FDG-PET patterns associated with ideomotor apraxia and imitation apraxia in patients with corticobasal syndrome.

INTRODUCTION: Apraxia is a core clinical feature of corticobasal syndrome (CBS). Among the subtypes of apraxia, ideomotor and imitation apraxia are frequently found in CBS. However, little is known about the brain networks that are characteristic of each apraxia subtype or their clinical implication. In this study, we used 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) to explore the specific patterns of glucose hypometabolism that are characteristic of apraxia subtypes by focusing on ideomotor and imitation apraxia. METHODS: We compared the areas of glucose hypometabolism in the brains of 52 patients with CBS and 13 healthy controls, both as a whole and according to apraxia subtypes. In addition, we investigated the relationship between the apraxia subtypes and the clinical phenotype of CBS. RESULTS: In patients with CBS, common hypometabolism was observed in the frontal gyrus, precentral gyrus and caudate regardless of apraxia subtypes. In particular, ideomotor apraxia was associated with hypometabolism in the angular gyrus, while imitation apraxia was associated with hypometabolism in the posterior part including the postcentral gyrus, precuneus, and posterior cingulate gyrus. Patients who showed both ideomotor and imitation apraxia were more likely to show the typical features of CBS and progressive supranuclear palsy compared with patients showing only one type of apraxia. CONCLUSION: Group comparison analysis using FDG-PET revealed distinct pathways of ideomotor and imitation apraxia in CBS. These findings add to our understanding of the brain networks underlying apraxia in association with the clinical features of CBS.

Motor recovery of hemiparetic leg by improvement of limb-kinetic apraxia in a chronic patient with traumatic brain injury: A case report.

RATIONALE: Limb-kinetic apraxia (LKA), a kind of apraxia, means the inability to perform precise and voluntary movements of extremities resulting from injury of the premotor cortex (PMC) or the corticofugal tract (CFT) from the PMC. Diagnosis of LKA is made by observation of movements without specific assessment tools. PATIENT CONCERNS: A 44-year-old male underwent conservative management for traumatic intracerebral hemorrhage in the left basal ganglia and subarachnoid hemorrhage due to a pedestrian-car crash. When he was admitted to the rehabilitation department of a university hospital after 41 months after onset, he presented with right hemiparesis (Medical Research Council (MRC): shoulder abductor; 3, elbow flexor; 3, finger extensor; 0, hip flexor; 2- [range: 30°], knee extensor; 1 and ankle dorsiflexor; 3-). In addition, he exhibited slow, clumsy, and mutilated movements when performing movements of his right ankle. DIAGNOSES: The patient was diagnosed as traumatic brain injury (TBI). INTERVENTIONS: Clinical assessments and DTI were performed at 41 and 44 months after onset. During three months, rehabilitative therapy was performed including dopaminergic drugs (pramipexole 2.5 mg, ropinirole 2.5 mg, and amantadine 300 mg, and carbidopa/levodopa 75 mg/750 mg). OUTCOMES: The right leg weakness slowly recovered during 3 months, until 44 months after the initial injury (MRC: shoulder abductor, 3; elbow flexor, 3; finger extensor, 0; hip flexor, 3; knee extensor, 3; and ankle dorsiflexor, 3+). The fiber number of the right corticospinal tract (CST) was decreased on 44-month diffusion tensor tractography (DTT) (1319) compared with 41-month DTT (1470) and the left CST was not reconstructed on both DTTs. The fiber number of both CRTs were decreased on 44-month DTT (right: 1547, left: 698) than 41-month DTT (right: 3161, left: 1222). LESSONS: A chronic patient with TBI showed motor recovery of the hemiparetic leg by improvement of LKA after rehabilitation. This results have important implications for neurorehabilitation.

The Effectiveness of Action Observation Therapy Based on Mirror Neuron Theory in Chinese Patients with Apraxia of Speech after Stroke.

OBJECTIVE: The present study aimed to evaluate the efficacy of action observation therapy (AOT) on apraxia of speech (AOS) in patients after stroke. MATERIALS AND METHODS: Forty-two patients diagnosed with AOS after stroke were randomly divided into an experimental group (n = 21) and a control group (n = 21). Both groups received 30 min of conventional language therapy twice daily, 5 days a week for 4 weeks. The patients in the experimental group additionally received 20 min of AOT before 10 min language therapy each day. The speech function and aphasia severity of the 2 groups were assessed using the speech apraxia assessment method of the China Rehabilitation Research Center, Western Aphasia Battery (WAB), and the Boston Diagnostic Aphasia Examination before and after treatment. RESULTS: AOS and WAB scores increased significantly after treatment in both groups (p < 0.05). AOS and WAB scores exhibited significant differences between the experimental group and the control group after training (p < 0.05). The response rate in the experimental group was significantly higher than that in the control group (p < 0.05). CONCLUSION: AOT based on mirror neuron theory may improve language function in patients with AOS after stroke.

A progressive breakdown of the body in space.

A 74 year-old woman (MD), free of previous neurological history, presented with difficulty in handling cutlery, clothes, writing with what was initially described as an atypical apraxia in acts related to space. Initial neurological evaluation revealed mixed, asymmetric pyramidal, and extrapyramidal semiology. Νeuropsychological testing revealed dressing and constructional deficits, ideomotor apraxia and signs of executive dysfunction in absence of memory, language, and visual perception pathology. The final diagnosis was that of a corticobasal degeneration, where the rare occurrence of a progressively emerging syndrome of self-management loss within peripersonal space is observed.

Deficient supplementary motor area at rest: Neural basis of limb kinetic deficits in Parkinson's disease.

Parkinson's disease (PD) patients frequently suffer from limb kinetic apraxia (LKA) affecting quality of life. LKA denotes an impairment of precise and independent finger movements beyond bradykinesia, which is reliably assessed by coin rotation (CR) task. BOLD fMRI detected activation of a left inferior parietal-premotor praxis network in PD during CR. Here, we explored which network site is most critical for LKA using arterial spin labeling (ASL). Based on a hierarchical model, we hypothesized that LKA would predominantly affect the functional integrity of premotor areas including supplementary motor areas (SMA). Furthermore, we suspected that for praxis function with higher demand on temporal-spatial processing such as gesturing, inferior parietal lobule (IPL) upstream to premotor areas would be essential. A total of 21 PD patients and 20 healthy controls underwent ASL acquisition during rest. Behavioral assessment outside the scanner involved the CR, finger tapping task, and the test of upper limb apraxia (TULIA). Whole-brain analysis of activity at rest showed a significant reduction of CR-related perfusion in the left SMA of PD. Furthermore, the positive correlation between SMA perfusion and CR, seen in controls, was lost in patients. By contrast, TULIA was significantly associated with the perfusion of left IPL in both patients and controls. In conclusion, the findings suggest that LKA in PD are linked to an intrinsic disruption of the left SMA function, which may only be overcome by compensatory network activation. In addition, gestural performance relies on IPL which remains available for functional recruitment in early PD.

Crossover learning of gestures in two ideomotor apraxia patients: A single case experimental design study.

Crossover learning may aid rehabilitation in patients with neurological disorders. Ideomotor apraxia (IMA) is a common sequela of left-brain damage that comprises a deficit in the ability to perform gestures to verbal commands or by imitation. This study elucidated whether crossover learning occurred in two post-stroke IMA patients without motor paralysis after gesture training approximately 2 months after stroke onset. We quantitatively analysed the therapeutic intervention history and investigated whether revised action occurred during gesture production. Treatment intervention was to examine how to influence improvement and generalisation of the ability to produce the gesture. This study used an alternating treatments single-subject design, and the intervention method was errorless learning. Results indicated crossover learning in both patients. Qualitative analysis indicated that revised action occurred during the gesture-production process in one patient and that there were two types of post-revised action gestures: correct and incorrect gestures. We also discovered that even when a comparably short time had elapsed since stroke onset, generalisation was difficult. Information transfer between the left and right hemispheres of the brain via commissural fibres is important in crossover learning. In conclusion, improvements in gesture-production skill should be made with reference to the left cerebral hemisphere disconnection hypothesis.

Dysfunction of the Human Mirror Neuron System in Ideomotor Apraxia: Evidence from Mu Suppression.

Stroke patients with ideomotor apraxia (IMA) have difficulties controlling voluntary motor actions, as clearly seen when asked to imitate simple gestures performed by the examiner. Despite extensive research, the neurophysiological mechanisms underlying failure to imitate gestures in IMA remain controversial. The aim of the current study was to explore the relationship between imitation failure in IMA and mirror neuron system (MNS) functioning. Mirror neurons were found to play a crucial role in movement imitation and in imitation-based motor learning. Their recruitment during movement observation and execution is signaled in EEG recordings by suppression of the lower (8-10 Hz) mu range. We examined the modulation of EEG in this range in stroke patients with left (n = 21) and right (n = 15) hemisphere damage during observation of video clips showing different manual movements. IMA severity was assessed by the DeRenzi standardized diagnostic test. Results showed that failure to imitate observed manual movements correlated with diminished mu suppression in patients with damage to the right inferior parietal lobule and in patients with damage to the right inferior frontal gyrus pars opercularis-areas where major components of the human MNS are assumed to reside. Voxel-based lesion symptom mapping revealed a significant impact on imitation capacity for the left inferior and superior parietal lobules and the left post central gyrus. Both left and right hemisphere damages were associated with imitation failure typical of IMA, yet a clear demonstration of relationship to the MNS was obtained only in the right hemisphere damage group. Suppression of the 8-10 Hz range was stronger in central compared with occipital sites, pointing to a dominant implication of mu rather than alpha rhythms. However, the suppression correlated with De Renzi's apraxia test scores not only in central but also in occipital sites, suggesting a multifactorial mechanism for IMA, with a possible impact for deranged visual attention (alpha suppression) beyond the effect of MNS damage (mu suppression).

Ideomotor Apraxia Due to Injury of the Superior Longitudinal Fasciculus.

We report on a patient who showed ideomotor apraxia due to injury of the superior longitudinal fasciculus following brain tumor and tumor bleeding, which was demonstrated by diffusion tensor tractography (DTT). A 60-yr-old, right-handed male patient underwent removal of brain meningioma and drainage of intraventricular hemorrhage and intracerebral hemorrhage in the left fronto-parietal lobe. At the time of DTT scanning (5 wk after onset), he was able to move the right upper extremity against gravity. The patient exhibited an intact ideational plan for motor performance. In addition, he was able to use actual objects (scissors, eraser) using his right wrist and hand. However, he had difficulty in using his right upper extremity for pantomime of object use, imitating gestures (meaningless or meaningful), and movement of his right upper extremity proximal. Score on the ideomotor apraxia test for the right side was 4 (cut-off score < 32). DTTs for the left superior longitudinal fasciculus to the left premotor cortex and left inferior parietal lobule showed partial injury, compared with the right superior longitudinal fasciculus. These injuries appeared to be the reason for ideomotor apraxia in this patient.

Callosal apraxia: a 34-year follow-up study.

Loss of ability of the left upper limb (LUL) to correctly produce spatial and temporal components of skilled purposeful movements was reported 34 years ago in a woman with a callosal infarction. To learn about recovery, we recently reexamined this woman. This woman was tested for ideomotor apraxia by asking her to pantomime to command and to seeing pictures of tools. Whereas she performed normally with her right upper limb, her LUL remained severely apraxic, making many spatial (postural and movement) errors. Initially, she did not reveal loss of finger-hand deftness (limb-kinetic apraxia), and when tested again with the coin rotation task, her left hand performance was normal. Without vision, she could name objects placed in her left hand but not name numbers written in this hand. Since this woman had a callosal lesion, failure to recover cannot be accounted for by left hemisphere inhibition of her right hemisphere. Although failure for her LUL to improve may have been related to not using her LUL for skilled actions, her right hemisphere was able to observe transitive actions, and this failure of her LUL to produce skilled purposeful movements suggests her right hemisphere may have not had the capacity to learn these movement representations. Without vision, her ability to recognize objects with her left hand, but not numbers written on her left palm, suggests graphesthesia may require that her left hand did not have access to movement representations important for programming these numbers when writing.

Left parietal cortex transcranial direct current stimulation enhances gesture processing in corticobasal syndrome.

BACKGROUND AND PURPOSE: Corticobasal syndrome (CBS) is a clinical entity characterized by higher cortical dysfunctions associated with asymmetric onset of levodopa-resistant parkinsonism, dystonia and myoclonus. One of the most typical and distressful features of CBS is limb apraxia, which affects patients in their everyday life. Transcranial direct current stimulation (tDCS) is a non-invasive procedure of cortical stimulation, which represents a promising tool for cognitive enhancement and neurorehabilitation. The present study investigated whether anodal tDCS over the parietal cortex (PARC), would improve ideomotor upper limb apraxia in CBS patients. METHODS: Fourteen patients with possible CBS and upper limb apraxia were enrolled. Each patient underwent two sessions of anodal tDCS (left and right PARC) and one session of placebo tDCS. Ideomotor upper limb apraxia was assessed using the De Renzi ideomotor apraxia test that is performed only on imitation. RESULTS: A significant improvement of the De Renzi ideomotor apraxia test scores (post-stimulation versus pre-stimulation) after active anodal stimulation over the left PARC was observed (χ(2) = 17.6, P = 0.0005), whilst no significant effect was noticed after active anodal stimulation over the right PARC (χ(2) = 7.2, P = 0.07). A post hoc analysis revealed a selective improvement in the De Renzi ideomotor apraxia score after active anodal stimulation over the left PARC compared with placebo stimulation considering both right (P = 0.03) and left upper limbs (P = 0.01). CONCLUSIONS: These findings indicate that tDCS to the PARC improves the performance of an ideomotor apraxia test in CBS patients and might represent a promising tool for future rehabilitation approaches.

Association of ideomotor apraxia with lesion site, etiology, neglect, and functional independence in patients with first ever stroke.

BACKGROUND: Ideomotor apraxia (IMA) is characterized by the inability to correctly imitate hand gestures and voluntarily pantomime tool use. The relationship between IMA and characteristics of stroke has not been totally elucidated. OBJECTIVE: This study aimed to find out associations between presence of IMA and stroke etiology, site of the lesions, neglect, and temporal and functional parameters of stroke in patients with first ever stroke. METHODS: Thirty-nine patients with first ever stroke were included. Patients with severe cognitive deficits were excluded. Assessment tools included Ideomotor Apraxia Test, Functional Independence Measure (FIM), Brunnstrom recovery stages, Mini Mental Test (MMT), and star cancellation test. Etiology (hemorrhagic or ischemic) and site of stroke was assessed through brain imaging methods. Location and size of ischemic lesion was determined by using the Oxfordshire Community Stroke Project system. RESULTS: IMA was identified in 35.9% of the patients. Patients with IMA had significantly lower FIM scores both on admission and discharge (P = 0.001, P = 0.001). Presence of IMA was significantly associated with the presence of neglect (P = 0.004), total anterior circulation ischemia (TACI) (P < 0.001), and lower MMT scores (P < 0.001). Lesion site, patient age, time since onset, and stroke etiology had no impact on the presence of IMA. CONCLUSION: IMA was in concordance with poor cognitive and functional state and was not limited to left hemisphere lesions. The study revealed strong associations between IMA, neglect, and TACI. Every patient with stroke should be evaluated for the presence of IMA on admission to rehabilitation unit.

Limb apraxia in multiple sclerosis.

BACKGROUND/AIM: There are almost no studies on apraxia in people with multiple sclerosis. Although the white matter is damaged in MS, it is not the only location in which the pathological changes are present. Demyelinated lesions in the cortex have recently been recognized as important components of multiple sclerosis pathology. The aim of this study was to determine whether apraxia is present among people with MS, and the importance of demographic characteristics and impairment of functional systems at conceptualization and execution of movements. METHODS: The experimental group consisted of 30 patients, mean age 51.34 +/- 7.70 years. The patients in the experimental group were diagnosed with MS according to the McDonald criteria. The control group consisted of 30 healthy subjects, mean age 50.30 +/- 10.47 years. For research purposes, we used the following instruments: Questionnaire for Collecting Demographic Data, Kurtzke Functional Systems Scores, Waterloo-Sunnybrook Apraxia Battery (WatAB). Execution of motion tasks that are a part of the WatAB were incorporated in the System for the Observation and Analysis of Motor Behavior. RESULTS: Our study showed that limb apraxia was common in people with MS. Apraxia was present during pantomime in 26.70% of the patients, and during the imitation of movements in 44.80% of the patients. Gender, age, education level, duration of disease and a form of MS did not determine the quality of conceptualization and execution of movements. The time elapsed from the last exacerbation was a determinant of quality of executed movements. Impairments of functional systems predicted impairments of movement execution. The expanded disability scale score correlated with the severity of apraxia. CONCLUSION: Our study confirm the presence of apraxia in MS. It is necessary to carry out further studies using functional magnetic resonance imaging, as well as the conduct longitudinal studies to determine the precise structure of motor behavior in people with MS.

Limb apraxia and verb processing in Alzheimer's disease.

OBJECTIVE: The present research investigates language and praxis abilities in patients with Alzheimer's disease in order to study the relationship between these two cognitive domains. METHOD: The experimental evaluation of patients and control group performance was designed to permit a direct comparison of linguistic abilities (i.e., verb and noun naming and sentence comprehension) and praxic abilities (i.e., gesture execution for complex movements). Moreover, for the first time, action comprehension was explored using the Action Sequence Comprehension. RESULTS AND CONCLUSION: Analyses of variance (ANOVAs) and correlational analyses showed that a direct relationship may exist between language impairment and apraxia in patients with Alzheimer's disease. In addition, the production and comprehension of both language and action were equally impaired in patients, providing further evidence for a spectrum of concomitant linguistic and praxis deficits in Alzheimer's disease. Finally, the ability to correctly comprehend action semantics was related more directly to verb production ability than to noun production.

Motor recovery by improvement of limb-kinetic apraxia in a chronic stroke patient.

OBJECTIVES: We report on a chronic stroke patient who showed motor recovery by improvement of limb-kinetic apraxia (LKA) after undergoing intensive rehabilitation for a period of one month, which was demonstrated by diffusion tensor tractography (DTT) and transcranial magnetic stimulation (TMS). METHODS: A 50-year-old male patient presented with severe paralysis of the left extremities at the onset of thalamic hemorrhage. At thirty months after onset, the patient exhibited moderate weakness of his left upper and lower extremities. In addition, he exhibited a slow, clumsy, and mutilated movement pattern during grasp-release movements of his left hand. During a one-month period of intensive rehabilitation, which was started at thrity months after onset, the patient showed 22% motor recovery of the left extremities. The slow, clumsy, and mutilated movement pattern of the left hand almost disappeared. RESULTS: DTTs of the corticospinal tract (CST) in both hemispheres originated from the cerebral cortex, including the primary motor cortex, and passed along the known CST pathway. The DTT of the right CST was located anterior to the old hemorrhagic lesion. TMS study performed at thirty and thirty-one months after onset showed normal and similar findings for motor evoked potential in terms of latency and amplitude of the left hand muscle. CONCLUSIONS: We think that the motor weakness of the left extremities in this patient was mainly ascribed to LKA and that most of the motor recovery during a one-month period of rehabilitation was attributed to improvement of LKA.

Isolated buccofacial apraxia subsequent to a left ventral premotor cortex infarction.

Buccofacial apraxia (BFA, or oral apraxia) is a nonspeech skilled movement disorder that involves orofacial structures in the absence of paresis. BFA usually co-occurs with aphasia or apraxia of speech (AOS) and isolated BFA is an extremely rare phenomenon. The brain regions correlated with BFA have been studied in patients with concomitant aphasia or limb apraxia. Therefore, the exact brain regions responsible for BFA remain unclear. We report a patient with pure BFA and discuss the localization of the brain lesion.

Teaching video neuroimages: callosal apraxia: a straightforward model of ideomotor apraxia.

A 57-year-old right-handed man complained of difficulty using his hands post-coronary artery bypass graft (figure). Neurologic examination revealed signs of callosal disconnection without hemiparesis. When asked to perform limb gestures like "brush your teeth" or "wave goodbye," the right hand performed flawlessly whereas the left hand was severely apraxic (video on the Neurology Web site at www.neurology.org).

Response interference between functional and structural object-related actions is increased in patients with ideomotor apraxia.

We report data from two left hemisphere stroke patients with moderate-to-severe ideomotor apraxia who exhibited deficits in positioning their hands to use 'conflict' objects (objects grasped and used with different hand postures) relative to controls and patients with mild apraxia. These novel data support the claim that actions to common objects are subject to interference between multiple responses, and suggest that errors in apraxia may be attributed to deficient resolution of competition between appropriate and inappropriate actions.

[A 68 year-old man presenting ideomotor apraxia and incomplete Gerstmann syndrome with multiple cystic lesions in the left hemisphere].

A 68-year-old man was referred to our hospital with tension-type headaches and a 1-year history of dementia. On neurologic examination, he had ideomotor apraxia and incomplete Gerstmann syndrome that was characterized by acalculia, agraphia, and finger agnosia. On imaging, multiple cystic lesions reported as "unusually dilated perivascular spaces" were observed along the medullary arteries in the left hemisphere; some of them had adjacent hyperintense areas in fluid attenuated inversion recovery images. We assumed that the multiple cystic lesions caused his higher cerebral dysfunction, because ideomotor apraxia and Gerstmann syndrome are usually indicative of a left parietal lobe lesion. MR spectroscopy in the lesion site revealed increased lactate. On MR angiography, the left middle cerebral artery and the left posterior cerebral artery were poorly visualized without localized stenosis. Technetium-99 bicisate single-photon emission computed tomography showed severely decreased cerebral blood flow in the left hemisphere. Electroencephalography showed slow waves in the left hemisphere.

Cognitive performance is impaired in coeliac patients on gluten free diet: a case-control study in patients older than 65 years of age.

INTRODUCTION: Retrospective studies and case reports suggest an association between coeliac disease and impaired cognitive function. AIM: To evaluate functional and cognitive performances in coeliac disease vs. control patients older than 65 years. METHOD: Eighteen coeliac disease patients (75±4 years, group A) on gluten free diet since 5.5±3 years and 18 age-sex matched controls (76±4 years, group B) were studied using a battery of neuropsychological tests. Results of functional and cognitive tests are expressed as "row scores" and as "equivalent scores" by relating "raw scores" to reference rank categories. RESULTS: Barthel Index of functional performance was similar in the 2 groups. "Raw score" was significantly lower in coeliac disease than controls for Mini Mental Test Examination (p=0.02), Trail Making Test (p=0.001), Semantic Fluency (p=0.03), Digit Symbol Test (p=0.007), Ideo-motor apraxia (p<0.001) and Bucco-facial apraxia (p<0.002). "Equivalent score" was also lower in coeliac disease than controls for Semantic memory (p<0.01) and for Ideo-motor apraxia (p=0.007). CONCLUSION: Cognitive performance is worse in elderly coeliac disease than control patients, despite prolonged gluten avoidance in coeliacs. Awareness on the increasing phenomenon of late-onset coeliac disease is important to minimize diagnostic delay and prolonged exposure to gluten that may adversely and irreversibly affect cognitive function.