Biomedical subjects

E De Renzi

Publications and source records attributed to E De Renzi.

At least 19 recordsLinked to original sources

PubMed1992

Proper name anomia.

Following a left thalamic infarct, a patient showed a marked impairment in retrieving person proper names in response to faces and to verbal description, despite being able to provide precise information about the persons he could not name and to point to their photograph when the name was provided by the examiner. The patient was also impaired in generating proper names, but could easily retrieve common names as well as geographical names and names of monuments. It is hypothesized that the arbitrary nature of the link between proper names and their referents makes access of phonological forms from the semantic store particularly labile. In agreement with this interpretation is the patient's inability to recall telephone numbers and to learn semantically arbitrary paired associates.

Aged↗

PubMed1992

The incidence of the grasp reflex following hemispheric lesion and its relation to frontal damage.

The grasp reflex and related prehensile phenomena were investigated in two studies. In Study 1, 491 patients consecutively admitted to the neurological wards of our department were tested with a standardized procedure. Grasping was found in 8% of brain-damaged patients and occurred predominantly in patients with single (14 cases) or multiple (10 cases) hemispheric lesions, accompanied by stable neurological symptoms. The locus of the lesion was either in the frontal lobe or in the deep nuclei and subcortical white matter. Grasping never occurred when the disease was confined to the retrorolandic regions. Study 2 was designed to identify the frontal structures responsible for grasping. Forty-four patients who either showed grasping or had CT scan documentation of frontal damage were investigated. Grasping was found in 70% of patients who had involvement of the medial areas and was always associated with damage to the cingulate gyrus; the supplementary motor cortex was less consistently encroached upon. It also occurred following damage to the lateral motor and premotor areas, but only in 26% of cases. A few patients with grasping had deep lesions. The clinical analysis of the symptom showed that it usually affected both hands, even when the lesion was unilateral, and that in most patients it did not manifest itself as a forced phenomenon, but could be modified by will, although it showed up again as soon as the patient's attention was diverted. Groping was more rarely found and the so-called grasp reaction was unusual. No hemispheric asymmetry in the occurrence of this set of phenomena was apparent.

Brain Diseases↗

PubMed1991

Apperceptive and associative forms of prosopagnosia.

Three prosopagnosic patients were given four face tests, two perceptual (an unknown face identification test and an age estimation test) and two also implying memory (a familiarity check test and a famous face recognition test). The patients' performance was assessed with reference to the score distribution of the normal population. A patient was found to fail both perceptual and mnestic tests, without any noticeable difference between them. Also the second patient had poor scores on both kinds of tests, but his impairment was significantly greater on the perceptual ones. The third patient, on the contrary, showed no perceptual deficit and only failed the mnestic tests. His inability to recognize the individuality of an item among members of the same category was strictly confined to faces and never present for other classes of stimuli (cars, coins, personal belongings). This finding is supportive of the thesis that in a few patients the deficit underlying prosopagnosia is face specific.

Adult↗

PubMed1991

The aphasic isolate. A clinical-CT scan study of a particularly severe subgroup of global aphasics.

This paper outlines the clinical and CT scan features of a subtype of global aphasia, characterized by an extreme loss of communicative abilities, verbal as well as nonverbal. Three to four weeks after a left hemisphere stroke, 17 patients were completely unable to communicate with people addressing them. Though there were differences in their willingness to interact with the environment, they were characterized by complete loss of speech output and by inaccessibility to any kind of message, whether given verbally or through gestures. Patients who survived were reassessed 6 and 12 mos later and half of them were still found in a state of complete communicative isolation. The remainder had somewhat improved, but remained globally aphasic. The attempt to find a CT scan basis for this picture was disappointing. Only 35% of patients had a lesional pattern in agreement with the traditional view that ascribes global aphasia to the involvement of Broca's and Wernicke's areas. The location of lesion in the other cases spanned from anterior cortical damage, to posterior cortical damage, to deep nuclei damage and none of the lesions that have been proposed to account for subcortical global aphasia was consistently observed.

Aged↗

PubMed1990

Developmental dysmnesia in a poor reader.

A 22-yr-old subject with moderate developmental dyslexia experienced poor memory from an early age. In spite of normal intelligence he had great difficulty in learning historical and geographical names, mathematical formulae, poems and songs, and verbal series such as the letters of the alphabet and the months of the year. His recognition of familiar faces was also faulty at times. A battery of memory tests confirmed a moderate deficit of verbal as well as visual memory, whereas spatial memory was preserved. Other cognitive functions were intact, except for a mild reading disability. No evidence of brain pathology was provided by his history, neurological examination and CT scanning.

Adult↗

PubMed1989

Right posterior brain-damaged patients are poor at assessing the age of a face.

The ability to order unknown faces by age was investigated in right and left brain-damaged patients, divided into posterior and non-posterior groups on the basis of CT scan findings. A face recognition test and a figure ground discrimination test were also given. All three tests were affected by brain damage, but their sensitivity to the locus and side of lesion varied. While no hemispheric difference was found on the figure ground discrimination test, the face age test significantly discriminated patients with right posterior injury from any other brain-damaged group. The face recognition test occupied an intermediate position, with right posterior patients significantly impaired in comparison with right non-posterior patients and marginally impaired with respect to left posterior patients. Aphasia did not affect the performance of left brain-damaged patients on any of the tests. The findings are interpreted as evidence that damage of the right posterior hemisphere areas disrupts the structural encoding of visual information. Four prosopagnosic patients were also tested. Only those showing signs of apperceptive agnosia failed on the face age test.

Age Factors↗

PubMed1989

Space exploration with and without the aid of vision in hemisphere-damaged patients.

Space exploration carried out under visual control and in its absence (blindfolded condition) was investigated in 20 RBD patients, 10 LBD patients and 20 normal controls with a modified version of Chedru's test (pressing the keys of a keyboard). Conventional tests for visual hemi-inattention permitted to classify RBD patients in a group with visual neglect (RBD VN+) and a group without visual neglect (RBD VN-). On the visual version of the test both RBD groups showed a preference for pressing the keys ipsilateral to the lesion side, but this tendency was more marked in the RBD VN+ group than in any other brain-damaged group. On the tactile version of the test only RBD VN+ patients showed a gradient favouring the pressing of the ipsilateral half of the keyboard. This ipsilateral preference was, however, significantly less marked than that found when the performance was assisted by vision. No relation between neglect in the blindfolded condition and tactile extinction was found. The nature of space exploration in the absence of vision is discussed and the existence of tactile neglect is questioned.

Attention↗

PubMed1989

Attentional shift towards the rightmost stimuli in patients with left visual neglect.

In a search task where four letters were displayed to the right of a central fixation point, right brain-damaged patients with visual neglect showed the fastest response when the target was at the rightmost position and progressively slower responses as it moved towards the center of the display. This finding confirms Kinsbourne's claim that in visual neglect an important role is played by the magnetic attraction that the extreme end of the right structured space exerts on the patient's attention.

Adult↗

PubMed1989

Auditory neglect.

Auditory neglect was investigated in normal controls and in patients with a recent unilateral hemispheric lesion, by requiring them to detect the interruptions that occurred in one ear in a sound delivered through earphones either mono-aurally or binaurally. Control patients accurately detected interruptions. One left brain damaged (LBD) patient missed only once in the ipsilateral ear while seven of the 30 right brain damaged (RBD) patients missed more than one signal in the monoaural test and nine patients did the same in the binaural test. Omissions were always more marked in the left ear and in the binaural test with a significant ear by test interaction. The lesion of these patients was in the parietal lobe (five patients) and the thalamus (four patients). The relation of auditory neglect to auditory extinction was investigated and found to be equivocal, in that there were seven RBD patients who showed extinction, but not neglect and, more importantly, two patients who exhibited the opposite pattern, thus challenging the view that extinction is a minor form of neglect. Also visual and auditory neglect were not consistently correlated, the former being present in nine RBD patients without auditory neglect and the latter in two RBD patients without visual neglect. The finding that in some RBD patients with auditory neglect omissions also occurred, though with less frequency, in the right ear, points to a right hemisphere participation in the deployment of attention not only to the contralateral, but also to the ipsilateral space.

Auditory Perceptual Disorders↗

PubMed1989

[Agnosia].

The term agnosia defines an impairment of stimulus recognition, limited to one modality and not explainable in terms of sensory deficits or general mental deterioration. Visual object agnosia refers to the inability to recognize objects and prosopagnosia to the failure to recognize faces that are well familiar to the patient, when stimuli are visually perceived. Both deficits may appear in an apperceptive form, where it is the internal and external structure of the stimulus to be unrecognized and an associative form where the patient achieves a good percept, but cannot assign it a meaning. Apperceptive forms are preferentially associated with bilateral occipital damage, object associative agnosia with left occipital damage and associative prosopagnosia with right occipital damage.

Agnosia↗

PubMed1988

The executive and ideational components of apraxia.

Fifty six left brain-damaged (LBD) patients and 38 right brain-damaged (RBD) patients were requested to perform two measures of praxis using the hand ipsilateral to the side of lesion. One task required the accurate imitation of actions made by the examiner and taxed executive abilities; the other task required the patient to pantomime the use of objects that were shown, but not handed, and it also involved an ideational component, i.e., the evocation of gestures. The cut-off point discriminating a normal from a pathological performance was set at the level of the poorest score found in 60 control patients. On both tests apraxia was found to be associated primarily with left brain-damage. However, while on the use of objects test practically only LBD patients failed, on the imitation test there was also a sizeable proportion of RBD patients who showed a mild apraxia. When the performance on the two tests was contrasted, there were as many LBD patients as RBD patients who scored remarkably lower on movement imitation than on pantomiming the use of objects, whereas the opposite dissociation was found almost exclusively in LBD patients. We infer from these data that the left hemisphere dominance for praxis is more marked at the ideational stage and that there is also a minor right hemisphere participation in the control of the executive stage of gesture.

Apraxias↗

PubMed1988

Ideational apraxia.

Ideational apraxia was investigated in 20 left brain-damaged patients with tests requiring the demonstration of how objects are used. On a multiple object use test the most frequent errors were those of omission, misuse and mislocation, while sequence errors were rare. Patients also failed on a single object use test, which showed a correlation of 0.85 with the multiple object use test. Neither of these tests was significantly correlated with an ideomotor apraxia test (imitation of movements). Ideational apraxia was frequently, but not exclusively, associated with damage to the left posterior temporoparietal junction. These findings support the view that ideational apraxia is an autonomous syndrome, linked to left hemisphere damage and pertaining to the area of semantic memory disorders rather than to that of defective motor control.

Apraxias↗

PubMed1987

The incidence of aphasia and global aphasia in left brain-damaged patients.

Two hundred and twenty three right-handed patients consecutively admitted to the wards in a 21-month period for a left-sided cerebrovascular disease were examined 15 to 30 days after the stroke for the presence of aphasia. Twenty-seven of them could not be assessed. Of the remaining 196, 108 (55.1%) were aphasic. The incidence of global aphasia (43%) in the latter group was higher than in previous studies. Based on CT-scan data it was associated in 32% of patients with a deep lesion and only in 53% with an antero-posterior cortical-subcortical lesion, contrary to what is traditionally assumed. There was no sex difference in the incidence and distribution of aphasia.

Acute Disease↗

PubMed1987

Semantic amnesia with preservation of autobiographic memory. A case report.

A 44-year-old woman showed, following an episode of encephalitis, an impoverished knowledge of the meaning and attributes of words and their referents, in spite of intact command of grammatical-syntactic rules and preserved perceptual abilities. There was also a complete loss of the stock of notions she had acquired over her life and constituting the cultural background of a person, in contrast with normal memory for autobiographic events. The case is interpreted as an instance of semantic amnesia. MRI showed damage confined to the antero-medial part of the left temporal lobe.

Adult↗

PubMed1987

The pattern of neuropsychological impairment associated with left posterior cerebral artery infarcts.

We investigated the neuropsychological correlates of left posterior cerebral artery (LPCA) infarcts with a quantitative systematic approach and found a pattern of impairment extending well beyond the classical syndrome of alexia without agraphia. Sixteen consecutive patients with CT scan evidence of an infarct confined to the territory of LPCA were given a battery of tests assessing the following abilities. (1) Reading and writing; (2) naming and pointing to colours; (3) naming the same 30 objects on visual (objects and coloured photographs), tactile and verbal presentation; and (4) verbal memory. These tests were administered to large control samples and the performance of LPCA patients was considered pathological if it fell below the score of the last or second to last control patient. Seventy five per cent of PCA patients had alexia without agraphia. Although a lesion of the CT scan slice where the pineal is represented appeared to be crucially associated with alexia, the severity of the disorder increased when contiguous upper or lower slices were also involved. Not only colour anomia, but also object and especially photograph anomia could almost always be shown in alexics and were highly correlated with the degree of the reading impairment. The naming deficit was also present when items were presented in the tactile and verbal modality, in spite of the integrity of the oral language areas. Every right-handed patient, alexic as well as nonalexic, was impaired on at least two of the three verbal memory tests and most on all of them. The findings are discussed in terms of the anatomofunctional mechanisms subserving verbal memory and the transmission of visual information to the speech areas.

Cerebral Arteries↗

PubMed1987

Bilateral paramedian thalamic artery infarcts: report of eight cases.

Eight consecutive patients with CT scan evidence of a bilateral infarct in the territory of the paramedian thalamic artery are reported. In seven cases the infarct also extended to the territory of the polar artery. The main symptoms were: disorder of vigilance which cleared in a few days, and hypersomnolence which lasted longer and in two patients was still present a year later; amnesia, detectable clinically in four patients and only with tests in two patients, which persisted in one patient for three years; changes of mood and bulimia present in five and four patients respectively; and vertical gaze paresis in five patients. Only one patient died, and in the remainder the symptoms tended to subside, but none of the patients who could be followed-up for a year returned to normal behaviour. Clinical and CT scan correlations pointed to the mammillo-thalamic tract as the structure whose damage was responsible for the memory disorders.

Adult↗

PubMed1986

Prosopagnosia in two patients with CT scan evidence of damage confined to the right hemisphere.

Two patients developed a severe and long-lasting inability to recognize familiar faces (prosopagnosia) after a stroke, which was shown by CT scan to be confined to the right hemisphere. The area of softening involved the entire cortico-subcortical territory of distribution of the right posterior cerebral artery. These data suggest that in a few cases right occipito-temporal damage may be sufficient to produce prosopagnosia.

Aged↗

PubMed1986

Slowly progressive visual agnosia or apraxia without dementia.

Two patients manifested a progressive impairment of visuoperceptive abilities and one patient a progressive generalized apraxia, in the absence of dementia and oral language disorders. The disease started in the presenium and the follow-up was of five, two and half and two years, respectively. The relation of these clinical pictures to cases of generalized dementia and to cases with isolated, progressive aphasia is discussed.

Aged↗