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PubMed1999

Spatial deficits in ideomotor limb apraxia. A kinematic analysis of aiming movements.

Ideomotor limb apraxia is a classic neurological disorder manifesting as a breakdown in co-ordinated limb control with spatiotemporal deficits. We employed kinematic analyses of simple aiming movements in left hemisphere-damaged patients with and without limb apraxia and a normal control group to examine preprogramming and response implementation deficits in apraxia. Damage to the frontal and parietal lobes was more common in apraxics, but neither frontal nor parietal damage was associated with different arm movement deficits. Limb apraxia was associated with intact preprogramming but impaired response implementation. The response implementation deficits were characterized by spatial but not temporal deficits, consistent with decoupling of spatial and temporal features of movement in limb apraxia. While the apraxics' accuracy was normal when visual feedback was available, it was impaired when visual feedback of either target location or hand position was unavailable. This finding suggests that ideomotor limb apraxia is associated with disruption of the neural representations for the extrapersonal (spatial location) and intrapersonal (hand position) features of movement. The non-apraxic group's normal kinematic performance demonstrates that the deficits demonstrated in the apraxic group are not simply a reflection of left hemisphere damage per se.

Analysis of Variance↗
PubMed2000

Limb apraxias: higher-order disorders of sensorimotor integration.

Limb apraxia comprises a wide spectrum of higher-order motor disorders that result from acquired brain disease affecting the performance of skilled, learned movements. At present, limb apraxia is primarily classified by the nature of the errors made by the patient and the pathways through which these errors are elicited, based on a two-system model for the organization of action: a conceptual system and a production system. Dysfunction of the former would cause ideational (or conceptual) apraxia, whereas impairment of the latter would induce ideomotor and limb-kinetic apraxia. Currently, it is possible to approach several types of limb apraxia within the framework of our knowledge of the modular organization of the brain. Multiple parallel parietofrontal circuits, devoted to specific sensorimotor transformations, have been described in monkeys: visual and somatosensory transformations for reaching; transformation of information about the location of body parts necessary for the control of movements; somatosensory transformation for posture; visual transformation for grasping; and internal representation of actions. Evidence from anatomical and functional brain imaging studies suggests that the organization of the cortical motor system in humans is based on the same principles. Imitation of postures and movements also seems to be subserved by dedicated neural systems, according to the content of the gesture (meaningful versus meaningless) to be imitated. Damage to these systems would produce different types of ideomotor and limb-kinetic praxic deficits depending on the context in which the movement is performed and the cognitive demands of the action. On the other hand, ideational (or conceptual) apraxia would reflect an inability to select and use objects due to the disruption of normal integration between systems subserving the functional knowledge of actions and those involved in object knowledge.

Apraxia, Ideomotor↗
PubMed2005

Type 1 ataxia with oculomotor apraxia with aprataxin gene mutations in two American children.

Ataxia and oculomotor apraxia are seen in ataxia-telangiectasia, type 1 ataxia with oculomotor apraxia, and type 2 ataxia with oculomotor apraxia; however, only type 1 ataxia with oculomotor apraxia is associated with aprataxin gene mutation. We report two American children, a sister and a brother, with type 1 ataxia with oculomotor apraxia and aprataxin gene mutations and briefly review type 1 ataxia with oculomotor apraxia.

Apraxias↗
PubMed1995

Ataxia-oculomotor apraxia syndrome.

Ataxia-oculomotor apraxia is a distinct entity first comprehensively described in 1988. The features include early childhood onset of ataxia and oculomotor apraxia, mimicking ataxia telangiectasia but without the extraneurologic findings of ataxia telangiectasia. We add to the clinical description of the ataxia-oculomotor apraxia syndrome by reporting eight patients, ages 2 to 15 years, from four families, suggesting autosomal recessive inheritance, with the longest follow-up over 6 years. After initial gait deterioration, all had a nonprogressive course. We have postulated that ataxia-oculomotor apraxia should be established as a separate disease from ataxia telangiectasia or its variants not only by clinical history, examination findings, and course, but primarily by the biologic markers of normal chromosome breakage and radiation sensitivity studies. We found no increased chromosome breakage in the four patients studied and intermediate sensitivity to chronic ionizing radiation of cultured skin fibroblasts on the three patients studied. Family studies revealed an intermediate radiosensitivity from two patients, their asymptomatic parents, and a sister. The lack of chromosome breakage strongly separates ataxia-oculomotor apraxia from ataxia telangiectasia. The radiation sensitivity studies are compatible with two possibilities: (1) symptomatic ataxia telangiectasia heterozygotes, but this would be highly unusual because the degree of clinical involvement in the ataxia-oculomotor apraxia patients is not mild, as would be expected if they were heterozygotes and (2) a separable disease entity, which is the interpretation we favor.

Adolescent↗
PubMed1997

Conceptual apraxia from lateralized lesions.

Models of praxis have posited two major components, production and conceptual. Conceptual praxis disorders may occur in two domains: associative knowledge (tool-action associations such as hammer pound; tool-object associations such as hammer nail) and mechanical knowledge such as knowing the advantage that tools afford. Patients with Alzheimer's disease not only have conceptual apraxia (CA) but can dissociate CA from language deficits and from praxis production deficits (ideomotor apraxia). These findings suggests that knowledge about tools (action semantics) is independent of verbal semantics as well as movement representations. To learn if conceptual praxis knowledge is stored in one hemisphere (right or left) and if associative and mechanical conceptual praxis knowledge can be dissociated, we studied 29 right-handed subjects with unilateral strokes. Ten had left-hemisphere damage with no ideomotor apraxia. Eleven had left-hemisphere damage with ideomotor apraxia. There were eight right-hemisphere-damaged controls and 10 normal controls. These subjects were given tests for conceptual apraxia. There was a significant difference between groups, the left-hemisphere group with ideomotor apraxia being most impaired on both the associative and mechanical CA tests. There was a trend for associative and mechanical knowledge to be dissociated. Although conceptual praxis representations are stored in the left hemisphere, analysis of lesion sites did not reveal where in the left hemisphere they may be stored.

Aged↗
PubMed1995

Sensorimotor learning in ideomotor apraxia.

Sensorimotor learning ability in patients with ideomotor apraxia was investigated, using as subjects, eight patients with ideomotor apraxia, 8 with aphasia without ideomotor apraxia, and 8 normal controls. The aphasia, apraxia, and normal control groups were matched for age, sex, and education. The aphasia and apraxia groups were chosen to control for lesion size and scores on Kimura's recurring figure test, the Token test, and intelligence. The mirror-aiming test was performed and the learning effect in terms of decreases in total time, the number of errors, and the times for errors were examined. There was no statistically significant difference between the learning effect of the apraxic group and that of the aphasic group for total time, the number of errors, and the times for errors; however, there were group differences on each trial for number of errors and the times for errors. These results suggest that patients with ideomotor apraxia have some difficulties in motor performance rather than disturbance of learning.

Aphasia↗
PubMed1997

The mechanisms for adult-onset apraxia and developmental dyspraxia: an examination and comparison of error patterns.

OBJECTIVES: The purpose of this study was to determine whether persons with developmental dyspraxia and apraxia make similar errors during the performance of four types of tasks. METHOD: Three groups of subjects with dyspraxia or apraxia (i.e., children with learning disabilities and dyspraxia, young adults with learning disabilities and dyspraxia, older adults with left-hemisphere brain damage with apraxia) and three groups of age-matched control subjects (i.e., children, young adults, older adults) were observed performing transitive, intransitive, verbal command, and imitation tasks. Performance was scored on the basis of the types of errors made. Errors were classified as conceptual (nonrelated, unrecognizable, sequencing) or production (omission, perseveration, related, internal configuration, external configuration, incorrect movement, body part as object). RESULTS: No significant difference was found between conceptual and production error patterns for any group. In addition, there was no significant difference between the dyspraxia and apraxia groups or among the control groups on the specific types of production errors made. However, the dyspraxia and apraxia groups differed in the type of conceptual error made on the intransitive task. The body-part-as-object error was the most frequently made error on the transitive, verbal command, and imitation tasks, whereas the movement error was the most frequently made error on the intransitive task. CONCLUSION: Subjects with dyspraxia or apraxia make similar errors, suggesting that the praxis behaviors are similar.

Adult↗
PubMedDate not supplied

[Apraxia of ideas and movements and visual-constructive skills].

OBJECTIVES: To study alterations in copying behaviour in Alzheimer's disease (AD) and its relationship with other cognitive parameters. As secondary objectives, in this paper we describe the evolution of concepts, definitions and examination of ideas-movement and constructive apraxia, together with its involvement in AD and review the investigations of the Uruguayan school on the development of behaviour copying and how this is affected in patients with cerebral lesions. PATIENTS AND METHODS: We made a study of 82 consecutive patients with probable AD at stages 3 to 5 on the overall deterioration scale (GDS), registered in the Department of Neuropsychology, and a group of healthy persons, paired for age, sex and educational level. We used an extensive protocol for cognitive evaluation. We evaluated the idea-movement apraxia by means of imitation of increasingly complex gestures, and constructive apraxia using the protocol described by Mendilaharsu et al. RESULTS: At stages 4 and 5 of the GDS scale, the idea-movement apraxia was significantly correlated with digital agnosia and the anomias. Constructive apraxia was found in GDS stage 3. We found 'homogeneous cognitive deterioration' in advanced patients (GDS 5) who showed closing-in when copying figures. The closing-in correlated significantly with the presence of anomias, idea apraxia and digital agnosia. CONCLUSION: In the early stages, EA shows varied praxis profiles, but above stage 5 of the GDS scale there was a tendency to homogeneity.

Alzheimer Disease↗
PubMed1991

[Left unilateral apraxia].

A 32-year-old right-handed man suffered a traffic accident with head injury, resulting in loss of spontaneity, right hemiparesis, severe aphasia, and unilateral apraxia, which was noticed on his non-paralyzed left hand. An MRI scan conducted 11 months after onset revealed a large lesion in the left frontal lobe, a small lesion in the right frontal lobe and a striking thinning of the trunk of the corpus callosum with remarkable dilatation of the lateral ventricles. An IMP-SPECT scan, performed 1 year after onset, showed a diffuse hypoperfusion extending to the left temporo-parietal area further than the MRI verified abnormal density areas. The patient's praxic abilities were precisely evaluated 1 year after onset. The performance on the object use task was characterized by content errors. For example, when using a match with his left hand, he always treated with it like a cigarette. The right hand performance of this task was clumsy due to his right hemiparesis but successful. The performance on his left hand did not improved even when the patient was given visual examples. The term "ideational apraxia" proposed by Liepmann, which was characterized by content errors, implies a conceptual deficit. Morlaas defined ideational apraxia as a agnosia of usage. Ideational apraxia has been so far investigated mainly on patients with these difficulties in both hands. On the other hand, left unilateral apraxia has been explained by callosal disconnection. Liepmann and Maas thought that a lesion of the corpus callosum would prevent the space-time engrams in the left hemisphere from reaching the right sensorimotor area necessary to carry out the skilled act with the left hand, thereby inducing apraxia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Acquiring and maintaining self-care skills after stroke. The predictive value of apraxia.

The degree of self-care in 120 patients who had suffered unilateral cerebrovascular accident (CVA) was assessed at different stages of recovery. The level of ADL (activities of daily living) function was determined on admission and discharge. Patients with right-sided hemiplegia (r. hem.) were given a set of apraxia tests on admission to the hospital. The results of ADL evaluation showed improved ADL function between admission and discharge, but a worsening after returning home. There were some significant relationships between ADL function in hospital and apraxia. All the apraxia variables are significant as predictors of subsequent dependency. The results show the seriousness of problems related to apraxia in rehabilitation of stroke patients with a lesion in the left hemisphere. One conclusion is that the treatment procedure ought to be directed to the various symptoms of apraxia. The effect of apraxia on ADL in the domestic situation has to be given more attention. More treatment should be given in the home, as patients seem to have difficulty in transferring the skills learned in hospital to the home situation and in maintaining them.

Activities of Daily Living↗
PubMed1998

Ideomotor apraxia test: a new test of imitation of gestures for elderly people.

Ideomotor apraxia is one of the earliest disturbances in Alzheimer's disease (AD); no test of this disturbance has yet been validated for elderly people. We propose a test of meaningless gesture imitation and its relevance in elderly people is studied. The Ideomotor Apraxia Test (IAT) consists of showing 10 gestures. Each item is graded from 0 to 3. IAT was carried out on 55 patients with AD (mean age: 86.8 +/- 6.8 (71-100); mean MMS score: 14.6 +/- 6.3) and 26 elderly patients without cognitive impairment (mean age: 84.1 +/- 7.5 (70-100); mean MMS score: 27.5 +/- 1.9). The inter-rater reliability, a threshold, the apparent sensitivity and specificity and the relationship between the MMS score and the ideomotor apraxia score were determined. The mean apraxia score was 14.9 +/- 7.3 in the AD group and 28 +/- 1.6 in the normal group (P < 0.0001). Inter-rater agreement is excellent (P = 0.995). The threshold is 27. The apparent sensitivity and specificity are very good (95% and 88%, respectively). The correlation between the MMS score and ideomotor apraxia score is excellent (r = 0.83 (95% CI; 0.72-0.91). Age and educational level do not influence ideomotor apraxia score. IAT is the first test that evaluates meaningless gesture imitating capacity in an elderly population. It is an easy and quick-to-perform test, useful routinely for diagnosis of AD. It could contribute to the early diagnosis of AD and is correlated with the severity of cognitive impairment. Copyright 1998 Lippincott Williams & Wilkins

Journal Article↗
PubMed1998

Functional brain imaging in apraxia.

BACKGROUND: An extensive literature describes structural lesions in apraxia, but few studies have used functional neuroimaging. We used positron emission tomography (PET) to characterize relative cerebral glucose metabolism in a 65-year-old, right-handed woman with progressive decline in ability to manipulate objects, write, and articulate speech. OBJECTIVE: To characterize functional brain organization in apraxia. DESIGN AND METHODS: The patient underwent a neurological examination, neuropsychological testing, magnetic resonance imaging, and fludeoxyglucose F 18 PET. The patient's magnetic resonance image was coregistered to her PET image, which was compared with the PET images of 7 right-handed, healthy controls. Hemispheric regions of interest were normalized by calcrine cortex. RESULTS: Except for apraxia and mild grip weakness, results of the neurological examination were normal. There was ideomotor apraxia of both hands (command, imitation, and object) and buccofacial apraxia. The patient could recognize meaningful gestures performed by the examiner and discriminate between his accurate and awkward pantomime. The magnetic resonance image showed moderate generalized atrophy and mild ischemic changes. Positron emission tomographic scans showed abnormal fludeoxyglucose F 18 uptake in the posterior frontal, supplementary motor, and parietal regions, the left affected more than the right. Focal metabolic deficit was present in the angular gyrus, an area hypothesized to store conceptual knowledge of skilled movement. CONCLUSIONS: Greater parietal than frontal physiological dysfunction and preserved gesture recognition are not consistent with the theory that knowledge of limb praxis is stored in the dominant parietal cortex. Gesture comprehension may be more diffusely distributed.

Aged↗
PubMed2004

Imaging a cognitive model of apraxia: the neural substrate of gesture-specific cognitive processes.

The present study aimed to ascertain the neuroanatomical basis of an influential neuropsychological model for upper limb apraxia [Rothi LJ, et al. The Neuropsychology of Action. 1997. Hove, UK: Psychology Press]. Regional cerebral blood flow was measured in healthy volunteers using H2 15O PET during performance of four tasks commonly used for testing upper limb apraxia, i.e., pantomime of familiar gestures on verbal command, imitation of familiar gestures, imitation of novel gestures, and an action-semantic task that consisted in matching objects for functional use. We also re-analysed data from a previous PET study in which we investigated the neural basis of the visual analysis of gestures. First, we found that two sets of discrete brain areas are predominantly engaged in the imitation of familiar and novel gestures, respectively. Segregated brain activation for novel gesture imitation concur with neuropsychological reports to support the hypothesis that knowledge about the organization of the human body mediates the transition from visual perception to motor execution when imitating novel gestures [Goldenberg Neuropsychologia 1995;33:63-72]. Second, conjunction analyses revealed distinctive neural bases for most of the gesture-specific cognitive processes proposed in this cognitive model of upper limb apraxia. However, a functional analysis of brain imaging data suggested that one single memory store may be used for "to-be-perceived" and "to-be-produced" gestural representations, departing from Rothi et al.'s proposal. Based on the above considerations, we suggest and discuss a revised model for upper limb apraxia that might best account for both brain imaging findings and neuropsychological dissociations reported in the apraxia literature.

Adult↗
PubMed1999

Apraxia differs in corticobasal degeneration and left-parietal stroke: A case study.

Corticobasal degeneration (CBD) is a progressive disorder characterized by both cortical and basal ganglia dysfunction such as asymmetrical apraxia, and akinetic rigidity, involuntary movements, and cortical sensory loss. Although apraxia is a key finding for the differential diagnosis of CBD, it has not been determined whether the features of apraxia seen in subjects with CBD are similar to those features exhibited by subjects with left-hemisphere damage from stroke. Therefore, for both clinical purposes and in order to better understand the brain mechanisms that lead to apraxia in CBD, we studied praxis in a patient with CBD and compared him to patients who are apraxic from left-parietal strokes. We used three-dimensional movement analyses to compare the features of apraxic movement. This subject with CBD was a dentist whose initial complaint had been that he "forgot" how to use his tools in the mouths of his patients. Analyses were performed on the trajectories made when using a knife to actually slice bread, and when repetitively gesturing slicing made to verbal command. Movements of the left hand, wrist, elbow, and shoulder were digitized in 3-D space. Although the CBD subject was clearly apraxic, the features of his apraxia differed markedly from those of the subjects with lesions in the left parietal lobe. For movements to command, the CBD subject showed joint coordination deficits, but his wrist trajectories were produced in the appropriate spatial plane, were correctly restricted to a single plane, and, like control subjects, were linear in path shape. However, when he was actually manipulating the tool and object, all of these aspects of his trajectories became impaired. In contrast, the deficits of the apraxic subjects with left-parietal damage were most pronounced to verbal command with their movements improving slightly although remaining impaired during actual tool and object manipulation. Unlike patients with parietal strokes, patients with CBD have degeneration in several systems and perhaps deficits in these other areas may account for the differences in praxic behavior.

Aged↗
PubMed2001

Limb apraxia: cortical or subcortical.

Ideomotor apraxia is defined as a disturbance in timing, sequencing, and spatial organization of gestural movements. Left hemisphere motor dominance reflected by ideomotor apraxia mainly refers to spatially and temporally complex movements performed outside the natural context. While clinicoanatomical studies have failed to unveil a specific lesion correlating with apraxia, white matter damage-interrupting corticocortical and corticosubcortical connections-seems crucial for the deficit to be persistent and severe. Patients with basal ganglia lesions and disorders, such as Parkinson's disease and progressive supranuclear palsy, may exhibit ideomotor apraxia. The putative roles of the basal ganglia in object-oriented action, and therefore in praxis, would include among others (a) the selection of the kinematic parameters and the direction of arm movements, (b) working as an integral part of brain systems involved in timing and representation of action sequences, (c) encoding behavioral context, and (d) working as a subcortical component of the parietofrontal circuits devoted to sensorimotor transformation (e.g., reaching). Several studies suggest that basal ganglia pathology per se may not cause overt apraxia. However, when it is combined with dysfunction of the cortical components of the neural systems involved in sequencing, sensorimotor transformation, and response selection, different types of ideomotor praxis deficits would become clinically manifested.

Apraxia, Ideomotor↗
PubMed2003

Distal-proximal differences in limb apraxia in corticobasal degeneration but not progressive supranuclear palsy.

Limb apraxia is an important diagnostic sign of cortico-basal degeneration (CBD), although it is also found in progressive supranuclear palsy (PSP). We investigated whether the severity of apraxia differed between proximal and distal arm movements in the two diseases, as suggested by their differing patterns of motor impairment. We studied 24 CBD patients, 25 PSP patients, and 19 healthy controls using a battery of cognitive tests and an ideomotor apraxia test that examined imitation of hand and of whole arm gestures separately. CBD and PSP patients did not differ in general characteristics or disability and were similarly impaired in cognitive performance. Within-group differences between distal and proximal gesture scores were significant only for CBD patients ( p=0.007), in whom distal movements were more compromised. This finding suggests the presence of limb kinetic apraxia in CBD, perhaps in association with ideomotor apraxia.

Activities of Daily Living↗
PubMed1982

Praxis and language: the extent and variety of apraxia in aphasia.

This quantitative study of apraxia in aphasics establishes the extent and characteristics of apraxia in various aphasic groups, the differences between various categories of praxis, and the correlation between praxis and language parameters. Broca's aphasics have more severe apraxia than Wernicke's aphasics even though their comprehension is significantly better. Apraxia, however, correlates best with comprehension deficit and secondly with the severity of aphasia. Among the nonverbal parameters, drawing shows the highest correlations. Our study confirms the prominence of facial apraxia in Broca's aphasia. Praxis and language are closely related and appear to share the same neural structures.

Aphasia↗
PubMed1995

Imitating gestures and manipulating a mannikin--the representation of the human body in ideomotor apraxia.

Imitation of meaningless gestures was examined in patients with left brain damage (LBD), right brain damage (RBD) and controls. In addition to imitation on the own body, patients were asked to replicate the gestures on a life-sized mannikin. Manual dexterity was assessed by manipulation of beads, and general visuospatial abilities by block-design. LBD patients who displayed apraxia when imitating gestures on their own bodies scored dramatically worse than any other group when imitation was assessed on the mannikin. By contrast, on block-design and manipulation of beads patients with RBD were inferior not only to LBD patients without apraxia but also to apractic patients. Analysis of CT scans revealed that apraxia occurred with frontal, parietal and deep lesions, and that the impairment on the manipulation of the mannikin was present regardless of lesion site. The results support the contention that the basic deficit underlying impaired imitation of meaningless gestures in apraxia is to be sought at a conceptual level. Possibly, patients with apraxia are not able to evoke and represent conceptual knowledge about the human body which is necessary for performing the apparently simple task of imitating gestures.

Aged↗