-
Cortex; a Journal Devoted To the Study... Sep 2023It has been suggested that Gerstmann's syndrome is the result of subcortical disconnection rather than emerging from damage of a multifunctional brain region within the...
It has been suggested that Gerstmann's syndrome is the result of subcortical disconnection rather than emerging from damage of a multifunctional brain region within the parietal lobe. However, patterns of white matter tract disconnection following parietal damage have been barely investigated. This single case study allows characterising Gerstmann's syndrome in terms of disconnected networks. We report the case of a left parietal patient affected by Gerstmann's tetrad: agraphia, acalculia, left/right orientation problems, and finger agnosia. Lesion mapping, atlas-based estimation of probability of disconnection, and DTI-based tractography revealed that the lesion was mainly located in the superior parietal lobule, and it caused disruption of both intraparietal tracts passing through the inferior parietal lobule (e.g., tracts connecting the angular, supramarginal, postcentral gyri, and the superior parietal lobule) and fronto-parietal long tracts (e.g., the superior longitudinal fasciculus). The lesion site appears to be located more superiorly as compared to the cerebral regions shown active by other studies during tasks impaired in the syndrome, and it reached the subcortical area potentially critical in the emergence of the syndrome, as hypothesised in previous studies. Importantly, the reconstruction of tracts connecting regions within the parietal lobe indicates that this critical subcortical area is mainly crossed by white matter tracts connecting the angular gyrus and the superior parietal lobule. Taken together, these findings suggest that this case study might be considered as empirical evidence of Gerstmann's tetrad caused by disconnection of intraparietal white matter tracts.
Topics: Humans; Gerstmann Syndrome; White Matter; Parietal Lobe; Brain; Agnosia
PubMed: 37478549
DOI: 10.1016/j.cortex.2023.05.016 -
Brain & NeuroRehabilitation Mar 2023Gerstmann syndrome (GS) is a rare syndrome that occurs when there is a lesion of the dominant inferior parietal lobule (IPL), causing agraphia, acalculia, finger...
Gerstmann syndrome (GS) is a rare syndrome that occurs when there is a lesion of the dominant inferior parietal lobule (IPL), causing agraphia, acalculia, finger agnosia, and right-left disorientation. A 49-year-old right-handed male was diagnosed as GS after left parieto-occipital lobe hemorrhage. The patient showed mild anomic aphasia with agraphia in the language test and the neuropsychological test revealed acalculia, impaired right-left discrimination, and finger agnosia. In diffusion tensor tractography, the tracts of left superior longitudinal fasciculus (SLF), middle longitudinal fasciculus, U-fibers and posterior corpus callosum (CC) were disrupted around the left IPL. In addition, fractional anisotropy (FA) values were markedly decreased in left SLF, and posterior CC when compared to twelve healthy control subjects. Our clinical and neuroimaging findings support that GS is a disconnection syndrome caused by lesion in the white matter pathway surrounding IPL. In future, more studies of the correlation between the white matter disconnection and the development of GS including high quality imaging technique are needed.
PubMed: 37033002
DOI: 10.12786/bn.2023.16.e3 -
Scientific Reports Feb 2020This paper proposes new ways to assess handwriting, a critical skill in any child's school journey. Traditionally, a pen and paper test called the BHK test (Concise...
This paper proposes new ways to assess handwriting, a critical skill in any child's school journey. Traditionally, a pen and paper test called the BHK test (Concise Evaluation Scale for Children's Handwriting) is used to assess children's handwriting in French-speaking countries. Any child with a BHK score above a certain threshold is diagnosed as 'dysgraphic', meaning that they are then eligible for financial coverage for therapeutic support. We previously developed a version of the BHK for tablet computers which provides rich data on the dynamics of writing (acceleration, pressure, and so forth). The underlying model was trained on dysgraphic and non-dysgraphic children. In this contribution, we deviate from the original BHK for three reasons. First, in this instance, we are interested not in a binary output but rather a scale of handwriting difficulties, from the lightest cases to the most severe. Therefore, we wish to compute how far a child's score is from the average score of children of the same age and gender. Second, our model analyses dynamic features that are not accessible on paper; hence, the BHK is useful in this instance. Using the PCA (Principal Component Analysis) reduced the set of 53 handwriting features to three dimensions that are independent of the BHK. Nonetheless, we double-checked that, when clustering our data set along any of these three axes, we accurately detected dysgraphic children. Third, dysgraphia is an umbrella concept that embraces a broad variety of handwriting difficulties. Two children with the same global score can have totally different types of handwriting difficulties. For instance, one child could apply uneven pen pressure while another one could have trouble controlling their writing speed. Our new test not only provides a global score, but it also includes four specific score for kinematics, pressure, pen tilt and static features (letter shape). Replacing a global score with a more detailed profile enables the selection of remediation games that are very specific to each profile.
Topics: Agraphia; Algorithms; Biomechanical Phenomena; Child; Child, Preschool; Cluster Analysis; Female; Handwriting; Humans; Machine Learning; Male; Motor Skills; Pattern Recognition, Automated; Principal Component Analysis; Psychomotor Performance
PubMed: 32081940
DOI: 10.1038/s41598-020-60011-8 -
Journal of Postgraduate Medicine 2021Agraphia is defined as the disruption of the previously intact writing skills due to an acquired brain damage. Stroke remains the most common cause of language...
Agraphia is defined as the disruption of the previously intact writing skills due to an acquired brain damage. Stroke remains the most common cause of language impairment; however, writing disorders, including agraphia, are underestimated in patients with stroke. In this regard, we report two patients presenting with pure agraphia as an early symptom of stroke. Both patients complained of at least two difficulties in visualizing letter formation beforehand, the frequent need for verbal cues, misuse of lines and margins, poorly legible signature, and writing and thinking at the same time (e.g., creative thinking and taking notes). They underwent brain magnetic resonance imaging which revealed a small lacunar infarction of the left insula and external capsule (patient 1) and a small hemorrhagic lesion in the posterior limb of the left internal capsule (patient 2). To our knowledge, this is the first report on pure agraphia as the presenting symptom of stroke. We suggest that all patients with acute agraphia, even when presenting as an isolated symptom, should be evaluated for stroke, in order to better facilitate its diagnosis and treatment.
Topics: Agraphia; Brain; External Capsule; Humans; Internal Capsule; Magnetic Resonance Imaging; Male; Middle Aged; Stroke; Stroke, Lacunar
PubMed: 33835058
DOI: 10.4103/jpgm.JPGM_1066_20 -
Journal of Neurovirology Oct 2023Intensive immunosuppression has enabled liver transplantation even in recipients with preformed donor-specific antibodies (DSA), an independent risk factor for graft...
Intensive immunosuppression has enabled liver transplantation even in recipients with preformed donor-specific antibodies (DSA), an independent risk factor for graft rejection. However, these recipients may also be at high risk of progressive multifocal encephalopathy (PML) due to the comorbid immunosuppressed status. A 58-year-old woman presented with self-limited focal-to-bilateral tonic-clonic seizures 9 months after liver transplantation. She was desensitized using rituximab and plasma exchange before transplantation and was subsequently treated with steroids, tacrolimus, and everolimus after transplantation for her preformed DSA. Neurological examination revealed mild acalculia and agraphia. Cranial MRI showed asymmetric, cortex-sparing white matter lesions that increased over a week in the left frontal, left parietal, and right parieto-occipital lobes. Polymerase chain reaction (PCR) of the cerebrospinal fluid for the JC supported the diagnosis of PML. Immune reconstitution by reducing the immunosuppressant dose stopped lesion expansion, and PCR of the cerebrospinal fluid for the JC virus became negative. Graft rejection occurred 2 months after immune reconstitution, requiring readjustment of immunosuppressants. Forty-eight months after PML onset, the patient lived at home without disabling deficits. Intensive immunosuppression may predispose recipients to PML after liver transplantation with preformed DSA. Early immune reconstitution and careful monitoring of graft rejection may help improve outcomes.
Topics: Humans; Female; Middle Aged; Leukoencephalopathy, Progressive Multifocal; Liver Transplantation; Living Donors; JC Virus; Immunosuppressive Agents
PubMed: 37668873
DOI: 10.1007/s13365-023-01171-x -
Cortex; a Journal Devoted To the Study... Oct 2020This study, through a series of univariate and multivariate (classification) analyses, investigated fMRI task-based functional connectivity (FC) at pre- and...
This study, through a series of univariate and multivariate (classification) analyses, investigated fMRI task-based functional connectivity (FC) at pre- and post-treatment time-points in 18 individuals with chronic post-stroke dysgraphia. The investigation examined the effects of lesion and treatment-based recovery on functional organization, focusing on both inter-hemispheric (homotopic) and intra-hemispheric connectivity. The work confirmed, in the chronic stage, the "network phenotype of stroke injury" proposed by Siegel et al. (2016) consisting of abnormally low inter-hemispheric connectivity as well as abnormally high intra-hemispheric (ipsilesional) connectivity. In terms of recovery-based changes in FC, this study found overall hyper-normalization of these abnormal inter and intra-hemispheric connectivity patterns, suggestive of over-correction. Specifically, treatment-related homotopic FC increases were observed between left and right dorsal frontal-parietal regions. With regard to intra-hemispheric connections, recovery was dominated by increased ipsilateral connectivity between frontal and parietal regions along with decreased connectivity between the frontal regions and posterior parietal-occipital-temporal areas. Both inter and intra-hemispheric changes were associated with treatment-driven improvements in spelling performance. We suggest an interpretation according to which, with treatment, as posterior orthographic processing areas become more effective, executive control from frontal-parietal networks becomes less necessary.
Topics: Brain; Brain Mapping; Humans; Magnetic Resonance Imaging; Phenotype; Stroke
PubMed: 32781259
DOI: 10.1016/j.cortex.2020.06.011 -
Neurological Sciences : Official... Apr 2024Corticobasal syndrome (CBS) is typically asymmetric. Case reports suggest that left-hemisphere CBS (lhCBS) is associated with major language impairment, and...
BACKGROUND
Corticobasal syndrome (CBS) is typically asymmetric. Case reports suggest that left-hemisphere CBS (lhCBS) is associated with major language impairment, and right-hemisphere CBS (rhCBS) is associated with major visuospatial deficits, but no group study has ever verified these observations. In our study, we enrolled 49 patients with CBS, classified them as lhCBS or rhCBS based on asymmetry of hypometabolism on brain FDG-PET and compared their cognitive and behavioural profiles.
METHODS
We defined asymmetry of hypometabolism upon visual inspection of qualitative PET images and confirmed it through paired comparison of left- and right-hemisphere FDG uptake values. The two groups were also matched for severity of hypometabolism within the more affected and more preserved hemispheres, to unravel differences in the cognitive profiles ascribable specifically to each hemisphere's functional specializations. All patients were assessed for memory, language, executive and visuospatial deficits, apraxia, neglect, dyscalculia, agraphia and behavioural disturbances.
RESULTS
LhCBS (n. 26) and rhCBS (n. 23) patients did not differ for demographics, disease duration and severity of global cognitive impairment. The two cognitive profiles were largely overlapping, with two exceptions: Digit span forward was poorer in lhCBS, and visual neglect was more frequent in rhCBS.
CONCLUSIONS
After balancing out patients for hemispheric hypometabolism, we did not confirm worse language or visuospatial deficits in, respectively, lhCBS and rhCBS. However, verbal short-term memory was more impaired in lhCBS, and spatial attention was more impaired in rhCBS. Both of these functions reflect the functional specialization of the left and right fronto-parietal pathways, i.e. of the main loci of neurodegeneration in CBS.
Topics: Humans; Fluorodeoxyglucose F18; Corticobasal Degeneration; Research Design; Brain; Positron-Emission Tomography; Cognition
PubMed: 37889380
DOI: 10.1007/s10072-023-07148-2 -
NeuroImage Nov 2019Identifying the neural changes that support recovery of cognitive functions after a brain lesion is important to advance our understanding of human neuroplasticity,...
Identifying the neural changes that support recovery of cognitive functions after a brain lesion is important to advance our understanding of human neuroplasticity, which, in turn, forms the basis for the development of effective treatments. To date, the preponderance of neuroimaging studies has focused on localizing changes in average brain activity associated with functional recovery. Here, we took a novel approach by evaluating whether cognitive recovery in chronic stroke is related to increases in the differentiation of local neural response patterns. This approach is supported by research indicating that, in the intact brain, local neural representations become more differentiated (dissimilar) with learning (Glezer et al., 2015). We acquired fMRI data before and after 21 individuals received approximately 12 weeks of behavioral treatment for written language impairment due to a left-hemisphere stroke. We used Local-Heterogeneity Regression Analysis (Purcell and Rapp, 2018) to measure local neural response differentiation associated with written language processing, assuming that greater heterogeneity in the pattern of activity across adjacent neural areas indicates more well-differentiated neural representations. First, we observed pre to post-treatment increases in local neural differentiation (Local-Hreg) in the ventral occipital-temporal cortex of the left hemisphere. Second, we found that, in this region, higher local neural response differentiation prior to treatment was associated with less severe written language impairment, and that it also predicted greater future responsiveness to treatment. Third, we observed that changes in neural differentiation were systematically related to performance changes for trained and untrained items. Fourth, we did not observe these brain-behavior relationships for mean BOLD responses, only for Local-Hreg. Thus, this is the first investigation to quantify changes in local neural differentiation in the recovery of a cognitive function and the first to demonstrate the clear behavioral relevance of these changes. We conclude that the findings provide strong support for the novel hypothesis that the local re-differentiation of neural representations can play a significant role in functional recovery after brain lesion.
Topics: Aged; Aged, 80 and over; Agraphia; Brain; Brain Mapping; Female; Humans; Learning; Magnetic Resonance Imaging; Male; Middle Aged; Pattern Recognition, Visual; Recovery of Function; Speech Perception; Stroke
PubMed: 31479754
DOI: 10.1016/j.neuroimage.2019.116145 -
Open Forum Infectious Diseases Mar 2023We present the case of a 61-year-old woman with a history of orthotopic heart transplant who was hospitalized with new-onset headache. Magnetic resonance imaging (MRI)...
We present the case of a 61-year-old woman with a history of orthotopic heart transplant who was hospitalized with new-onset headache. Magnetic resonance imaging (MRI) of the brain revealed T2 hyperintense signal involving the left occipital lobe with leptomeningeal enhancement and mild vasogenic edema. Initial neurologic examination was normal; however, after 7 days she developed imbalance, visual disturbances, night sweats, bradyphrenia, alexia without agraphia, and right hemianopsia. Brain MRI showed enlargement of the left occipital mass and worsening edema. Stereotactic needle biopsy showed nondiagnostic necrosis. The patient continued to deteriorate despite dexamethasone. Cerebrospinal fluid (CSF) suggested infection, and cytomegalovirus CSF polymerase chain reaction (PCR) was positive. The patient received vancomycin, imipenem, and ganciclovir. After obtaining a positive serum beta-D-glucan (Fungitell), amphotericin was added. Despite best medical efforts, the patient died. Postmortem broad-range PCR sequencing of the brain tissue was positive for rare amoeba .
PubMed: 37008568
DOI: 10.1093/ofid/ofad094 -
Case Reports in Psychiatry 2022We report the case of an 8-year-old child with a complex neurodevelopmental disorder, including severe developmental coordination disorder with dysgraphia, anxiety and...
We report the case of an 8-year-old child with a complex neurodevelopmental disorder, including severe developmental coordination disorder with dysgraphia, anxiety and depression, mild social functioning impairments, headache and chronic musculoskeletal pain, secondary to Ehlers-Danlos syndrome (EDS) hypermobility type. We explored whether wearing whole-body compressive garments (CGs) could improve his motor skills assessed through standardized and experimental procedures. In addition to the effectiveness of CGs on pain, we found partial improvements in his motor skills, specifically postural control, hand movements, and body schema representation, after wearing CGs for 15 days. During an experimental motor imitation task with a virtual tightrope walker, we found improvements in interpersonal synchronization with performances closer to those of typical developing (TD) controls. We conclude that CGs appear to be an innovative and interesting adjuvant treatment for motor skill impairments in children with multidimensional impairments involving EDS. These promising results require confirmation by further evidence-based research.
PubMed: 36111244
DOI: 10.1155/2022/5819406