L.A. Vignolo

Oral Apraxia and Aphasia

Summary This study was undertaken in order to assess the frequency and to explore the role of oral apraxia in expressive disturbances of speech. Forty right brain damaged patients, 134 left brain damaged patients and 40 control patients were given an oral apraxia test and a limb apraxia test for intransitive movements. In the left hemispheric group the presence and quality of aphasia was assessed by means of a standard aphasia examination. On the oral apraxia test, the performance of the right hemispheric group was similar to that of the control group. All the left brain damaged patients who scored below the lowest score obtained by any of the right brain damaged patients were considered oral apraxic. A strong association was found between oral apraxia and phonemic-articulatory disorders of speech, the exceptions being mainly in the sense of a poorer verbal than praxic performance. However, severe oral apraxia was found in two non aphasic left brain damaged patients. When considered with respect to the clinical syndromes of aphasia, it was found that oral apraxia was a very common accompaniment of Brocas aphasia and of phonemic jargon aphasia, it was present in one third of conduction aphasics and it was usually absent in Wernickes aphasia. Oral apraxia was not uncommonly found to be independent of limb apraxia. Moreover, the majority of patients with severe oral apraxia and mild or no phonemicarticulatory disturbances did not show limb apraxia: therefore, one cannot argue that, in these cases, oral apraxia was part of a general praxic disturbance.

Localisation of Lesions in Aphasia: Clinical-CT Scan Correlations in Stroke Patients

Ninety right-handed patients with present or past evidence of aphasia following a stroke were given a standard language battery and a CT scan examination. Presence and type of aphasia were correlated with the location and extent of the CT scan lesion. Most of the findings were compatible with the traditional views about the localisation of lesions in aphasia (e.g., anterior lesions in nonfluent aphasias with good comprehension, posterior lesions in fluent aphasia, etc.). The possible explanations for some unexpected findings (e.g., purely anterior lesions in global aphasia, or purely deep lesions in Brocas aphasia) are discussed. It is stressed that in establishing clinico-CT scan correlation, careful consideration must be given to the fact that both aphasia and the underlying lesion evolve with time.

Phonemic Identification Defect in Aphasia

Eight-four right-handed patients with unilateral hemispheric damage (50 aphasics, 12 non-aphasic left brain-damaged and 22 right brain-damaged patients) and 53 control patients without cerebral lesions were given a test of phoneme identification which examined the Ss ability to identify the acoustic boundary between the two phonemes, /d/ and /t/, expressed in terms of voice-onset time (VOT). Phonemic identification defect (PID), defined with reference to the performance of the control group, was found to be virtually limited aphasics; in over 70 per cent of them, the identification of the boundary zone between voiced and voiceless consonants along the VOT continuum was either impossible or abnormal, While neither the fluency - nonfluency dimension of speech nor the level of comprehension seemed to be crucially associated with PID, some evidence pointed to disordered phonemic output as to one dimension of aphasia that is specifically related to it.

The Influence of Aphasia and of the Hemispheric Side of the Cerebral Lesion on Abstract Thinking

Summary A modified version of Weigl Sorting Test which allows 5 criteria of classification was administered to 40 control patients, 40 right brain-damaged patients, 22 left non-aphasic brain-damaged patients and 45 aphasics. The performance of the 4 experimental groups was analyzed by means of co-variance analysis, independent variables being age, years of schooling and RT. Right and left non-aphasic brain-damaged patients performed not differently from control patients on Weigl test, while the mean score of the aphasic group turned out to be about one half of that of the control group. The analysis yielded the same results also when the score obtained by the patients on a general intelligence test (Ravens P. M. 1938) was introduced as an additional independent variable. The score obtained by aphasics on Weigl test was found to correlate highly with an auditory verbal comprehension score, while no significant correlation was found between Weigl score and either a visual naming or an ideomotor apraxia score. Patients with typical “amnesic” aphasia were not found to perform the test more poorly than patients with typical Wernickes or Brocas aphasia. In conclusion, these data indicate that Weigl test is not sensitive to the presence of cerebral damage per se while it is highly sensitive to the presence of left (dominant) hemisphere lesions associated with aphasia. The evidence pointing to a specific defect of “abstract thinking” in aphasics may be interpreted as the consequence of a disruption of “inner language” in these patients; however, an alternative view may be advanced, viz., that the same areas subserving linguistic activities in the left hemisphere are also specialized in carrying out intellectual tasks of a symbolic nature.

Contrasting behavior of right and left hemisphere-damaged patients on a discriminative and a semantic task of auditory recognition.

Summary One hundred and one patients with unilateral hemispheric illness (41 right, 60 left hemisphere-damaged patients) and 49 control patients without cerebral lesions were given two non-verbal auditory recognition tasks, of which one (the Meaningless Sounds Discrimination Test) was intended to test the ability to discriminate the exact acoustic pattern of sounds, while the other (the Meaningful Sounds Identification Test) was intended to test the ability to identify the exact meaning of sounds. Patients were also given tests of visual discrimination (the Profile-Front Face Test), auditory verbal comprehension (the Token Test) and vigilance (simple visual reaction times). It was found that the right hemisphere-damaged patients were specifically impaired on the Meaningless Sounds Test, while the left hemisphere-damaged were specifically impaired on the Meaningful Sounds Test. This “double dissociation” was found to be highly significant. The Meaningless Sounds Test behaved like the visual discrimination test with respect to the side of the lesion, but, unlike this, it was not sensitive to the presence of homonimous visual field defects. Variations of vigilance apparently had no differential influence on the auditory recognition performances. Impairment on the Meaningful Sounds Test in left hemisoheredamaged patients was confined to aphasics and was highly correlated with the severity of the auditory verbal comprehension defect. Patients whose auditory recognition defect was strictly confined to either the Meaningless or the Meaningful Sounds Test were singled out. All 8 patients in the former group suffered from lesions of the right hemisphere and all 22 patients in the latter group suffered from lesions of the left hemisphere and aphasia. The former were significantly more impaired than the latter on the visual discrimination task, while the reverse occurred with tasks implying the semantic decoding of visual stimuli and with Weigl’s test of conceptual thought. The implications of these findings are discussed.

Brain lesions associated with oral apraxia in stroke patients: A clinico-neuroradiological investigation with the CT scan ☆

Abstract Forty-four right-handed patients who had sustained a cerebro-vascular accident involving the left hemisphere were given a quantitative test of Oral Apraxia (OA) 21 to 60 days post-stroke, and a CT scan more than 21 days post-stroke (i.e., after the lesion was stabilized). The QA test examined the patients ability to imitate simple oral gestures. A comparison of the CT scan findings for patients with and without OA indicated that the crucial areas, lesions of which impair the ability to carry out simple oral gestures on imitation, include the frontal and central opercula, the anterior insula and a small area of the first temporal convolution of the left hemisphere.

Phonemic and lexical errors in fluent aphasia: Correlation with lesion site

Abstract Comparison of the CT scan findings in two matched groups of fluent aphasics—i.e., 10 with predominantly phonemic speech errors on a naming task and 11 with predominantly lexical errors—showed that phonemic disorders of speech were associated with lesions nearer to the sylvian fissure, while lexical disorders of speech were associated with lesions farther from the sylvian fissure. Two patients in each group had purely deep lesions. The possible significance of these findings is discussed.

Impaired Recognition of Meaningful Sounds in Aphasia

Summary Ninety-six right-handed patients with unilateral hemispheric damage (51 aphasics, 16 non-aphasic left brain-damaged and 29 right brain-damaged patients) and 35 control patients without cerebral lesions were given a sound recognition test requiring the identification of 10 meaningful sounds or noises. The patient was asked to listen to each sound and to indicate which of 4 pictures shown to him represented its natural source. The test allowed both a quantitative score (n° of correct responses) and a qualitative score (n° of acoustic , semantic or odd errors). It was found that while non-aphasic left and right brain-damaged patients performed virtually like normal controls on the test, a significant 348 H. Spinnler and L.A. Vignolo proportion of aphasics (about 25%) fell below the normal cut-off score. The performances of patients with Wernickes aphasia were particularly poor. In the entire aphasic sample, sound recognition scores appeared to correlate significantly with scores of auditory verbal comprehension (r s = .56). When aphasics were compared to non-aphasic patients with respect to the quality of performance, aphasia was found to be associated more with semantic than with acoustic errors. These findings seem to indicate that the impaired recognition of meaningful sounds, characteristic of aphasics, is due to a great extent to the inability to associate the perceived sound to its correct meaning, rather than to a merely acoustic-discriminative defect. The hypothesis is advanced that this semantic-associative disorder is the common factor underlying both the sound recognition and the auditory language comprehension defects, and that it may manifest itself also in other areas of the aphasics behavior.

Visual Figure-Ground Discrimination in Patients With Unilateral Cerebral Disease

Summary The purpose of this study was to evaluate the influence of aphasia, of visual field defects and the hemispheric side of the lesion on Gottschaldt Hidden Figure Test. This test was administered to 95 right handed patients with unilateral lesions of the cerebral hemispheres and to 40 control patients. The brain-damaged sample was divided into sub-groups according to the side of the lesion and the presence/absence of visual field defects and (within the left hemisphere group) of aphasia. Scores were compared by means of co-variance analyses, concomitant variables being age, years of schooling and visual reaction times (considered as a measure of the severity of the lesion). Il was found that visual field defects did not significantly affect the test scores. In contrast, poor performances were significantly associated with the presence and severity of aphasia. Right brain-damaged patients performed not differently from left brain-damaged patients, considered as one group. However, they did significantly worse than non-aphasic left brain-damaged patients. These were the only group whose mean score was virtually as good as that of the control group. These findings seem to indicate that poor visual figure ground discrimination (as tested by Gottschaldt test) in brain-damaged patients may be due to the impairment of at least two specific abilities, i.e. language (or some intellectual factor closely related to it) and some other ability (perhaps a visuo-spatial ability), preferentially subserved by the right hemisphere.

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.