation of dementia and aphasia, especially in elderly patients requires careful neuropsychological assessment of language, memory and other psychological functions. "Subcortical" dementia commonly presents with dysarthria as the leading symptom and linguistic impairment is rarely of crucial importance until late stages. Thus, the interetiologic dissociation of language and speech impairment can be used for dementia differentiation. Aphasia batteries are not sufficient to comprehend the range of language deficits in demented patients. Testing the communication impairment in dementia requires specific tasks for spontaneous speech, naming, comprehension, reading, writing, repetition and motor speech functions. Tasks for verbal learning and metalinguistic abilities should also be performed. Language deficits are frequent initial symptoms of dementia, thus language assessment may be of diagnostic relevance. Many data support the concept that the communication deficit in dementia results from a particular impairment of semantic memory.

Mixed transcortical aphasia without anatomic isolation of the speech area.

We report two patients with mixed transcortical aphasia following left frontal lobe infarctions. Although there was no evidence of anatomic isolation of the speech area on computed tomograms or magnetic resonance imaging scans, single-photon emission computed tomography in one case demonstrated diminished blood flow over the left parietal convexity suggestive of "functional isolation" of the posterior perisylvian language zone.

Mixed transcortical aphasia from demyelinating disease: Neuropsychologic, MRI, and neuropathologic data

Mixed transcortical aphasia from demyelinating disease: Neuropsychologic, MRI, and neuropathologic data

Mixed Transcortical Aphasia in Nonfamilial Dysphasic Dementia

The neurolinguistic and cognitive profiles of a patient with nixed transcortical aphasia and non-familial dysphasic dementia associated with progressive, left perisylvian involution are presented. This clinicopathological entity has recently been shown to be an example of a novel class of intrinsic, focal cortical degenerations with sparing of the basal forebrain. The characteristics of the aphasia were unusual. There where occasional and verbal paraphasic errors, but no completion phenomenon, embellishment or significant ecliolalia. Evidence of a generalized lexical disruption was found on detailed anayanalysis of residual abilities it reading, writing and spelling. A newly described from of non-lexical repetition was present, resulting in the patient's inability to correct syntactical and semantic errors. Affective prosodic repetition was intact. A combined paraphasic wordproduction and semantic anomia was found. These observations combined with evidence process of evolving region-specific cognitive impairments suggest that the pathological resulted in a relative disconnection of integral frontal and parieto-occipital areas from adjacent perisylvian anguage zones.

Young adult stroke: neuropsychological dysfunction and recovery.

Etiology, neuropsychological deficits, aphasia type, and recovery were retrospectively studied in 254 young adults with stroke. Cardiac embolism was the most common cause of stroke in patients younger than 40, while atherosclerosis was the most frequent etiology among those aged 41-50 years. In 166 aphasic patients, Broca's aphasia was the most common while Wernicke's and transcortical aphasias were rare. Compared with an older aphasic population, young patients had significantly more nonfluent aphasias and fewer comprehension deficits. These differences were related to stroke localization: the majority of infarcts localized by computed tomography in 37 patients involved either the entire middle cerebral artery territory or its superior or deep branches, explaining the preponderance of nonfluent aphasia. Prognosis of aphasia in our patients was better than has been reported for non-age-selected aphasia populations. Roughly one third of our patients recovered completely, one third improved, and one third had an unresolved language deficit. Complete recovery and significant improvement were observed even greater than 6 months after stroke. In some patients, recovery was much better than might have been predicted from lesion site and size depicted on computed tomograms.

ACUTE TRANSCORTICAL MIXED APHASIA

Four of 1,200 consecutive patients with their first stroke showed acute transcortical mixed aphasia (TMA) characterized by nonfluent speech with impaired naming, semantic paraphasias, echolalia, impaired comprehension, good repetition, reading, and writing on dictation. All 4 had left internal carotid artery (ICA) occlusion with ipsilateral anterior pial territory infarction (precentral-central sulcus artery territory) and watershed infarction between the middle and posterior cerebral artery territories, which spared and 'isolated' the perisylvian speech areas. Although rare, acute TMA is highly suggestive of infarction due to ICA occlusion, in that it is probably related to simultaneous embolism (anterior pial infarction) and haemodynamic insufficiency (posterior watershed infarction).

Mixed transcortical aphsia. On relative sparing of phonological short-term store in a case

A case of Mixed Transcortical Aphasia is reported. The patient showed completely impaired verbal comprehension and speech production, with preservation of automatic speaking and singing; repetition was relatively spared. A detailed study of word and nonword repetition is reported, in order to demonstrate that the patient's residual repetition ability is based on relative sparing of short-term phonological store.

Aphasia following right thalamic hemorrhage in a dextral

A 74-year-old, right-handed woman with a right thalamic hemorrhage and aphasia is described. Sequential neurologic examinations and aphasia testing were carried out during a 1-year period and the results are reported. The patient exhibited a language deficit resembling a transcortical aphasia in the acute stage. Reduced spontaneous speech, fading voice volume, fluent verbal output with paraphasia, anomia, and a mild comprehension difficulty were present. Repetition was good. At 1 year postonset, the primary language problem exhibited by the patient was in object naming, all other components of the original language deficit having shown good recovery. This is the first reported case of right thalamic involvement in speech/language in the absence of personal and familial sinistrality.

A case of mixed transcortical aphasia following drug overdose

ABSTRACTA case is presented of a 35‐year‐old, right‐handed man who exhibited a range of clinical features indicative of mixed transcortical aphasia subsequent to a heroin overdose. The findings of a comprehensive language evaluation, neurological assessment and neuroradiological examination are described and discussed. The major feature of the patient's language disorder was the relative loss of the voluntary aspects of language (eg spontaneous speech; the ability to initiate or actively participate in conversations) compared to the preservation of the automatic, non‐volitional components of language (eg repetition; rules of syntactic agreement; completion phenomena; and verbal automatisms). It was concluded that the features of mixed transcortical aphasia demonstrated were most likely the result of anoxic changes in the arterial borderzone occurring secondary to the drug overdose.

The syndrome of unilateral tuberothalamic artery territory infarction.

The study of 3 personal cases and 5 published cases of unilateral infarct limited to the territory of the tuberothalamic artery suggests that this syndrome should be differentiated from the other thalamic syndromes. The onset is usually sudden, with moderate contralateral weakness. Sensory changes may be present but remain mild. The patients are apathetic, show perseveration and may be disoriented. In left-sided infarcts, transcortical aphasia, verbal and visual memory impairment and sometimes acalculia are found. In right-sided infarcts, hemispatial neglect, visual memory impairment and disturbed visuospatial processing are common. A decreased level of consciousness, disturbed ocular movements, severe motor weakness and delayed abnormal movements do not occur. Involvement of the ventral lateral and dorsomedial nucleus with sparing of the intralaminar nuclei, posterolateral formation and upper midbrain may explain this picture. The fact that the tuberothalamic artery arises from the posterior communicating artery, which often receives its supply from the carotid system, further justifies considering unilateral tuberothalamic infarcts as a syndrome.