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G Gainotti

Publications and source records attributed to G Gainotti.

At least 37 records · Page 2Linked to original sources
PubMed1997

Naming deficit for non-living items: neuropsychological and PET study.

We report a patient with progressive left hemisphere atrophy who presented a lexical retrieval deficit more pronounced in naming non-living items than in naming living items. Word frequency and familiarity strongly influenced the performance, but the dissociation persisted when the items were controlled for these factors. In addition, the prevalent deficit for non-living items in respect to living items could be confirmed in tasks where other patients presented the opposite pattern. A PET study showed a significant hypometabolism in the left hemisphere regions suggesting that, at variance with living deficit which is observed in patients with bilateral lesions, non-living deficit is produced by unilateral left hemispheric lesions. This patient confirms that living and non-living categories may dissociate and that distinct neural systems subsume their knowledge.

Aged↗
PubMed1997

The Post-Stroke Depression Rating Scale: a test specifically devised to investigate affective disorders of stroke patients.

Owing to the lack of instruments specifically constructed to study emotional and affective disorders of stroke patients, the nature of post-stroke depression (PSD) remains controversial. With this in mind, the authors constructed a new scale, the Post-Stroke Depression Scale (PSDS) which takes into account a series of symptoms and problems commonly observed in depressed stroke patients. The PSDS and the Hamilton Depression Rating Scale (HDS) were administered to a group of 124 patients, who had been classified, on the basis of DSM III-R diagnostic criteria, in the following categories: No depression (n = 32); Minor PSD (n = 47); Major PSD (n = 45). Scores obtained by these stroke patients on the PSDS and on the HDS were compared to those obtained on the same scales by 17 psychiatric patients also classified as major depression on the basis of DSM III-R diagnostic criteria. An analysis of the symptomatological profiles clearly showed that: (1) a continuum exists between the so-called "major" and "minor" forms of PSD; (2) in both groups of depressed stroke patients the depressive symptomatology seems due to the psychological reaction to the devastating consequences of stroke, since the motivated aspects of depression prevailed in depressed stroke patients, whereas the (biologically determined) unmotivated aspects prevailed in patients with a functional form of major depression; and (3) in stroke patients a DSM III-based diagnosis of major PSD could be in part inflated by symptoms (such as apathy and vegetative disorders) that are typical of major depression in a patient free from brain damage, but that could be due to the brain lesion per se in a stroke patient.

Adult↗
PubMed1997

Relation of lesion location to verbal and nonverbal mood measures in stroke patients.

BACKGROUND AND PURPOSE: The aim of the present study was to evaluate the relation between poststroke depression and lesion location, avoiding previous methodological shortcomings. In particular, we intended to determine whether patients with left frontal lesions showed the highest depression scores. METHODS: Patients in the study, categorized on the basis of lesion location, included 149 stroke patients with lesions located in the anterior, central, or posterior regions of the right or left hemisphere. Verbal and nonverbal mood measures as well as the Hamilton Depression Scale Overall Score were the dependent measures of our investigation. Furthermore, the number of patients who could not be assessed or could be evaluated only with the nonverbal mood measure due to the presence of severe language disorders was recorded. RESULTS: No significant relation was observed between depressed mood and lesion location. Approximately one quarter of the left brain-damaged patients were partially or totally excluded from the study because of severe language disorders. CONCLUSIONS: Our data appeared to show that when methodological pitfalls and selection bias are carefully controlled, left frontal lesions are not a major determinant of poststroke depression.

Adult↗
PubMed1996

The production of specific and generic associates of living and nonliving, high- and low-familiarity stimuli in Alzheimer's disease.

The goal of this paper was to address three issues relevant to the semantic-lexical deficit of Alzheimer's disease (AD) patients: (1) the nature of the deficit (contrasting the loss of information with the difficulty of intentional access hypothesis), (2) stimulus familiarity effects, (3) semantic category effects (contrasting living with nonliving categories). Sixteen patients affected by AD and 11 matched control subjects were given a naming task, a word-picture matching task and a generative associative naming task, constructed by using as stimuli the same 40 items. Stimuli were either living or nonliving items of high, medium, and low familiarity. Responses given on the generative associative naming task were classified as generic (poorly informative) or specific (more informative). As expected, AD patients were poorer than controls both in naming and in word-to-picture matching tasks. In the generative associative naming task, AD patients tended to produce fewer specific than generic associations with respect to controls. Category effects had a significant influence on performance only on the naming task, but not on the word-to-picture matching or on the generative associative naming task. Stimulus familiarity, on the other hand, strongly influenced performance both in AD patients and in controls: naming and comprehension were better for high familiarity items with respect to low familiarity items. For generative associative naming, the tendency of AD patients to produce fewer specific than generic associations was mainly significant for low familiarity items.

Aged↗
PubMed1996

Lateralization of brain mechanisms underlying automatic and controlled forms of spatial orienting of attention.

Unilateral Spatial Neglect (USN) can be considered as a defect in spatial orienting of attention toward the half space contralateral to the damaged hemisphere. Since the classical work of Brain, W.R. Brain 64:224-272 (1941), several authors have emphasized that this defect is definitely more frequent and severe in patients with right brain damage, but the reason for this hemispheric asymmetry has remained controversial. Several investigations conducted with different experimental paradigms in different laboratories have shown that only automatic orienting of attention toward stimuli arising in the half space contralateral to the damaged hemisphere is disrupted in USN, whereas controlled, volitional orienting can be more or less completely spared. The hypothesis that at the level of the right hemisphere, spatial orienting of attention may be mainly prompted by automatic mechanisms may, therefore, be advanced. By contrast, the left hemisphere might play a leading role in mechanisms underlying volitional orienting of attention. According to this model, recovery from USN could be due to substitution of the lost automatic orienting mechanisms with the spread volitional orienting mechanisms subserved by the intact left hemisphere.

Attention↗
PubMed1996

The Mental Deterioration Battery: normative data, diagnostic reliability and qualitative analyses of cognitive impairment. The Group for the Standardization of the Mental Deterioration Battery.

This study aimed at investigating the clinical usefulness of the Mental Deterioration Battery (MDB) in the neuropsychological diagnosis and characterization of the dementia syndrome. In this paper, we report: (a) normative data for various test scores derived from the analysis of performance of 340 normal subjects living in urban areas; (b) an evaluation of the reliability of the single tests and of the battery as a whole in differentiating normal subjects from patients affected by cognitive deterioration derived from the analysis of performance of 130 normal subjects living in rural areas and 134 patients affected by probable Alzheimer's dementia; (c) a cluster analysis of performances of the 340 normal subjects in the standardization group to evaluate possible criteria of homogeneity according to which the various MDB scores tend to aggregate; (d) an analysis of performance profiles of 183 patients with right monohemispheric focal lesions, 159 patients with left unilateral lesions with aphasia and 131 left-lesioned nonaphasic patients to evaluate the specificity of the single tests of the battery in documenting a selective impairment of one of the two cerebral hemispheres. Results confirm the reliability of the MBD in discriminating between normal and demented patients and provide indications for use of the battery in differentiating qualitative patterns of cognitive impairment.

Adult↗
PubMed1995

Neuropsychological tests and [99mTc]-HM PAO SPECT in the diagnosis of Alzheimer's dementia.

Twenty-three patients with Alzheimer's dementia (AD) in relatively early stages and 40 patients with other cognitive disorders of vascular or degenerative aetiology underwent neuropsychological examination and [99mTc]-HM PAO single photon emission computed tomography (SPECT). In contrast to the commonly accepted notion of a posterior temporoparietal reduction of tracer uptake as the typical SPECT pattern of AD, the most consistent feature found in the SPECT images of our AD patients was a hippocampal uptake deficit, associated with a variable degree of temporal, parietal and frontal deficit (extending from the posterior to the anterior regions), according to the severity of the disease. These results support the theory of AD as a "hippocampal dementia", at least in the early stages. Neuropsychological tests were found to be somewhat more specific and more accurate than SPECT in distinguishing AD from non-AD cases.

Aged↗
PubMed1995

Some preliminary findings concerning a new scale for the assessment of depression and related symptoms in stroke patients.

The authors describe a new scale, the Post-Stroke Depression Rating Scale (PSDRS), specifically constructed to investigate the emotional, affective and vegetative disorders of stroke patients. They also report some preliminary data concerning the validity and reliability of the new scale and of its sections and the first results obtained administering the PSDRS to 68 stroke patients and 10 subjects affected by a "functional" form of major depression. The comparison between the results obtained on the PSDRS by patients classified (on the basis of DSM III diagnostic criteria) as having major depression of either vascular or functional origin seems to show an incomplete overlap between these two forms of depression. In patients classified as having major post-stroke depression, part of the symptomatology seems to be due either to the direct effect of the brain lesion or to the psychological reaction of the patient to the disabilities and handicaps provoked by the lesion.

Cerebrovascular Disorders↗
PubMed1995

Pseudotumor cerebri as presenting syndrome of Addisonian crisis.

In a patient who developed clinical signs of intracranial hypertension, bilateral papilledema and diplopia, in association with mild hypotension, hyponatremia and hyperkalemia, the hypothesis of Addison's disease was raised and confirmed. Substitutional therapy led to complete recovery. The present paper represents the first report of pseudotumor cerebri as the only clinical sign of an Addisonian crisis.

Addison Disease↗
PubMed1994

Evidence for a possible neuroanatomical basis for lexical processing of nouns and verbs.

Neuropsychological studies have revealed that brain-damaged patients may show impairments of specific word categories. This study reports the performance of three patients with impairments of the categories noun and verb. The first and second patients, with left frontal lobe atrophy, were impaired in naming and comprehension of verbs. The third patient, with striking atrophy of the left temporal lobe, was disproportionately impaired in naming and comprehension of nouns. These findings suggest that anatomically distinct neural systems in the temporal and frontal lobes of the dominant hemisphere might play a critical role in lexical processing of nouns and verbs, respectively.

Aged↗
PubMed1994

Some aspects of memory disorders clearly distinguish dementia of the Alzheimer's type from depressive pseudo-dementia.

Two groups of patients affected by mild dementia of the Alzheimer's type (n = 42) or by depressive pseudo-dementia (n = 26) were given a modified version of the Rey's Auditory Verbal Learning Test. The two groups were roughly matched for overall level of cognitive impairment. The main purpose of the research was to determine if some aspects of their memory disorders distinguished the two diagnostic groups. Comparison between results obtained on recall and on recognition measures was of little diagnostic usefulness in distinguishing dementia of the Alzheimer's type (DAT) from depressive pseudo-dementia (DPD). A marked prevalence of the recency over the primary effect in immediate recall, a high rate of forgetting, and the presence of many intrusion errors on delayed recall were observed more frequently in DAT than in DPD patients. None of these indices, however, was sensitive and specific enough to allow a confident diagnostic discrimination at the individual case level. The memory measure which best distinguished DAT from DPD patients was the presence of several false positive errors on delayed recognition because DAT patients adopted a very liberal response bias, endorsing many false recognition errors, whereas DPD patients adopted a conservative criterion and tended to miss real stimuli, rather than making false recognition errors.

Aged↗
PubMed1994

Agreement in the clinical diagnosis of dementia: evaluation of a case series with mild cognitive impairment.

Interobserver agreement in the clinical diagnosis of dementia among four neurologists was evaluated. The physicians, masked to the original diagnoses, independently reviewed the clinical records of 50 outpatients consulting either the 1st University Neurology Department of Milan or the Neuropsychology Unit of the Medical Center of Veruno (Novara) for suspected cognitive impairment, during a 6-month period. The records contained patients' medical and neurological history, results of neuropsychological testing, laboratory tests, cerebral computed tomography and other investigations. For each patient, the raters had to provide both a diagnosis concerning the presence or absence of dementia and to assign an analytical diagnosis to all the dementia cases. The kappa statistic was used as a measure of interrater reliability. The level of agreement on the primary diagnosis of dementia was moderate (kappa = 0.49); with respect to the nosological diagnoses, the kappa values ranged from 0.16 for depression to 0.80 for multi-infarct dementia.

Aged↗
PubMed1994

The relationship between visuospatial and representational neglect.

Using a quantitative measure, we analyzed the relationship between visuospatial and representational neglect in right- and left-brain-damaged patients and found signs of representational neglect only in right-brain-damaged patients. Although representational neglect was always associated with visuospatial neglect, suggesting that the two forms share a common underlying mechanism, the most frequent finding in right-brain--damaged patients was that of visuospatial neglect in isolation. A strong influence of the phenomenon of attentional attraction toward space ipsilateral to the lesion in visuospatial, as opposed to imaginal, tasks can account for this finding.

Attention↗
PubMed1994

Disorders of verbal and pictorial memory in right and left brain-damaged patients.

It is still controversial whether verbal and pictorial stimuli are independently processed and stored in memory, as assumed by the dual code hypothesis, or a single code is used both for verbal and for pictorial stimuli, as assumed by the verbal loop hypothesis and by the propositional code hypothesis. According to the first hypothesis, verbal and pictorial memory are independently disrupted by brain damage, whereas according to the second hypothesis a co-occurrence of verbal and pictorial memory disorders are usually observed. To test these contrasting predictions, we constructed a verbal and a pictorial memory task very similar with respect to testing procedures and to material to be memorized and we administered them to 33 left and 27 right brain-damaged patients and to 21 normal controls. The following results were obtained: 1) Disorders of verbal and of pictorial memory were dissociated by brain injury in about one-third of our patients; 2) A consistent relationship was observed between laterality of lesion and type of selective memory impairment, since word recognition was selectively impaired by left and picture recognition by right brain injury; 3) However, only on the test of verbal memory was a significant difference between right and left brain-damaged patients obtained, whereas on the test of pictorial memory only a nonsignificant trend in the opposite direction was observed. These data are in favor of the dual code hypothesis and suggest that the links between left hemisphere and verbal code may be stronger than the relationship between right hemisphere and pictorial code.

Adult↗
PubMed1993

The riddle of the right hemisphere's contribution to the recovery of language.

Although it is generally acknowledged that the right hemisphere plays some role in the recovery of language in aphasic patients, the exact nature of this role is still controversial. According to the model of right hemisphere language proposed by Zaidel, the right hemisphere should selectively contribute to the recovery of language comprehension (and in particular of lexical comprehension) but not to the recovery of language production. According to the model of right hemisphere language proposed by Gazzaniga, on the contrary, no language function is selectively supported by the right hemisphere, but the contribution of this hemisphere to the recovery of language varies widely from one individual to another. The aim of this paper is to try and clarify this problem, starting from the basic clinical observations which have given a preliminary shape to the whole issue, and passing then to a survey of results obtained following more recent and specific lines of research. The following conclusions are reached: (1) although the right hemisphere plays (at least in some patients) a definite role in the recovery from aphasia, a greater role is usually played by the undamaged areas of the left hemisphere; (2) the right hemisphere's contribution to the recovery of language seems to concern more the receptive than the expressive components of speech; and (3) the extent of the right hemisphere's contribution varies widely from one individual to another, probably due to individual differences in the hemispheric representation of language.

Adult↗
PubMed1992

Early rightwards orienting of attention on simple reaction time performance in patients with left-sided neglect.

A specific disruption in the ability to automatically disengage attention from its previous focus has been hypothesized to account for the extinction phenomenon often observed in the unilateral spatial neglect syndrome. Recent literature, however, also brings out the role played in neglect by an imbalance in the attentional orienting systems, resulting in an early shift of attention towards the side of space ipsilateral to the brain lesion. In the present study we hypothesized that this attentional bias in orienting of attention might be demonstrated in a paradigm of simple reaction time to lateralized visual stimuli by contrasting the presence vs the absence on the computer screen of the square boxes used to facilitate position expectancy. A main prediction was made that patients with neglect would show a significant increase in reaction time to contralateral visual stimuli in the presence of bilateral reference boxes as compared to conditions in which no boxes were displayed. The right-sided box was in fact expected to exert an early attraction on the patient's attention, thus modifying the pattern of reaction times to the proper targets. This prediction was confirmed in right brain-damaged patients with moderate to severe neglect.

Adult↗
PubMed1992

Can residual lexical knowledge concern word form rather than word meaning?

We described a patient with a dramatic deficit of both word comprehension and naming but with good preservation of visual pictorial semantics. On word-picture matching, his performances were slightly better than expected based on the observed lexical semantic disorder; in addition, the patient, who maintained good preservation of his underlying phonology, showed a tendency to point to the picture phonologically related to the target. In order to interpret these data, we advanced the hypothesis that the patient, in spite of his virtually complete inability to name, would be able, in a word-picture matching task, to "covertly" (i.e., preverbally) retrieve the name from the picture and to use this name to attempt a match with the phonological form of the stimulus word. This mechanism, that we called "phonological" comprehension, would allow the identification of the correct target and would explain the choice of the phonologically related foil that was sometimes selected.

Aged↗