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.

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.

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.

Progress and controversies in neuropsychology of memory

In the first part of this paper we discuss some of the most important areas of progress and of controversy in the field of memory functions and of memory impairment. Three main issues are taken separately into account: (1) the fractionation of memory into a number of sub-systems and the relationships existing among these subsystems; (2) the main theories of amnesia and the mechanisms underlying memory disorders; (3) the main anatomoclinical forms of amnesia and the brain structures subserving various components of the amnesic syndrome. In the second part we shift from the basic research to the clinically oriented investigations, reporting the results of two studies that we have recently conducted on some aspects of memory disorders in dementia. In the first study we have shown that severity and qualitative aspects of amnesia can be used to distinguish the two most frequent clinical forms of dementia, namely the dementia of the Alzheimer's type (DAT) from the vascular forms of dementia. In the second study we have demonstrated that a fine grained analysis of memory impairment can help improving the most difficult differential diagnosis in this field, namely the distinction between DAT and depressive pseudo-dementia.

Neuropsychological markers of dementia on visual-spatial tasks: a comparison between Alzheimer's type and vascular forms of dementia

The incidence of the "closing-in" phenomenon and of the tendency to give "primitive answers" on the Raven's Colored Matrices was studied in 50 normal subjects and in two groups of Alzheimer's type (n = 41) and of vascular (n = 35) dementia patients, carefully matched as for the overall severity of dementia and the degree of visual-spatial impairment. The aims of this research were to determine if these patterns of behavior can be considered as neuropsychological markers of dementia and if their incidence is similar in the two dementia groups. Results show that both the closing-in phenomenon and the tendency to give globalistic and odd responses on the Raven's Colored Matrices are good markers of dementia and that, in particular, they point to a degenerative, rather than to a vascular form of dementia. From the clinical point of view, these data suggest that a qualitative analysis of the patient's behavior can increase the diagnostic efficacy of neuropsychological tests and that neuropsychological markers of dementia point more to Alzheimer's disease (considered as the most prototypic form of dementia) than to a vascular form of dementia even when the two groups of patients are well balanced in terms of visual-spatial impairment and the overall severity of dementia.

Early orientation of attention toward the half space ipsilateral to the lesion in patients with unilateral brain damage

Posner has suggested that unilateral spatial neglect could be due to a difficulty in disengaging attention from its current focus to orient it toward the neglected half space. Clinical and experimental data suggest, however, that this disengaging difficulty could be only one aspect of a more complex disturbance also characterized by an early automatic orienting of attention toward the half space ipsilateral to the lesion. To test this hypothesis, two different investigations in unselected groups of patients with right and left brain-damage were carried out. The first investigation, to evaluate forms of lateral orienting of attention severe enough to provoke an overt gaze deviation, consisted of the systematic assessment of the phenomenon of "magnetic gaze attraction". The second investigation, to detect milder forms of automatic orienting of attention, analysed the temporal sequence followed in identifying the pictures represented in an "Overlapping Figures task", to see if patients tended to identify first figures lying in the half space ipsilateral to the lesion. In both investigations results consistently showed: a) that patients with right brain damage tend to orient attention automatically toward the ipsilateral half space more than patients with left brain damage; b) that this tendency is tightly linked to the presence of behavioural manifestations of hemi-neglect. These results are therefore consistent with the hypothesis that hemi-neglect is a multi-component syndrome with an early orienting of attention toward the half space ipsilateral to the lesion as the first of these components.

Dissociation between knowledge of living and nonliving things in dementia of the Alzheimer type

Patients who survive herpes simplex encephalitis (HSE) sometimes present a category-specific disorder for living things. Since HSE specifically involves the temporolimbic structures of both hemispheres, these structures could play a critical role in processing and storing information about living things. If this were the case, a category-specific disorder for the same items should also be observed in the early stages of dementia of the Alzheimer type (DAT) as the temporolimbic structures are often severely affected in this condition. To test this hypothesis, we administered to 15 DAT patients and to 10 normal controls a confrontation-naming task and a verbal associates recognition task, with both living and nonliving items as stimuli. The hypothesis was confirmed, since DAT patients performed worse with living than with nonliving items, and scored worse than normal controls on the living but not the nonliving items.

Double dissociation between temporal and spatial pattern processing in patients with frontal and parietal damage

One hundred and twenty nine patients affected by a cerebral lesion confined to a single lobe, underwent a battery of tests including the "Temporal Rule Induction" (TRI) and the Raven's "Coloured Progressive Matrices" (CPM). Frontal patients scored lower than any other group on TRI and parietal patients on CPM. This contrasting pattern of performance provides strong empirical support to the hypothesis that the frontal lobe is specifically involved in tasks that require a control on temporally ordered information whereas the parietal lobe is concerned with cognitive activities that imply visuo-spatial analysis.

Contralateral and ipsilateral disorders of visual attention in patients with unilateral brain damage

To explain the prevalence of unilateral spatial neglect in patients with right brain damage, Heilman et al have suggested that the attentional neurons of the right parietal lobe might have bilateral receptive fields, whereas the homologous cells of the left hemisphere would have strictly contralateral receptive fields. One implication of this theory is that patients with right brain damage should show a prevalence of disorders of visual attention not only in the half space contralateral to the damaged hemisphere, but also in the ipsilateral one. To check this theory, 50 control subjects, 102 right and 125 left brain-damaged patients were given a drawing completion task in which patients were requested to complete the missing parts of a star, a cube and a house. Omissions of lines lying on the sides of the models contralateral and ipsilateral to the damaged hemisphere were taken separately into account. Results did not confirm the hypothesis, since right brain-damaged patients failed to complete the contralateral sides of the models much more frequently than patients with left brain injury, but no difference was found between the two hemispheric groups when ipsilateral disorders of visual attention were taken into account. Furthermore, no correlation was found between omissions of lines lying on the sides of the models contralateral and ipsilateral to the damaged hemisphere. This finding suggests that contralateral and ipsilateral disorders of visual attention are not due to the same mechanism in right brain-damaged patients. The alternative hypothesis viewing ipsilateral disorders as resulting from a widespread lowering of general attention (and only contralateral neglect reflecting a specific disorder of visual attention) was supported by results obtained on a verbal memory test, used to evaluate the general cognitive and attention level of the patients. Patients with clear-cut ipislateral inattention obtained very low scores on this test, whereas patients with severe contralateral neglect, but not ipislateral inattention scored within the normal range on the verbal memory test.

Posed emotional expression in unilateral brain damaged patients

The facial expressions of six basic emotions were posed by two groups of right (N = 23) and left (N = 34) brain damaged patients and by a control group of normal subjects (N = 28). The posed expressions were examined by means of the Facial Action Coding System (FACS) which provides analytical and objective scoring, as by a subjective scale of appropriateness of expression. Results indicated no difference between controls and patients with a lesion in the right or left hemisphere. These findings are inconsistent with the hypothesis that the right hemisphere plays a specific role in the control of posed facial expression. No relationship was observed between posed emotional expressions and facial paralysis or the presence of oral apraxia.

[Current problems in the study of aphasia]

In the introductory part of the present survey the author provides a sketchy illustration of the main anatomo-clinical aspects of aphasia, focusing attention on the main patterns of language impairment and on the corresponding cortical localizations usually observed in patients with cerebro-vascular disorders of ischemic nature. In the second part of the paper, some more recent aspects of aphasiology (namely the subcortical aphasias and the so called slowly progressive aphasia) are shortly discussed. As for the first point, it is suggested that language disorders observed in patients with purely subcortical lesions may be due to a remote effect of these lesions at the level of the cortical association areas, rather than to the subcortical injury per se. As for the second point it is still not clear if the slowly progressive aphasia is a disease or a syndrome resulting from the selective affinity for the posterior association areas of the left hemisphere of degenerative disorders, such as Pick's or Alzheimer's disease.

The influence of semantic and perceptual factors on lexical comprehension in aphasic and right brain-damaged patients

We investigated whether the errors made by aphasic patients and right brain-damaged (RBD) patients on a word-picture matching test were differently related to the semantic and perceptual difficulties of the task. To this effect, the target picture was presented in one condition along with two semantically similar distractors, in another condition with two perceptually similar distractors, and in a third condition with two distractors that were both semantically and perceptually similar. There were also two control conditions in which part of targets that had been originally shown with semantic distractors were now presented with perceptual distractors and vice versa. The findings were consistent with the hypothesis that aphasics mainly fail when the task involves semantic discrimination and RBD patients when it involves perceptual discrimination. In aphasics the semantic perceptual condition produced the highest number of errors, but this was due, it was argued, to an increase of the semantic demands of the task.

Contralateral and ipsilateral tactile extinction in patients with right and left focal brain damage

Heilman has suggested that right hemisphere lesions produce neglect both in the spaces contralateral and ipsilateral to the damaged hemisphere. To test this hypothesis, we studied the incidence of contralateral and ipsilateral tactile extinctions in 44 right and 59 left brain-damaged patients, by means of a standard test of a double tactile simultaneous stimulation of symmetrical and asymmetrical parts of the two sides of the body and of ipsilateral body parts. Results did not confirm Heilman's hypothesis; while contralateral tactile extinction was more frequent and severe in right than in left brain-damaged patients, no hemispheric difference was found when the number of ipsilateral extinctions was taken into account. Furthermore, ipsilateral tactile extinction was significantly related to aspecific factors (such as age, severity of sensorimotor impairment and widespread mental deterioration), irrespective of the hemispheric side of lesion.

Can the pattern of neuropsychological improvement obtained with cholinergic drugs be used to infer a cholinergic mechanism in other nootropic drugs?

1. Enhancement of episodic memory and reduction of intrusion errors are considered as the most characteristic outcome of cholinergic drugs administration in AD patients. 2. Since the nootropic drugs Piracetam and Oxiracetam are deemed to act through a cholinergic mechanism, we checked whether AD patients treated with these drugs would show the same pattern of neuropsychological improvement. 3. Results were negative, since (a) episodic memory showed a similar degree of improvement both in patients treated with these drugs and in patients treated with placebo; (b) the number of intrusions tended to increase, rather than to decrease, after the treatment period.

Spontaneous facial expression of emotions in brain-damaged patients

Spontaneous facial expression of emotion was studied in two groups of right (N = 23) and left (N = 39) brain-damaged patients and in a control group of normal subjects (N = 28). To elicit emotions four short movies, constructed to produce positive, negative or neutral emotional responses, were used. The method used to assess the facial expression of emotions was the Facial Action Coding System. Brain-damaged patients showed less facial responses to emotional stimuli than normal controls, but no difference was observed between subjects with right and left-sided lesions either with global or disaggregated data analyses, inconsistent with the hypothesis of a specialization of the right hemisphere for facial emotional expressions. An unexpected difference was observed in response to the unpleasant movie. Both normal controls and left brain-damaged patients often averted their gaze from the screen when unpleasant material was displayed, whereas right brain-damaged patients rarely showed gaze aversion. This finding suggests that the degree of emotional involvement or manner of coping with stressful input may be reduced as a result of right brain damage.

[Disorders of autonomic responses to emotional stimuli in patients with unilateral hemispherical lesions]

The authors have studied in 31 patients affected by right (N = 12) or left (N = 19) hemispheric lesions and in 10 normal controls the autonomous response to emotional stimuli. Stimuli consisted of 3 short films, aiming to provoke respectively a negative emotional reaction, a positive emotional response or a non-emotional reaction. Galvanic skin response and heart rate were considered as the dependent variables of our research. Both normal controls and left brain-damaged patients were very influenced by the emotional nature of the stimuli and showed clear signs of activation of the sympathetic and para-sympathetic systems in front of emotional films. By contrast, right brain-damaged patients were not influenced by the emotional or non-emotional nature of the stimuli and showed neither a clear galvanic skin response nor a significant decrease of heart rate in front of emotional films.

Mechanisms of unilateral spatial neglect in relation to laterality of cerebral lesions

An Overlapping Figures test, considered as appropriate to study focusing of attention on small but complex stimuli falling in the central parts of visual field and a Searching for Animals test, designed to study the exploration of large parts of extrapersonal space, were administered to 38 controls, and 90 right and 82 left brain-damaged patients. The investigation was designed to test the hypothesis that the extent of space to be explored may have a different influence on unilateral spatial neglect of right and left brain-damaged patients. Both right and left brain-damaged patients showed an asymmetric exploration of space on the Searching for Animals test, making more omissions on the side contralateral to the damaged hemisphere than on the ipsilateral one. On the Overlapping Figures test, however, only right brain-damaged patients showed a clear tendency to omit figures lying on the left side of the composite pattern. This finding suggests that inability to extract visual information from one side of the stimuli during single eye fixations may be the most characteristic feature of unilateral spatial neglect resulting from right hemisphere lesions.

Interictal psychopathology in temporal lobe epilepsy. The role of laterality of the epileptic focus

The relationship between interictal psychopathology and laterality of the EEG focus in temporal lobe epilepsy was investigated by administering the Minnesota Multiphasic Personality Inventory (MMPI) to 37 epileptic patients, with an EEG focus lateralized to the right (N = 12) or left (N = 25) temporal lobe. T scores obtained on the various scales of the MMPI were used for evaluating incidence and degree of psychopathology. No relationship was observed between laterality of temporal lobe epilepsy and associated interictal psychopathology. The hypothesis that a temporo-limbic epileptic focus may interact with the characteristic organization of each cerebral hemisphere to induce different psychopathological traits is not supported by our data.

Constructive disabilities in focal brain-damaged patients. Influence of hemispheric side, locus of lesion and coexistent mental deterioration

The performance of 185 focal brain-damaged patients on two non-verbal constructive tasks ('Copying Drawings' and 'Copying Drawings with Landmarks') was evaluated with regard to three variables: laterality of cerebral lesion, intrahemispheric locus of lesion, and coexistence of mental deterioration. The aim of the study was to assess the relationships between each of these variables and both the incidence and severity of constructional apraxia. Different evaluations were carried out in order to partial-out the possible interference of unilateral spatial neglect. Results showed that, regardless of whether faults attributable to unilateral spatial neglect were penalized or not: right brain-damaged patients performed slightly worse and showed a higher percentage of pathologic performances than left brain-damaged patients; subjects with parietal--and particularly with right parietal--damage obtained the poorest mean scores and exhibited the highest incidence of apraxic performances; and coexistence of mental deterioration was the most relevant variable associated with global decay of constructive scores and incidence of constructional apraxia.

Focal brain lesions and intelligence: a study with a new version of Raven's Colored Matrices

Contrasting results have been obtained in previous investigations, which have used the standard version of Raven's Colored Progressive Matrices for studying the effects of localized brain lesion on visual-spatial intelligence. Some of these discrepancies might be due to the fact that specific factors, such as unilateral spatial neglect, could contribute to decreased performance obtained on Raven's test by patients with focal brain lesions. A new set of Colored Matrices, devised to minimize the influence of unilateral spatial neglect without changing the essential features of the original task, was therefore constructed. The test was administered to 76 normal controls, 74 right brain-damaged patients, 87 aphasics, and 61 nonaphasic left brain-damaged patients, in order to study the effect of laterality of lesions and of language impairment on Raven's scores. The results show that, if the influence of unilateral spatial neglect is minimized and Raven's scores are corrected in reference to age, educational level, and lesion size, then: no significant differences are observed between right and left brain-damaged patients; aphasics score worse than nonaphasic left brain-damaged patients; impairment is greater in patients with Wernicke's and Global aphasia (i.e., in patients with severe language comprehension disorders) than in patients classified as Broca's, Anomic, or Conduction aphasia; impairment is greater in patients with semantic-lexical discrimination errors than in patients free from semantic-lexical comprehension disorders.

Are drawing errors different in right-sided and left-sided constructional apraxics?

The drawings of 70 control subjects, 95 right and 118 left brain-damaged patients (BDP) were evaluated by two independent judges having no knowledge of the literature on constructional apraxia, who were requested to give both a quantitative and a qualitative evaluation of each drawing. Scoring made it possible to classify the BDP as affected or not affected by constructional apraxia. Qualitative errors were classified in two groups: (A) "executive" errors: increased number of right angles, structural simplification of the models and omission of details and (B) "visualspatial" errors: inattention to lateral elements or omission of one half of the figures, errors in spatial relations and diagonal orientation of the drawings. Contrary to expectations, no clear qualitative difference was observed between the drawing errors of right and left BDP. The types of errors most frequently observed in constructional apraxics were very similar, irrespective of lesion side, and consisted in difficulty in reproducing the spatial relations between the various parts of the models and in a tendency to oversimplify the most difficult designs. The only type of error which differentiated right apraxics from left apraxics was omission of lines or of whole figures on the half space contralateral to the damaged hemisphere, but this type of error could not be responsible for right-sided constructional apraxia, since judges had been instructed to base their assessment only on the parts of the models actually reproduced by the patients without scoring as errors manifestations of neglect. These results do not support the hypothesis that two different mechanisms, "executive", and "visual-spatial", underlie constructive disabilities of left and right brain-damaged patients.

Dementia in Parkinson's disease: possible specific involvement of the frontal lobes

We carried out a neuropsychological study on cognitive impairment in 57 subjects affected by idiopathic Parkinson's Disease (PD) and 32 subjects affected by Alzheimer's Disease (AD). First, we found two different subgroups of Parkinsonian patients, the first one with and the second without dementia. We clearly identified these two distinct subclinical entities regardless of mean age, age of onset, duration of treatment; on the contrary, the type of treatment seems to play a specific role in the appearance of dementia in PD, anticholinergics being assumed almost exclusively by demented Parkinsonian patients. Second, we observed two main differences for cognitive impairment between PD with dementia and AD. In fact, cognitive impairment is consistently more evident in Alzheimer patients than in Parkinsonian ones with dementia; in addition, demented Parkinsonians show a pattern of impairment similar to that exhibited by patients affected by frontal lobe lesions. This result supports neuroanatomical and neurochemical data on the involvement of the whole dopaminergic system in PD and the role played by the ventromedial tegmental area projecting to the frontal cortex in causing cognitive dysfunction in this disease.

Some methodological problems in the study of the relationships between emotions and cerebral dominance

The findings of studies involving brain-damaged patients and those with normal subjects are considered separately in a review of the most important investigations that have led to the hypothesis that the right hemisphere is dominant for various aspects of emotional behavior. This paper examines some of the methodological problems encountered in studies of laterality of emotions, again looking at investigations of brain-damaged patients and of normal subjects. Future directions for research into emotional lateralization are suggested.

Drawing objects from memory in aphasia

The ability of aphasic patients to draw from memory objects with a characteristic shape has been investigated. Their capacity to reproduce the form of real objects was studied by showing them for a short time line drawings of simple objects. When the patient had analysed and recognized the figure, the model was hidden from view and the subject was asked to draw the same object from memory. This Drawing from Memory task was administered to 54 aphasics, 67 patients with right hemisphere lesions, 44 nonaphasic left brain-damaged patients and 23 normal controls. The influence of visuoconstructive disabilities was controlled by administering to the same patients a standard test for constructional apraxia (copying 10 geometrical figures). The severity and clinical form of the aphasia and the presence of semantic-lexical impairment at the receptive level were also examined in the aphasic patients. The following results were obtained. (1) Aphasic patients scored significantly less well than the control groups on the Drawing from Memory task and the intergroup differences became greater when the scores from the test for constructional apraxia were included by an analysis of covariance. (2) No significant correlation was detected between the severity and clinical form of the aphasia and the scores obtained on the Drawing from Memory task. (3) There was a significant correlation between impaired drawing from memory and disruption at the semantic-lexical level of language integration.

The production of morphological and lexical opposites in aphasia

Four unselected groups of Broca's, Wernicke's, conduction, amnesic aphasic patients and a group of normal controls were asked to produce the best opposite of 60 adjectives. For half of the stimuli the expected opposite was morphologically related to the stimulus word (e.g. "formal"/"informal"), for the other half it could be obtained only by selecting a new base-form within the lexicon (e.g. "good"/"bad"). Following some neurolinguistic observations by Hécaen et al., it was predicted that amnesic patients should produce mainly morphological opposites, whereas conduction aphasics should produce mainly lexical antonyms. Results confirmed the predictions, since amnesic aphasics showed a prevalent impairment in the selection lexical opposites, whereas conduction aphasics showed a selective impairment in the production of morphological antonyms.

Acute administration of individual optimal dose of physostigmine fails to improve mnesic performances in Alzheimers Presenile Dementia

Eight patients affected by Alzheimer's Presenile Dementia (AD) received acute administration of physostigmine individual optimal dose per os (n = 4) or subcutaneously (n = 4). The individual physostigmine dose was assessed by means of serum cholinesterase activity monitoring. The possible beneficial effects after treatment were evaluated by using two memory tests: Reys' 15 words and Digit Span from Wechsler memory scale. Although a slight behavioral activation was noted in all patients after treatment, the comparison between mean scores obtained by AD patients in mnesic tests before and after the acute physostigmine administration, with either therapeutic modality, failed to reach the level of statistical significance. Some implications of these disappointing results are briefly discussed.

Oral administration of chronic physostigmine does not improve cognitive or mnesic performances in Alzheimer's presenile dementia

Physostigmine was administered orally 1 mg q.i.d. for one month to 8 patients with a clinical diagnosis of Alzheimer's presenile dementia. The possible beneficial effects of the drug were evaluated by means of a neuropsychological battery administered to all patients before and after treatment. The performances obtained by demented patients on retest did not show any difference in comparison with performances obtained on the first neuropsychologic assessment. Some implications of these negative results are briefly discussed.

Neurophysiological study of normal pressure hydrocephalus

A neuropsychological Mental Deterioration Battery (MDB) was used to identify deterioration profiles of 43 patients afflicted with normal pressure hydrocephalus (NPH) (n = 18) or other forms of dementia (n = 25). The NPH patients submitted to a shunt-intervention (n = 10) were also evaluated after surgery. A comparison of profiles, obtained from the experimental and control groups, shows that NPH patients seem to be more impaired in tests designed to detect frontal lobe involvement. Some implications of the relatively greater impairment of frontal functions in NPH dementia are discussed.

Influence of age, sex, literacy and pathologic lesion on incidence, severity and type of aphasia

The influence of sex, age, educational level and pathologic lesion on incidence, severity and clinical form of aphasia was investigated in 390 right-handed, left brain-damaged patients. Sex and educational level were not related to any parameter. Etiology of lesion and age were related to both incidence and type of aphasia. Incidence of aphasia increased with age and was higher in patients with cerebrovascular accidents than in subjects with other types of brain lesions. Non-fluent forms of aphasia were more frequent in young patients suffering from acute cerebrovascular accidents, whereas anomia prevailed in neoplastic subjects and Wernicke's aphasia increased regularly in frequency with age. Some tentative explanations of these findings are discussed.

The relationship between type of naming error and semantic-lexical discrimination in aphasic patients

When submitted to confrontation naming tasks, aphasic patients show different types of naming errors: phonetic, phonemic and verbal-semantic paraphasias, neologisms and anomia, but it is generally difficult to decide whether these errors are mainly due to a breakdown of the semantic systems or to post-lexical phonological disorders. In order to clarify this issue, 118 aphasic patients were given 3 tests of confrontation naming and 3 tests of semantic-lexical discrimination. Naming errors on confrontation were used to classify aphasic patients in various subgroups (according to the prevalence of a given type of naming error), whereas performances obtained on tests of semantic-lexical discrimination were taken as an index of disorganization of the semantic systems. The performances on semantic discrimination tests of patients showing a prevalence of phonetic, phonemic and verbal-semantic paraphasias, neologisms and anomia on confrontation naming tasks were compared. A very small number of semantic discrimination errors was obtained by patients showing a prevalence of phonetic and phonemic transformations on confrontation, whereas a much larger number of semantic discrimination errors was obtained by patients showing a prevalence of verbal-semantic paraphasias, neologisms and anomia.

Choline acetyltransferase (ChAT) activity differs in right and left human temporal lobes

Choline acetyltransferase (ChAT) activity was studied in different areas and in sequential sections of the cortical layers in the first temporal gyrus of left and right hemispheres of four human brains. The ChAT activity values obtained in all the samples from left hemisphere were significantly higher than in the right hemisphere. Furthermore, the study of ChAT activity in the cortical layers in Brodmann area 22 shows a greater left prevalence of enzymatic activity in cortical layers II and IV. The biochemical data seem to suggest a possible morphologic and/or functional difference between the two hemispheres.

Neuropsychological correlates of localized cerebral lesions in non-aphasic brain-damaged patients

A neuropsychological test battery made up of verbal, visual-spatial, and intelligence tests was administered to 82 right and 67 on-aphasic left brain-damaged patients with localized cerebral lesions, in order to draw impairment profiles of the various subgroups. Separate analyses were undertaken on patients with unilobar and multilobar lesions. As for hemisphere effects, LH patients performed worse than RH subjects on verbal tests, while the reverse was true for visual-spatial tasks. As for lobe effects, patients with frontal lobe damage fared worse than other subgroups on word fluency, independent of the side of the lesion. RH patients with multilobar posterior lesions were significantly more impaired than other RH subgroups on the test of Copying Drawings with Landmarks, probably owing to the detrimental effect of unilateral spatial neglect on tasks requiring an accurate visual-spatial analysis.

Contiguity versus similarity paraphasic substitutions in Broca's and in Wernicke's aphasia

The present research was carried out to determine whether Jakobson's claim that Broca's aphasic patients emit chiefly semantic paraphasias of the similarity type, whereas Wernicke's aphasic patients produce mainly paraphasic substitutions of the contiguity type, can be supported by data gathered for clinical purposes under controlled conditions. Semantic paraphasias produced by 96 aphasic patients on a standard test of visual naming were taken into account. Three independent judges, blind to aphasia type, classified all responses retained as semantic substitutions into one of the following four categories: those having 1) a strong similarity, 2) a strong contiguity, 3) a mild similarity, and 4) a mild contiguity relation to the correct word. No relationship was found between type of semantic paraphasias and clinical form of aphasia. Furthermore, irrespective of the clinical form of aphasia, aphasics tend to give more similarity substitutions than contiguity substitutions.

Biochemical differences between the left and right hemispheres. Preliminary observations on choline acetyl transferase (CAT) activity

Choline acetyltransferase (CHAT) activity was studied in different areas in the first temporal gyrus of left and right hemispheres of human brains. The CHAT activity values obtained in all the samples from left hemisphere wee significantly higher than in the right hemisphere. The biochemical data seems to suggest a possible morphological and/or functional differences between the two hemispheres.

Validity of some neuropsychological tests in the assessment of mental deterioration

Eighty-three control subjects and 200 patients suspected of diffuse cerebral damage were submitted to the Mental Deterioration Battery. Three independent judges evaluated each patient on the basis of all available data. Only 103 patients, unanimously classed as demented by the three judges were retained. On the basis of controls' performances, the scores obtained by each demented patient in the various tests were corrected for age and educational level. Both single tests and the Battery as a whole discriminated normal controls from demented patients at a very satisfactory level.

[Visuo-constructive disorders in right and left brain-damaged patients (author's transl)]

There seems to be some lack of agreement between clinical and experimental findings pertaining to the neurodynamic mechanisms of visuo-constructive disabilities in right and left brain-damaged patients. Clinical studies have revealed qualitative differences between drawing disabilities of right and left hemispheric origin, while experimental data suggest that the same mechanism underlies both types of constructional disorder. In order to reconcile these conflicting findings, the existence of "nuclear" impairment and more "peripheral" disturbances in constructional apraxia is suggested. Nuclear impairment seems to consist of a visuo-perceptive disorder independent of the hemispheric locus of lesion; peripheral disturbance could be different in right and left brain-damaged patients, motor and symbolic disorders being typical of left-sided lesions while unilateral spatial neglect would be characteristic of right hemispheric injuries.

The relationships between conceptual and semantic-lexical disorders in aphasia

A nonverbal test of conceptual thinking was administered to 55 normal controls and to 203 patients with monohemispheric brain lesions (74 aphasics and 129 nonaphasic brain-damaged patients), in order to study the relationships between conceptual impairment of aphasic patients and breakdown of the semantic-lexical level of integration of language. A very high number of aphasic patients (54 out of 74) and a limited number of nonaphasic brain-damaged subjects (31 out of 129) obtained a pathological score on the test of conceptual thinking, but only some components of the aphasic symptomatology seemed closely linked to the conceptual disorder. In fact a non-significant relationship was found between conceptual impairment and: ("fluent" or "non-fluent") clinical type of aphasia; severity of aphasic disturbance. On the contrary, a strong relationship was found between conceptual disorder and impairment of the semantic-lexical level of integration of language. These findings seem to show that conceptual disturbance and semantic-lexical troubles are closely linked in aphasia.

Constructional apraxia and visuoperceptive disabilities in relation to laterality of cerebral lesions

The main purpose of the present study was to determine whether constructional apraxia is due to a visual perceptual disorder in right but not in left brain-damaged patients. In order to resolve this question, 36 normal controls and 73 brain-damaged patients with lesions restricted to the right (N = 30) or to the left (N = 43) cerebral hemisphere were given a graphomotor and a multiple choice version of the Benton Visual Retention Test. The graphomotor version of the V.R.T. was used as a test of constructional praxis, whereas the multiple choice version of the V.R.T. was used as a test of visual form discrimination. No difference was found between right and left brain-damaged patients with respect to incidence and severity of visuo-constructive and of visuo-perceptive disabilities. Contrary to the hypothesis, the relationship between perceptual and praxic tasks was higher in left than in right brain-damaged patients. The high level of correlation found between graphomotor and perceptual scores within the left hemispheric group was due chiefly to the poor performances obtained on both tasks by aphasic patients. These findings are interpreted as suggesting that the basis for visuoconstructive disturbances is a perceptual disorder, independently of the hemispheric side of lesion. The contrasting results of our intercorrelational study and of analogous studies reported in neuropsychological literature are interpreted as being due to sampling differences, in the absence of clearcut qualitative or quantitative differences between visuo-constructive disabilities of right and left brain-damaged patients.

Constructional Apraxia in Left Brain-Damaged Patients: A Planning Disorder?

The aim of the present study was to verify the hypothesis advanced by Hécaen and Assal (1970), that the presence of landmarks can improve the copying performance of left brain-damaged patients, while leaving unchanged that of right brain-damaged patients. Sixty-two control subjects and 196 brain-damaged patients with lesions restricted to the right (N = 84) or to the left (N = 112) cerebral hemisphere were given two tests of copying drawings. In the first task the patients were asked to directly copy a drawing; to perform the second test they were given guiding landmarks. On both tests no difference was found between the performance of the two hemispheric groups. Right-sided patients used a lower number of guiding landmarks, but this occurred only on the half of the drawings contralateral to the side of the lesion and was apparently due to unilateral spatial neglect.

Gangliosides in the treatment of mental deterioration. A double-blind comparison with placebo

Thirty patients showing signs of mental deterioration were submitted to a neuropsychological battery before and after treatment with gangliosides. Their performances were compared, in a double-blind study, with those obtained on the same tests by 30 patients affected by similar degrees of dementia and treated with placebo. The improvement shown on Raven's Coloured Progressive Matrices and on Immediate Visual Memory by the active group was significantly higher than that shown by the placebo group. Furthermore, an evaluation of the overall effect of gangliosides therapy showed a highly significant difference between the active and placebo group, still in favour of the subjects treated with gangliosides. It is concluded that gangliosides may exert a positive effect in the treatment of demential syndromes.