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.

Collet-Sicard syndrome due to cervical artery dissection disclosed by high-resolution magnetic resonance imaging.

BACKGROUND AND PURPOSE: Cervical artery dissection (CAD) represents a leading cause of unilateral lower cranial nerve IX-XII palsy, known as Collet-Sicard syndrome (CSS). High-resolution magnetic resonance imaging (HR-MRI) is widely used in the evaluation of patients with CAD, providing information regarding vessel wall abnormalities and intraluminal thrombus. METHODS: We present a patient with palsy of multiple lower cranial nerves in the context of CSS, attributed to unilateral spontaneous internal carotid artery dissection. RESULTS: We describe a 68-year-old man with unremarkable previous history, who presented with subacute, gradually worsening dysphagia and hoarse voice. Clinical examination revealed right-sided palsy of cranial nerves IX-XII. Three-dimensional fat-saturated black-blood T1-weighted high-resolution vessel wall imaging disclosed spontaneous dissection with intramural hematoma along the distal right internal carotid artery. Neck MRI showed inward displacement of right aryepiglottic fold, right pyriform sinus dilatation, and right true vocal cord in middle position, indicative of right vagus nerve palsy, atrophy of right trapezius and sternocleidomastoid muscles, due to right spinal accessory nerve palsy, and unilateral tongue atrophy with fatty infiltration, characteristic for right hypoglossal nerve palsy. CONCLUSIONS: This case highlights the utility of high-resolution vessel wall imaging and especially fat-saturated T1-weighted black-blood SPACE (sampling perfection with application-optimized contrast using different flip-angle evolutions) sequences in the accurate diagnosis of CAD, revealing the characteristic mural hematoma and intimal flap. HR-MRI is also valuable in the recognition of indirect signs of lower cranial nerve compression.

Hypoperfusion index ratio and pretreatment with intravenous thrombolysis are independent predictors of good functional outcome in acute ischemic stroke patients with large vessel occlusion treated with acute reperfusion therapies.

INTRODUCTION: We aimed to investigate the performance of several neuroimaging markers provided by perfusion imaging of Acute Ischemic Stroke (AIS) patients with large vessel occlusion (LVO) in order to predict clinical outcomes following reperfusion treatments. METHODS: We prospectively evaluated consecutive AIS patients with LVO who were treated with reperfusion therapies, during a six-year period. In order to compare patients with good (mRS scores 0-2) and poor (mRS scores 3-6) functional outcomes, data regarding clinical characteristics, the Alberta Stroke Programme Early Computed Tomography Score (ASPECTS) based on unenhanced computed tomography (CT), CT angiography collateral status and perfusion parameters including ischemic core, hypoperfusion volume, mismatch volume between core and penumbra, Tmax > 10 s volume, CBV index and the Hypoperfusion Index Ratio (HIR) were assessed. RESULTS: A total of 84 acute stroke patients with LVO who met all the inclusion criteria were enrolled. In multivariable logistic regression models increasing age (odds ratio [OR]: 0.93; 95%CI: 0.88-0.96, p = 0.001), lower admission National Institute of Health Stroke Scale (NIHSS)-score (OR: 0.88; 95%CI: 0.80-0.95, p = 0.004), pretreatment with intravenous thrombolysis (OR: 3.83; 95%CI: 1.29-12.49, p = 0.019) and HIR (OR:0.36; 95%CI: 0.10-0.95, p = 0.042) were independent predictors of good functional outcome at 3 months. The initial univariable associations between HIR and higher likelihood for symptomatic intracranial hemorrhage (sICH) and parenchymal hematoma type 2 (PH2) were attenuated in multivariable analyses failing to reach statistical significance. DISCUSSION: Our pilot observational study of unselected AIS patients with LVO treated with reperfusion therapies demonstrated that pre-treatment low HIR in perfusion imaging and IVT were associated with better functional outcomes.

Challenges in diagnosis and management of cerebral venous thrombosis as underlying cause of lobar intracerebral hemorrhage.

OBJECTIVES: Cerebral venous thrombosis is an uncommon, yet life-threatening condition, affecting mainly young and middle-aged individuals. Moreover, it represents an underrecognised etiology of lobar intracerebral hemorrhage (ICH). The clinical course of CVT is variable in the first days after diagnosis and medical complications including pulmonary embolism (PE) may result in early neurological deterioration and death if left untreated. MATERIALS AND METHODS: Case report. RESULTS: We describe a 46-year-old man with acute left hemiparesis and dysarthria in the context of lobar ICH due to underlying CVT of Trolard vein. Diagnosis was delayed because of misinterpretation of the initial neuroimaging study. Subsequently, the patient rapidly deteriorated and developed submassive PE and left iliofemoral venous thrombosis in the setting of previously undiagnosed hereditary thrombophilia (heterozygous prothrombin gene mutation G2021A). Emergent aspiration thrombectomy was performed resulting in the successful management of PE. A follow-up MRI study confirmed the thrombosed Trolard vein, thus establishing the CVT diagnosis. Anticoagulation treatment was immediately escalated to enoxaparine therapeutic dose resulting in clinical improvement of neurological deficits. CONCLUSIONS: Delayed diagnosis of cerebral venous thrombosis with underlying causes of lobar ICH may result in dire complications. Swift initiation of anticoagulants is paramount even in patients with lobar intracerebral hemorrhage as the initial manifestation of cerebral venous thrombosis.

Pearls & Oy-sters: Thyroid-Associated Ophthalmopathy and Transient Neuromuscular Junction Disorder Due to Graves Disease.

The concomitant presentation of thyroid-associated ophthalmopathy (TAO) and ocular myasthenia gravis is well documented. In the course of Graves disease (GD), symptomatic transient neuromuscular junction disorder may occur due to the effect of thyroid hormones at the neuromuscular synapse. Diagnostic clues are the clinical and electrophysiologic remission synchronous with restoration of euthyroidism. Furthermore, the occurrence of thymic hyperplasia in GD poses further diagnostic and therapeutic considerations. These points are discussed in the case report of a 43-year-old male patient suffering from TAO and transient neuromuscular junction disorder due to GD.

A Magnetic Resonance Spectroscopy Study on Polarity Subphenotypes in Bipolar Disorder.

Although magnetic resonance spectroscopy (MRS) has provided in vivo measurements of brain chemical profiles in bipolar disorder (BD), there are no data on clinically and therapeutically important onset polarity (OP) and predominant polarity (PP). We conducted a proton MRS study in BD polarity subphenotypes, focusing on emotion regulation brain regions. Forty-one euthymic BD patients stratified according to OP and PP and sixteen healthy controls (HC) were compared. 1H-MRS spectra of the anterior and posterior cingulate cortex (ACC, PCC), left and right hippocampus (LHIPPO, RHIPPO) were acquired at 3.0T to determine metabolite concentrations. We found significant main effects of OP in ACC mI, mI/tNAA, mI/tCr, mI/tCho, PCC tCho, and RHIPPO tNAA/tCho and tCho/tCr. Although PP had no significant main effects, several medium and large effect sizes emerged. Compared to HC, manic subphenotypes (i.e., manic-OP, manic-PP) showed greater differences in RHIPPO and PCC, whereas depressive suphenotypes (i.e., depressive-OP, depressive-PP) in ACC. Effect sizes were consistent between OP and PP as high intraclass correlation coefficients (ICC) were confirmed. Our findings support the utility of MRS in the study of the neurobiological underpinnings of OP and PP, highlighting that the regional specificity of metabolite changes within the emotion regulation network consistently marks both polarity subphenotypes.

Tenecteplase for the treatment of acute ischemic stroke in the extended time window: a systematic review and meta-analysis.

Background: Outcome data regarding the administration of tenecteplase (TNK) to acute ischemic stroke (AIS) patients presenting in the extended time window are limited. Objectives: We aimed to assess the current evidence regarding the efficacy and safety of TNK at a dose of 0.25 mg/kg for AIS treatment in the extended time window. Design: A systematic review and meta-analysis was conducted including all available randomized-controlled clinical trials (RCTs) that compared TNK 0.25 mg/kg versus no thrombolysis in AIS patients presenting in the extended time window (>4.5 h after last-seen-well or witnessed onset). Data sources and methods: Eligible studies were identified by searching Medline, Scopus, and international conference abstracts. The predefined efficacy outcomes of interest were 3-month excellent functional outcome [defined as the modified Rankin Scale (mRS) score ⩽1; primary outcome], 3-month good functional outcome (mRS ⩽ 2), 3-month reduced disability (⩾1-point reduction across all mRS scores). We determined symptomatic intracranial hemorrhage (sICH), any ICH and 3-month mortality as safety endpoints. A random-effects model was used to calculate risk ratios (RRs) and common odds ratios (cORs) with corresponding 95% confidence intervals (CIs). Results: Three RCTs were included comprising 556 patients treated with TNK versus 560 controls. TNK 0.25 mg/kg was associated with a higher likelihood of 3-month excellent functional outcome compared to controls (RR = 1.17; 95% CI = 1.01-1.36; I2 = 0%), whereas there was no difference regarding good functional outcome (RR = 1.05; 95% CI = 0.94-1.17; I2 = 0%) and reduced disability (adjusted cOR = 1.14; 95% CI = 0.92-1.40; I2 = 0%) at 3 months. The risks of sICH (RR = 1.67; 95% CI = 0.70-4.00; I2 = 0%), any ICH (RR = 1.08; 95% CI = 0.90-1.29; I2 = 0%) and 3-month mortality (RR = 1.10; 95% CI = 0.81-1.49; I2 = 0%) were similar between the groups. Conclusion: Based on data from three RCTs showing increased efficacy and a favorable safety profile of TNK in the treatment of AIS in the extended time window, continuing efforts of ongoing RCTs in the field are clearly supported. Trial registration: PROSPERO registration ID: CRD42023448707.

Brain multi-contrast, multi-atlas segmentation of diffusion tensor imaging and ensemble learning automatically diagnose late-life depression.

We investigated the potential of machine learning for diagnostic classification in late-life major depression based on an advanced whole brain white matter segmentation framework. Twenty-six late-life depression and 12 never depressed individuals aged > 55 years, matched for age, MMSE, and education underwent brain diffusion tensor imaging and a multi-contrast, multi-atlas segmentation in MRIcloud. Fractional anisotropy volume, mean fractional anisotropy, trace, axial and radial diffusivity (RD) extracted from 146 white matter parcels for each subject were used to train and test the AdaBoost classifier using stratified 12-fold cross validation. Performance was evaluated using various measures. The statistical power of the classifier was assessed using label permutation test. Statistical analysis did not yield significant differences in DTI measures between the groups. The classifier achieved a balanced accuracy of 71% and an Area Under the Receiver Operator Characteristic Curve (ROC-AUC) of 0.81 by trace, and a balanced accuracy of 70% and a ROC-AUC of 0.80 by RD, in limbic, cortico-basal ganglia-thalamo-cortical loop, brainstem, external and internal capsules, callosal and cerebellar structures. Both indices shared important structures for classification, while fornix was the most important structure for classification by both indices. The classifier proved statistically significant, as trace and RD ROC-AUC scores after permutation were lower than those obtained with the actual data (P = 0.022 and P = 0.024, respectively). Similar results were obtained with the Gradient Boosting classifier, whereas the RBF-kernel Support Vector Machine with k-best feature selection did not exceed the chance level. Finally, AdaBoost significantly predicted the class using all features together. Limitations are discussed. The results encourage further investigation of the implemented methods for computer aided diagnostics and anatomically informed therapeutics.

Investigating Aphasia Recovery: Demographic and Clinical Factors.

Post-stroke language recovery remains one of the main unresolved topics in the field of aphasia. In recent years, there have been efforts to identify specific factors that could potentially lead to improved language recovery. However, the exact relationship between the recovery of particular language functions and possible predictors, such as demographic or lesion variables, is yet to be fully understood. In the present study, we attempted to investigate such relationships in 42 patients with aphasia after left hemisphere stroke, focusing on three language domains: auditory comprehension, naming and speech fluency. Structural imaging data were also obtained for the identification of the lesion sites. According to our findings, patients demonstrated an overall improvement in all three language domains, while no demographic factor significantly contributed to aphasia recovery. Interestingly, specific lesion loci seemed to have a differential effect on language performance, depending on the time of testing (i.e., acute/subacute vs. chronic phase). We argue that this variability concerning lesion-deficit associations reflects the dynamic nature of aphasia and further discuss possible explanations in the framework of neuroplastic changes during aphasia recovery.