The parietal architecture binding cognition to sensorimotor integration: a multimodal causal study.

Despite human's praxis abilities are unique among primates, comparative observations suggest that these cognitive motor skills could have emerged from exploitation and adaptation of phylogenetically older building blocks, namely the parieto-frontal networks subserving prehension and manipulation. Within this framework, investigating to which extent praxis and prehension-manipulation overlap and diverge within parieto-frontal circuits could help in understanding how human cognition shapes hand actions. This issue has never been investigated by combining lesion mapping and direct electrophysiological approaches in neurosurgical patients. To this purpose, 79 right-handed left-brain tumour patient candidates for awake neurosurgery were selected based on inclusion criteria. First, a lesion mapping was performed in the early postoperative phase to localize the regions associated with an impairment in praxis (imitation of meaningless and meaningful intransitive gestures) and visuo-guided prehension (reaching-to-grasping) abilities. Then, lesion results were anatomically matched with intraoperatively identified cortical and white matter regions, whose direct electrical stimulation impaired the Hand Manipulation Task. The lesion mapping analysis showed that prehension and praxis impairments occurring in the early postoperative phase were associated with specific parietal sectors. Dorso-mesial parietal resections, including the superior parietal lobe and precuneus, affected prehension performance, while resections involving rostral intraparietal and inferior parietal areas affected praxis abilities (covariate clusters, 5000 permutations, cluster-level family-wise error correction P < 0.05). The dorsal bank of the rostral intraparietal sulcus was associated with both prehension and praxis (overlap of non-covariate clusters). Within praxis results, while resection involving inferior parietal areas affected mainly the imitation of meaningful gestures, resection involving intraparietal areas affected both meaningless and meaningful gesture imitation. In parallel, the intraoperative electrical stimulation of the rostral intraparietal and the adjacent inferior parietal lobe with their surrounding white matter during the hand manipulation task evoked different motor impairments, i.e. the arrest and clumsy patterns, respectively. When integrating lesion mapping and intraoperative stimulation results, it emerges that imitation of praxis gestures first depends on the integrity of parietal areas within the dorso-ventral stream. Among these areas, the rostral intraparietal and the inferior parietal area play distinct roles in praxis and sensorimotor process controlling manipulation. Due to its visuo-motor 'attitude', the rostral intraparietal sulcus, putative human homologue of monkey anterior intraparietal, might enable the visuo-motor conversion of the observed gesture (direct pathway). Moreover, its functional interaction with the adjacent, phylogenetic more recent, inferior parietal areas might contribute to integrate the semantic-conceptual knowledge (indirect pathway) within the sensorimotor workflow, contributing to the cognitive upgrade of hand actions.

Longitudinal flortaucipir, metabolism and volume differ between phonetic and prosodic speech apraxia.

Progressive apraxia of speech (PAOS) is a neurodegenerative motor-speech disorder that most commonly arises from a four-repeat tauopathy. Recent studies have established that progressive apraxia of speech is not a homogenous disease but rather there are distinct subtypes: the phonetic subtype is characterized by distorted sound substitutions, the prosodic subtype by slow and segmented speech and the mixed subtype by a combination of both but lack of predominance of either. There is some evidence that cross-sectional patterns of neurodegeneration differ across subtypes, although it is unknown whether longitudinal patterns of neurodegeneration differ. We examined longitudinal patterns of atrophy on MRI, hypometabolism on 18F-fluorodeoxyglucose-PET and tau uptake on flortaucipir-PET in a large cohort of subjects with PAOS that had been followed for many years. Ninety-one subjects with PAOS (51 phonetic, 40 prosodic) were recruited by the Neurodegenerative Research Group. Of these, 54 (27 phonetic, 27 prosodic) returned for annual follow-up, with up to seven longitudinal visits (total visits analysed = 217). Volumes, metabolism and flortaucipir uptake were measured for subcortical and cortical regions, for all scans. Bayesian hierarchical models were used to model longitudinal change across imaging modalities with PAOS subtypes being compared at baseline, 4 years from baseline, and in terms of rates of change. The phonetic group showed smaller volumes and worse metabolism in Broca's area and the striatum at baseline and after 4 years, and faster rates of change in these regions, compared with the prosodic group. There was also evidence of faster spread of hypometabolism and flortaucipir uptake into the temporal and parietal lobes in the phonetic group. In contrast, the prosodic group showed smaller cerebellar dentate, midbrain, substantia nigra and thalamus volumes at baseline and after 4 years, as well as faster rates of atrophy, than the phonetic group. Greater hypometabolism and flortaucipir uptake were also observed in the cerebellar dentate and substantia nigra in the prosodic group. Mixed findings were observed in the supplementary motor area and precentral cortex, with no clear differences observed across phonetic and prosodic groups. These findings support different patterns of disease spread in PAOS subtypes, with corticostriatal patterns in the phonetic subtype and brainstem and thalamic patterns in the prosodic subtype, providing insight into the pathophysiology and heterogeneity of PAOS.

Clinical dimensions along the non-fluent variant primary progressive aphasia spectrum.

It is debated whether primary progressive apraxia of speech (PPAOS) and progressive agrammatic aphasia (PAA) belong to the same clinical spectrum, traditionally termed non-fluent/agrammatic variant primary progressive aphasia (nfvPPA), or exist as two completely distinct syndromic entities with specific pathologic/prognostic correlates. We analysed speech, language and disease severity features in a comprehensive cohort of patients with progressive motor speech impairment and/or agrammatism to ascertain evidence of naturally occurring, clinically meaningful non-overlapping syndromic entities (e.g. PPAOS and PAA) in our data. We also assessed if data-driven latent clinical dimensions with aetiologic/prognostic value could be identified. We included 98 participants, 43 of whom had an autopsy-confirmed neuropathological diagnosis. Speech pathologists assessed motor speech features indicative of dysarthria and apraxia of speech (AOS). Quantitative expressive/receptive agrammatism measures were obtained and compared with healthy controls. Baseline and longitudinal disease severity was evaluated using the Clinical Dementia Rating Sum of Boxes (CDR-SB). We investigated the data's clustering tendency and cluster stability to form robust symptom clusters and employed principal component analysis to extract data-driven latent clinical dimensions (LCD). The longitudinal CDR-SB change was estimated using linear mixed-effects models. Of the participants included in this study, 93 conformed to previously reported clinical profiles (75 with AOS and agrammatism, 12 PPAOS and six PAA). The remaining five participants were characterized by non-fluent speech, executive dysfunction and dysarthria without apraxia of speech or frank agrammatism. No baseline clinical features differentiated between frontotemporal lobar degeneration neuropathological subgroups. The Hopkins statistic demonstrated a low cluster tendency in the entire sample (0.45 with values near 0.5 indicating random data). Cluster stability analyses showed that only two robust subgroups (differing in agrammatism, executive dysfunction and overall disease severity) could be identified. Three data-driven components accounted for 71% of the variance [(i) severity-agrammatism; (ii) prominent AOS; and (iii) prominent dysarthria]. None of these data-driven LCDs allowed an accurate prediction of neuropathology. The severity-agrammatism component was an independent predictor of a faster CDR-SB increase in all the participants. Higher dysarthria severity, reduced words per minute and expressive and receptive agrammatism severity at baseline independently predicted accelerated disease progression. Our findings indicate that PPAOS and PAA, rather than exist as completely distinct syndromic entities, constitute a clinical continuum. In our cohort, splitting the nfvPPA spectrum into separate clinical phenotypes did not improve clinical-pathological correlations, stressing the need for new biological markers and consensus regarding updated terminology and clinical classification.

Localizing apraxia in corticobasal syndrome: a morphometric MRI study.

Apraxia localization has relied on voxel-based, lesion-symptom mapping studies in left hemisphere stroke patients. Studies on the neural substrates of different manifestations of apraxia in neurodegenerative disorders are scarce. The primary aim of this study was to look into the neural substrates of different manifestations of apraxia in a cohort of corticobasal syndrome patients (CBS) by use of cortical thickness. Twenty-six CBS patients were included in this cross-sectional study. The Goldenberg apraxia test (GAT) was applied. 3D-T1-weighted images were analyzed via the automated recon-all Freesurfer version 6.0 pipeline. Vertex-based multivariate General Linear Model analysis was applied to correlate GAT scores with cortical thickness. Deficits in imitation of meaningless gestures correlated with bilateral superior parietal atrophy, extending to the angular and supramarginal gyri, particularly on the left. Finger imitation relied predominantly on superior parietal lobes, whereas the left angular and supramarginal gyri, in addition to superior parietal lobes, were critical for hand imitation. The widespread bilateral clusters of atrophy in CBS related to apraxia indicate different pathophysiological mechanisms mediating praxis in neurodegenerative disorders compared to vascular lesions, with implications both for our understanding of praxis and for the rehabilitation approaches of patients with apraxia.

Integrated genome and transcriptome analyses reveal the mechanism of genome instability in ataxia with oculomotor apraxia 2.

Mutations in the SETX gene, which encodes Senataxin, are associated with the progressive neurodegenerative diseases ataxia with oculomotor apraxia 2 (AOA2) and amyotrophic lateral sclerosis 4 (ALS4). To identify the causal defect in AOA2, patient-derived cells and SETX knockouts (human and mouse) were analyzed using integrated genomic and transcriptomic approaches. A genome-wide increase in chromosome instability (gains and losses) within genes and at chromosome fragile sites was observed, resulting in changes to gene-expression profiles. Transcription stress near promoters correlated with high GCskew and the accumulation of R-loops at promoter-proximal regions, which localized with chromosomal regions where gains and losses were observed. In the absence of Senataxin, the Cockayne syndrome protein CSB was required for the recruitment of the transcription-coupled repair endonucleases (XPG and XPF) and RAD52 recombination protein to target and resolve transcription bubbles containing R-loops, leading to genomic instability. These results show that transcription stress is an important contributor to SETX mutation-associated chromosome fragility and AOA2.

Multimodal cross-examination of progressive apraxia of speech by diffusion tensor imaging-based tractography and Tau-PET scans.

Progressive apraxia of speech (PAOS) is a 4R tauopathy characterized by difficulties with motor speech planning. Neurodegeneration in PAOS targets the premotor cortex, particularly the supplementary motor area (SMA), with degeneration of white matter (WM) tracts connecting premotor and motor cortices and Broca's area observed on diffusion tensor imaging (DTI). We aimed to assess flortaucipir uptake across speech-language-related WM tracts identified using DTI tractography in PAOS. Twenty-two patients with PAOS and 26 matched healthy controls were recruited by the Neurodegenerative Research Group (NRG) and underwent MRI and flortaucipir-PET. The patient population included patients with primary progressive apraxia of speech (PPAOS) and non-fluent variant/agrammatic primary progressive aphasia (agPPA). Flortaucipir PET scans and DTI were coregistered using rigid registration with a mutual information cost function in subject space. Alignments between DTI and flortaucipir PET were inspected in all cases. Whole-brain tractography was calculated using deterministic algorithms by a tractography reconstruction tool (DSI-studio) and specific tracts were identified using an automatic fiber tracking atlas-based method. Fractional anisotropy (FA) and flortaucipir standardized uptake value ratios (SUVRs) were averaged across the frontal aslant tract, arcuate fasciculi, inferior frontal-occipital fasciculus, inferior and middle longitudinal fasciculi, as well as the SMA commissural fibers. Reduced FA (p < .0001) and elevated flortaucipir SUVR (p = .0012) were observed in PAOS cases compared to controls across all combined WM tracts. For flortaucipir SUVR, the greatest differentiation of PAOS from controls was achieved with the SMA commissural fibers (area under the receiver operator characteristic curve [AUROC] = 0.83), followed by the left arcuate fasciculus (AUROC = 0.75) and left frontal aslant tract (AUROC = 0.71). Our findings demonstrate that flortaucipir uptake is increased across WM tracts related to speech/language difficulties in PAOS.

The Neurocognitive Bases of Meaningful Intransitive Gestures: A Systematic Review and Meta-analysis of Neuropsychological Studies.

Researchers and clinicians have long used meaningful intransitive (i.e., not tool-related; MFI) gestures to assess apraxia-a complex and frequent motor-cognitive disorder. Nevertheless, the neurocognitive bases of these gestures remain incompletely understood. Models of apraxia have assumed that meaningful intransitive gestures depend on either long-term memory (i.e., semantic memory and action lexicons) stored in the left hemisphere, or social cognition and the right hemisphere. This meta-analysis of 42 studies reports the performance of 2659 patients with either left or right hemisphere damage in tests of meaningful intransitive gestures, as compared to other gestures (i.e., MFT or meaningful transitive and MLI or meaningless intransitive) and cognitive tests. The key findings are as follows: (1) deficits of meaningful intransitive gestures are more frequent and severe after left than right hemisphere lesions, but they have been reported in both groups; (2) we found a transitivity effect in patients with lesions of the left hemisphere (i.e., meaningful transitive gestures more difficult than meaningful intransitive gestures) but a "reverse" transitivity effect in patients with lesions of the right hemisphere (i.e., meaningful transitive gestures easier than meaningful intransitive gestures); (3) there is a strong association between meaningful intransitive and transitive (but not meaningless) gestures; (4) isolated deficits of meaningful intransitive gestures are more frequent in cases with right than left hemisphere lesions; (5) these deficits may occur in the absence of language and semantic memory impairments; (6) meaningful intransitive gesture performance seems to vary according to the emotional content of gestures (i.e., body-centered gestures and emotional valence-intensity). These findings are partially consistent with the social cognition hypothesis. Methodological recommendations are given for future studies.

De Novo GRID2 Variant as a Cause of Ataxia with Oculomotor Apraxia and Alpha-Fetoprotein Elevation.

Bi-allelic pathogenic variants in GRID2 have been initially associated to an autosomal recessive form of spinocerebellar ataxia, namely SCAR18. Subsequently, few monoallelic cases have been described. Here we present a new subject harboring a novel de novo heterozygous GRID2 missense variant presenting with progressive ataxia together with cerebellar atrophy and, for the first time, alpha-fetoprotein (AFP) elevation. We retrospectively collected data of the patient followed at our clinic. Genetic analysis was performed through clinical exome sequencing with an in-house in-silico ataxia-related genes panel. Variant effect prediction was performed through in silico modeling. The patient had normal psychomotor development except for mild fine and gross motor impairment. In adolescence, he started presenting dysarthria and progressive ataxia. Blood tests showed significant AFP elevation. Brain MRI showed cerebellar atrophy mainly involving the vermis. The novel de novo heterozygous GRID2 (c.1954C>A; p.Leu652Ile) missense variant was disclosed. This variant is located within a highly conserved site with low tolerance to variation and it is predicted to cause protein structure destabilization. GRID2 expression appears to be influenced by other genes related with ataxia and AFP elevation, like ATM and APTX, suggesting a possible shared mechanism. This additional patient increases the scarce literature and genotypic spectrum of the GRID2-related ataxia and evidences a fairly homogeneous phenotype of ataxia with oculomotor abnormalities for the autosomal-dominant form. Alfa-fetoprotein elevation is a novel finding in this condition and this data must be confirmed in larger case-series to definitively state that GRID2-related ataxia can be included among ataxias with AFP increase.

Mixed Aphasia Caused by Bilateral Cerebellar Infarcts: a Case Report.

Although neuroanatomical and physiological understanding of the cerebellum has evolved over recent decades and continues to develop, there is much that remains to be expounded upon, especially with regard to nonmotor roles. Neurocognitive and language processing is one area where involvement of the cerebellum is no longer in question, but the extent and mechanism of this relationship have yet to be defined. For example, which of the cerebellar hemispheres is involved continues to be debated. We present a case wherein a thrombus in the basilar artery led to bihemispheric cerebellar strokes with profound mixed effects on the patient's language and cognition. To the authors' knowledge, this is the first reported case of bilateral cerebellar strokes resulting in a mixed aphasia reported in scientific literature. This demonstrates the importance of continued research into a model for cerebellar function and the clinical impact of lesions to various cerebellar regions.

Knowing "what for," but not "where": Dissociation between functional and contextual tool knowledge in healthy individuals and patients with dementia.

OBJECTIVE: Semantic tool knowledge underlies the ability to perform activities of daily living. Models of apraxia have emphasized the role of functional knowledge about the action performed with tools (e.g., a hammer and a mallet allow a "hammering" action), and contextual knowledge informing individuals about where to find tools in the social space (e.g., a hammer and a mallet can be found in a workshop). The goal of this study was to test whether contextual or functional knowledge, would be central in the organization of tool knowledge. It was assumed that contextual knowledge would be more salient than functional knowledge for healthy controls and that patients with dementia would show impaired contextual knowledge. METHODS: We created an original, open-ended categorization task with ambiguity, in which the same familiar tools could be matched on either contextual or functional criteria. RESULTS: In our findings, healthy controls prioritized a contextual, over a functional criterion. Patients with dementia had normal visual categorization skills (as demonstrated by an original picture categorization task), yet they made less contextual, but more functional associations than healthy controls. CONCLUSION: The findings support a dissociation between functional knowledge ("what for") on the one hand, and contextual knowledge ("where") on the other hand. While functional knowledge may be distributed across semantic and action-related factors, contextual knowledge may actually be the name of higher-order social norms applied to tool knowledge. These findings may encourage researchers to test both functional and contextual knowledge to diagnose semantic deficits and to use open-ended categorization tests.

A new method for detecting unilateral spatial neglect with tracing tasks using the Rey-Osterrieth complex figure: a pilot study.

PURPOSE: To explore efficacy of the "Rey-Osterrieth complex figure (ROCF) tracing task" as a new test to detect unilateral spatial neglect (USN). METHODS: Subjects were 40 healthy control (HC) and 20 right brain-damaged patients with (USN + , n = 10) or without USN (USN - , n = 10). After the ROCF copying task, the tracing task was performed under conditions that did not leave any tracing lines on the sample figure. Evaluation used the conventional 36-point scoring system, laterality index (LI) as the ratio of the left and right structure scores, and the number of overlaps for each of the left and right structures scored. RESULTS: In the tracing task, USN + showed a lower LI than HC. Furthermore, left-sided neglect was sometimes more evident than in the copying task. Regarding the total overlapping score, USN + showed a greater score than HC. The right-sided overlapping scores in USN + and USN - were also greater than that in HC. In the right brain-damaged subjects, clinically meaningful correlations were not found between evaluations in the ROCF tracing task and in conventional USN screening tests. Receiver-operating-characteristic analysis to test the power of detection showed moderate performance for the tracing LI (AUC = 0.76, 95% CI = 0.54-0.97), which was greater than that of other tests. Further, the total overlapping score in the tracing task showed sensitivity 0.9 (highest among the tests performed), specificity 0.5, and AUC 0.68 (95% CI = 0.43-0.92). CONCLUSION: The ROCF tracing task might be a convenient method to detect USN and to reveal the extent of spatial working memory impairment.

Visuospatial memory in apraxia: Exploring quantitative drawing metrics to assess the representation of local and global information.

Neuropsychological evidence suggests that visuospatial memory is subserved by two separable processing systems, with dorsal underpinnings for global form and ventral underpinnings for the integration of part elements. Previous drawing studies have explored the effects of Gestalt organisation upon memory for hierarchical stimuli, and we here present an exploratory study of an apraxic dorsal stream patient's (MH) performance. We presented MH with a stimulus set (previously reported by Riddoch et al., Cognitive Neuropsychology, 20(7), 641-671, 2003) and devised a novel quantitative scoring system to obtain a finer grain of insight into performance. Stimuli possessed either good or poor Gestalt qualities and were reproduced in a copy condition and two visual memory conditions (with unlimited viewing before the model was removed, or with 3 s viewing). MH's copying performance was impaired in comparison to younger adult and age-matched older adult controls, with a variety of errors at the local level but relatively few at the global level. However, his performance in the visual memory conditions revealed impairments at the global level. For all participants, drawing errors were modulated by the Gestalt qualities of the stimuli, with accuracy at the global and local levels being lesser for poor global stimuli in all conditions. These data extend previous observations of this patient, and support theories that posit interaction between dorsal and ventral streams in the representation of hierarchical stimuli. We discuss the implications of these findings for our understanding of visuospatial memory in neurological patients, and also evaluate the application of quantitative metrics to the interpretation of drawings.

Considerations for identifying subtypes of speech sound disorder.

BACKGROUND: Speech sound disorders (SSDs) in children are heterogeneous. Differentiating children with SSDs into distinct subtypes is important so that each child receives a treatment approach well suited to the particular difficulties they are experiencing. AIMS: To study the distinct underlying processes that differentiate phonological processing, phonological planning or motor planning deficits. METHOD: The literature on the nature of SSDs is reviewed to reveal diagnostic signs at the level of distal causes, proximal factors and surface characteristics. MAIN CONTRIBUTION: Subtypes of SSDs may be identified by linking the surface characteristics of the children's speech to underlying explanatory proximal factors. The proximal factors may be revealed by measures of speech perception skills, phonological memory and speech-motor control. The evidence suggests that consistent phonological disorder (CPD) can be identified by predictable patterns of speech error associated with speech perception errors. Inconsistent phonological disorder (IPD) is associated with a deficit in the selection and sequencing of phonemes, that is, revealed as within-word inconsistency and poor phonological memory. The motor planning deficit that is specific to childhood apraxia of speech (CAS) is revealed by transcoding errors on the syllable repetition task and an inability to produce [pətəkə] accurately and rapidly. CONCLUSIONS & IMPLICATIONS: Children with SSDs form a heterogeneous population. Surface characteristics overlap considerably among those with severe disorders, but certain signs are unique to particular subtypes. Careful attention to underlying causal factors will support the accurate diagnosis and selection of personalized treatment options. WHAT THIS PAPER ADDS: What is already known on the subject SSD in children are heterogenous, with numerous subtypes of primary SSD proposed. Diagnosing the specific subtype of SSD is important in order to assign the most efficacious treatment approach for each child. Identifying the distinct subtype for each child is difficult because the surface characteristics of certain subtypes overlap among categories (e.g., CPD or IPD; CAS). What this paper adds to the existing knowledge The diagnostic challenge might be eased by systematic attention to explanatory factors in relation to the surface characteristics, using specific tests for this purpose. Word identification tasks tap speech perception skills; repetition of short versus long strings of nonsense syllables permits observation of phonological memory and phonological planning skills; and standard maximum performance tests provide considerable information about speech motor control. What are the potential or actual clinical implications of this work? Children with SSDs should receive comprehensive assessments of their phonological processing, phonological planning and motor planning skills frequently, alongside examinations of their error patterns in connected speech. Such assessments will serve to identify the child's primary challenges currently and as they change over developmental time.

A targeted review of prosodic production in agrammatic aphasia.

It is unclear whether individuals with agrammatic aphasia have particularly disrupted prosody, or in fact have relatively preserved prosody they can use in a compensatory way. A targeted literature review was undertaken to examine the evidence regarding the capacity of speakers with agrammatic aphasia to produce prosody. The aim was to answer the question, how much prosody can a speaker "do" with limited syntax? The literature was systematically searched for articles examining the production of grammatical prosody in people with agrammatism, and yielded 16 studies that were ultimately included in this review. Participant inclusion criteria, spoken language tasks, and analysis procedures vary widely across studies. The evidence indicates that timing aspects of prosody are disrupted in people with agrammatic aphasia, while the use of pitch and amplitude cues is more likely to be preserved in this population. Some, but not all, of these timing differences may be attributable to motor speech programming deficits (AOS) rather than aphasia, as these conditions frequently co-occur. Many of the included studies do not address AOS and its possible role in any observed effects. Finally, the available evidence indicates that even speakers with severe aphasia show a degree of preserved prosody in functional communication.

Frontalis muscle flap eyelid reanimation technique in adults with severe ptosis or apraxia of eyelid opening.

PURPOSE: Assessment of the frontalis muscle flap eyelid reanimation surgical technique for adults with severe ptosis and apraxia of eyelid opening. METHODS: A retrospective case series of 30 eyes with severe ptosis or apraxia of eyelid opening. Outcomes were assessed for margin to reflex distance 1 (MRD1), lagophthalmos, complications, and need for subsequent surgical intervention. A paired t-test was used to compare preoperative and postoperative scores of a quality-of-life questionnaire. RESULTS: Thirty eyes of 19 patients underwent surgery, 16 (53%) with combined frontalis + levator-Muller muscle flap and 14 (46%) with frontalis muscle flap alone. There were 14 female and 5 male patients, with an average age of 55 years (range, 18-76). Mean preoperative MRD1 was -0.6 mm (range, -5 to 2) with mean levator excursion of 7.1 mm. Seventeen eyes had a myogenic etiology, five had a paralytic etiology, six had blepharospasm with apraxia of lid opening, and two had a neurodegenerative etiology. Nineteen eyes (63%) had previously undergone ptosis repair. Mean postoperative MRD1 was 2.5 mm (range, 0.5 to 5) at mean follow-up of 63.3 days. There were no serious surgical complications; minor complications included ocular surface keratopathy and one patient who required surgical revision. Results of the QOL questionnaire indicated significant improvement in vision-related symptoms postoperatively (p = 0.02). CONCLUSIONS: Use of the frontalis muscle flap eyelid reanimation technique, with or without a levator-Muller retractor muscle flap, was very effective in this case series and provided good upper eyelid position with acceptable corneal protection and high patient satisfaction.

Neurological gait assessment.

Gait disorders are a common feature of neurological disease. The gait examination is an essential part of the neurological clinical assessment, providing valuable clues to a myriad of causes. Understanding how to examine gait is not only essential for neurological diagnosis but also for treatment and prognosis. Here, we review aspects of the clinical history and examination of neurological gait to help guide gait disorder assessment. We focus particularly on how to differentiate between common gait abnormalities and highlight the characteristic features of the more prevalent neurological gait patterns such as ataxia, waddling, steppage, spastic gait, Parkinson's disease and functional gait disorders. We also offer diagnostic clues for some unusual gait presentations, such as dystonic, stiff-person and choreiform gait, along with red flags that help differentiate atypical parkinsonism from Parkinson's disease.

The encoding of speech modes in motor speech disorders: whispered versus normal speech in apraxia of speech and hypokinetic dysarthria.

Speakers with motor speech disorders (MSD) present challenges in speech production, one of them being the difficulty to adapt their speech to different modes. However, it is unclear whether different types of MSD are similarly affected when it comes to adapting their speech to various communication contexts. This study investigates the encoding of speech modes in individuals with AoS following focal brain damage and in individuals with hypokinetic dysarthria (HD) secondary to Parkinson's disease. Participants with mild-to-moderate MSD and their age-matched controls performed a delayed production task of pseudo-words in two speech modes: normal and whispered speech. While overall accuracy did not differ significantly across speech modes, participants with AoS exhibited longer response latencies for whispered speech, reflecting difficulties in the initiation of utterances requiring an unvoiced production. In contrast, participants with HD showed faster response latencies for whispered speech, indicating that this speech mode is easier to encode/control for this population. Acoustic durations followed these same trends, with participants with AoS showing greater lengthening for whispered speech as compared to controls and to participants with HD, while participants with HD exhibited milder lengthening. Contrary to the predictions of speech production models, suggesting that speech mode changes might be particularly difficult in dysarthria, the present results suggest that speech mode adaptation rather seems particularly costly for participants with AoS.

Apraxia Patterns for the Differentiation between Alzheimer's Disease and Frontotemporal Dementia Variants.

Background and Objectives: Despite the increasing use of biomarkers, differentiation between Alzheimer's disease (AD), behavioral variant Frontotemporal Dementia (bvFTD), and Primary Progressive Aphasia (PPA) remains a challenge. Apraxia is a supportive feature for diagnosing AD but is underrepresented in other dementia types. Herein, we investigated the presence and characteristic profiles of limb, verbal, and non-verbal apraxia in three major dementia types. Materials and Methods: Test for Upper Limb Apraxia (TULIA) and Apraxia Battery for Adults-2 (ABA-2) were administered in patients with AD (n = 22), bvFTD (n = 41), and PPA (n = 22), with 20 individuals serving as healthy controls (HC). Composite and subdomain scores were compared between each patient group and the HC. Praxis profiles indicative of each dementia type and a possible predictive value were sought. Results: Apraxia provided high diagnostic accuracy for detecting dementia compared with HC (sensitivity: 63.6-100%, specificity: 79.2-100%). Patients with AD performed worse when imitating intransitive gestures as well as pantomiming transitive gestures (mean differences: 2.10 and 3.12, respectively), compared with bvFTD. PPA patients, compared with bvFTD, had comparable results in limb, verbal, and non-verbal praxis assessments, despite the greater deterioration in the outcome. Compared with patients with AD, PPA had increased pathological outcomes in verbal (86.4% vs. 40.9%) and non-verbal apraxia (31.8% vs. 0%), while bvFTD had increased pathological outcomes in verbal apraxia (85.4% vs. 44.5%). Finally, apraxia is correlated with cognitive decline. Conclusions: Apraxia profile evaluation could contribute to the differentiation between AD and Frontotemporal Dementia (FTD). Both TULIA and ABA-2 are reliable tools that can be performed as bed-side tests in clinical practice.

Treatment approaches to Motor Speech Disorders: A step towards Evidence Based Practice.

Motor Speech Disorders is an umbrella term for a set of separate dysfunctions of speech outcome associated with neurological disorders. Motor speech disorders (MSD) are classified as Speech Motor delay (SMD), Childhood dysarthria (CD), Childhood Apraxia of Speech (CAS), and Concurrent CD and CAS. The incidence and prevalence of MSD in population is uncertain. A research gap exists, making evidence-based practice questionable as regards intervention for MSD and is an area of research. Hence, current narrative review was conducted to review and highlight treatment of MSD since evidence-based treatment approach may benefit patient even years after a brain lesion. To achieve this objective literature search was conducted using search engines and data bases including google, google scholar, web of science & PubMed from 1998 to 2023 with keywords "motor speech disorder, dysarthria, apraxia, speech motor delay and combinations of these words with English language and no other limitations. Our search revealed 170 articles, news, publications of which 34 were used for review (Fig.1).

Cognitive Deficits After Stroke.

Cognition is a central feature of human existence and brain function. Cognitive deficits are common after stroke and may strongly impact functional outcome. Recent years have seen substantial advances in our understanding of cognitive functions in the healthy state, and this new body of knowledge promises to open new avenues for understanding and treating poststroke impairments, including cognitive deficits. The 5 reviews in this Focused Update from an international cast of experts provide excellent updates on cognitive syndromes that commonly contribute to poststroke disability: neglect, aphasia, apraxia, loss of executive function, and memory disorders. Cognitive impairment remains a major source of morbidity after stroke; these reviews approach this problem by considering clinical presentations, pathophysiology, measurement tools, and treatment approaches. In doing so, they highlight a number of key questions and critical gaps. A number of issues emerge as common across cognitive domains poststroke and are summarized herein. There is a need for improved methods to measure cognitive impairments, as well as for improved insights into pathophysiology of symptom onset and mechanisms of recovery after stroke, including validated biomarkers. These 5 state of the art summaries are sure to prove useful toward these goals.