121/196. Subcortical aphasia: two clinical-CT scan correlation studies. Two clinical-CT scan studies were undertaken in order to investigate the frequency and the characteristics of aphasia following strictly subcortical left hemisphere lesions. In Study 1, all patients whose CT scan, carried out within a given period, showed subcortical lesions in both hemispheres, were evaluated for presence and type of aphasia; conversely, in Study 2 the records of all patients referred to our aphasia Unit for language evaluation within a given period, were examined for presence of subcortical lesions on the CT scan. In Study 1 aphasia was found in two out of six patients. In Study 2 stabilized, strictly subcortical lesions of the left hemisphere were found in six out of 250 patients referred to the aphasia Unit; 4 out of 6 were aphasics. Closer scrutiny of the type of language disorder in the aphasics from both studies (N = 6) suggests the possibility of differentiating two types of defect: an atypical non fluent aphasia, sometimes associated with anterior capsular-putaminal lesions, and a mild fluent aphasia, sometimes associated with posterior capsular-putaminal lesions. ( info) |
122/196. Temporary neurological deterioration after extracranial-intracranial bypass. Five patients who experienced temporary neurological deterioration after extracranial to intracranial bypass procedures are reported in detail. These patients suffered transient ischemic attacks or more prolonged deficits usually of a different nature than the preoperative symptoms. All patients had a good outcome and the spells ceased; the neurological deficits improved within a maximum of 2 weeks. Obvious causes of deterioration such as intra- or extracerebral hematomas, occlusion of a previously stenotic vessel, or graft occlusion were ruled out by computed tomography and angiography in each case. Intraoperative causes of neurological deterioration such as anesthetic effect, hypotension, and temporary occlusion of the cortical vessel or sacrifice of its small branches were not likely to be the cause of the deficits because in each case, the patient awoke satisfactorily and deterioration occurred hours to days later. In each case, postoperative angiography showed good perfusion of at least one major division of the middle cerebral territory. Anticoagulation with heparin in three patients did not change the clinical course. In one patient who was not anticoagulated, embolism could have been responsible for a single prolonged ischemic event, but in the other patients thromboembolism does not seem likely to have been responsible for the deficits. The cause of the deterioration in these patients remains unexplained. We speculate that hyperperfusion of chronically ischemic brain tissue and shifts in the watershed region resulting from the new flow pattern after bypass grafting are two mechanisms that may have been of importance in the etiology of these deficits. ( info) |
123/196. Persistent Broca's aphasia after right cerebral infarction in a right-hander. A strongly right-handed man developed sudden mutism and left hemiplegia 2 days after a myocardial infarct. Evaluation 6 1/2 years later revealed persistent Broca's aphasia. There was no clinical, CT, or EEG evidence of left brain injury or disease. This case is another example of dissociation of cerebral dominance for speech and handedness. However, the severe and persistent language disorder is rare. The paucity of documented case reports supports the traditional view of strong interdependence of handedness and speech cerebral lateralization. ( info) |
124/196. aphasia with a left frontal interhemispheric hematoma. We studied a patient with transcortical motor aphasia resulting from a traumatic interhemispheric left frontal hematoma. The aphasia was caused by compression exerted by the hematoma on the left supplementary motor area, which is known to have a function in speech. This cause of a transcortical motor aphasia has not been described earlier. ( info) |
125/196. Non-paralytic motor disturbances and speech disorders: the role of the supplementary motor area. A right-handed patient with a lesion demonstrated by CT to involve the right medial frontal cortex is described. He exhibited a strong contralateral grasp reflex, motor perseveration and the presence of purposeful movements that appeared to be dissociated from conscious volition. In addition, there was a disorder of speech consisting of a lack of spontaneous speech production, with preserved ability to imitate. It is suggested that these disorders are due to damage to the supplementary motor area. ( info) |
126/196. "Late" recovery of the right ear dichotic score following cerebrovascular accident: a case report. Late recovery of the right ear score on a digit dichotic listening test was observed in a 45-yr-old female patient. The right ear score was at chance levels of accuracy through the ninth month post-onset of a cerebrovascular accident and then improved dramatically to 67% correct by month 12. Possible bases for this pattern of performance are discussed. ( info) |
127/196. Motor aphasia unaccompanied by faciobrachial weakness. Most patients with motor aphasia resulting from lesions of the left frontal opercular region have weakness of the right face and arm. We report a 43-year-old man who suffered mutism and agraphia unaccompanied by right-sided weakness after embolic infarction of Broca's area. ( info) |
128/196. Comparison of the performances of a fluent and a nonfluent aphasic on a pantomimic referential task. The pantomimic performances of a typical Broca's (nonfluent) and Wernicke's (fluent) aphasic were compared with each other and with four normal control subjects on a simple task of nonverbal referential communication. Both aphasic subjects demonstrated only about 50% accuracy in their pantomimic communication. Also, measures were obtained of the motoric fluency of the pantomimes of all subjects and comparisons were made between the fluent and nonfluent aphasics. These measures demonstrated distinct differences in the fluency patterns of the pantomimes of the two aphasic subjects similar to the differences in speech fluency which distinguish and characterize these two types of aphasia; that is, the fluent aphasic pantomimed fluently and like the control subjects and the nonfluent aphasic pantomimed nonfluently. The quantitative and qualitative similarities in the fluency patterns of the speech and the pantomimic behaviors of the aphasic subjects are discussed in terms of their implications for a definition of aphasia. ( info) |
129/196. An experimental analysis of auxiliary and copula verb generalization in aphasia. Two subjects with chronic Broca's aphasia were taught to produce third person singular auxiliary is in sentence contexts to determine if is production would generalize to untrained auxiliary is items and to copula is contexts. A single subject (ABAB) reversal design was employed. Results revealed that training a few exemplars of the present tense auxiliary is resulted in generalized responding to untrained auxiliary is and copula is plus predicate adjective items. Generalized responding to untrained copula is plus predicate nominative and locative items was marked by individual variability. Although auxiliary and copula is verb production was maintained on 2- and 6-week follow-up probes, transfer to spontaneous speech was negligible. The results were interpreted as providing partial support for the existence of a functional or generative response class between verbal auxiliary and the copula is verbs. ( info) |
130/196. A two-route model of speech production. Evidence from aphasia. Quantitative investigations of speech production deficits are reported in three aphasic patients. Two had impaired paraphasic performance in repetition tasks but relatively well preserved spontaneous speech (conduction aphasia). The other patient had impaired paraphasic spontaneous speech but intact repetition (transcortical motor aphasia). In repetition tasks which required active semantic processing the conduction aphasics were facilitated and the transcortical motor aphasic impaired; in tasks which required passive repetition the opposite pattern of dissociation was observed. These findings are accounted for within a two-route model of the speech production process. ( info) |