Evolution of Neuropsychological Deficits in First-Ever Isolated Ischemic Thalamic Stroke and Their Association With Stroke Topography: A Case-Control Study.

BACKGROUND The thalamus plays an essential role in cognition. Cognitive deficits have to date mostly been studied retrospectively in chronic thalamic stroke in small cohorts. Studies prospectively evaluating the evolution of cognitive deficits and their association with thalamic stroke topography are lacking. This knowledge is relevant for targeted patient diagnostics and rehabilitation. METHODS Thirty-seven patients (57.5±17.5 [mean±SD] years, 57% men) with first-ever acute isolated ischemic stroke covering the anterior (n=5), paramedian (n=12), or inferolateral (n=20) thalamus and 37 in-patient controls without stroke with similar vascular risk factors matched for age and sex were prospectively studied. Cognition was evaluated using predefined tests at 1, 6, 12, and 24 months. Voxel-based lesion-symptom mapping was used to determine associations between neuropsychological deficits and stroke topography. RESULTS Patients with anterior thalamic stroke revealed severe deficits in verbal memory (median T score [Q1-Q3]: 39.1 [36.1-44.1]), language (31.8 [31.0-43.8]), and executive functions (43.8 [35.5-48.1]) at 1 month compared with controls (verbal memory: 48.5 [43.6-61.0], language: 55.7 [42.3-61.1], executive functions: 51.3 [50.1-56.8]). Patients with paramedian thalamic stroke showed moderate language (44.7 [42.8-55.9]) and executive (49.5 [44.3-55.1]) deficits and no verbal memory deficits (48.1 [42.5-54.7]) at 1 month compared with controls (59.0 [47.0-64.5]; 59.6 [51.1-61.3]; 52.5 [44.2-55.3]). The language and executive deficits in paramedian thalamic stroke patients almost completely recovered during follow-up. Intriguingly, significant deficits in verbal memory (44.7 [41.5-51.9]), language (47.5 [41.8-54.1]), and executive functions (48.2 [46.2-59.7]) were found in inferolateral thalamic stroke patients at 1 month compared with controls (50.5 [46.7-59.9]; 57.0 [51.2-62.9]; 57.4 [51.2-60.7]). Language, but not executive deficits persisted during follow-up. Voxel-based lesion-symptom mapping revealed an association of verbal memory deficits with anterior thalamus lesions and an association of non-verbal memory, language, and executive deficits with lesions at the anterior/paramedian/inferolateral border. CONCLUSIONS All 3 stroke topographies exhibited significant deficits in diverse cognitive domains, which recovered to a different degree depending on the stroke localization. Our study emphasizes the need for comprehensive neuropsychological diagnostics to secure adequate patient rehabilitation

Depression and anxiety in acute ischemic stroke involving the anterior but not paramedian or inferolateral thalamus

Background and objectivesEmotional and cognitive deficits are prevalent in strokes involving the thalamus. In contrast to cognitive deficits, emotional deficits have not been studied prospectively in isolated thalamic stroke.MethodsIn 37 ischemic thalamic stroke patients (57.0 [50.0; 69.5] years [median (Q1; Q3)], 21 males, 5 anterior, 12 paramedian, 20 inferolateral vascular territory), and 37 non-stroke control patients matched for age and sex, we prospectively examined depression, anxiety, activities of daily living, and quality of life at 1, 6, 12, and 24 months post-stroke using the Hospital-Anxiety-and-Depression Scale (HADS), Nürnberger-Alters-Alltagsaktivitäten scale (NAA), and Short Form-36 (SF36) questionnaire. Voxel-based lesion-symptom mapping (VLSM) and lesion-subtraction analyzes were performed to determine associations between questionnaire scores and thalamic stroke topography.ResultsAt 1 month post-stroke, anterior thalamic stroke patients had higher depression scores [8.0 (7.5; 10.5)] than paramedian [4.5 (1.0; 5.8)] and inferolateral [4.0 (1.0; 7.0)] thalamic stroke patients. Furthermore, anterior thalamic stroke patients had higher anxiety scores [11.0 (8.0; 14.5)] than their matched controls [2.5 (2.0; 2.5)], paramedian [4.5 (1.0; 5.8)] and inferior [4.0 (1.0; 7.0)] thalamic stroke patients. Depression and anxiety scores in anterior thalamic stroke patients remained high across the follow-up [depression: 9.0 (3.5; 13,8); anxiety:10.05 (2.8, 14.5)].Physical health assessed by SF36 was intact in anterior [1 month post-stroke: T-score = 55.9 (37.0; 57.6)] but reduced in inferolateral [44.5(32.4; 53.1)] thalamic stroke, whereas mental health was reduced in anterior thalamic stroke [32.0 (29.8; 47.3)].VLSM confirmed that voxels in the anterior thalamus around Montreal Neurological Institute (MNI) coordinates X = −8, Y = −12, Z = 2 were more often affected by the stroke in depressed (HADS-score ≥ 8) than non-depressed (HADS-score < 8) patients and voxels around coordinates X = −10, Y = −12, Z = 2 were more often affected in anxious (HADS-score ≥ 8) than non-anxious (HADS-score < 8) patients.ConclusionAnterior, but not paramedian or inferolateral thalamic stroke was associated with depression and anxiety. Even though our results are mostly significant in the left thalamus, this observation on stroke laterality might be confounded by the fact that the right hemisphere was underrepresented in our study

Low-Dose High-Resolution Photon-Counting CT of the Lung: Radiation Dose and Image Quality in the Clinical Routine

This study aims to investigate the qualitative and quantitative image quality of low-dose high-resolution (LD-HR) lung CT scans acquired with the first clinical approved photon counting CT (PCCT) scanner. Furthermore, the radiation dose used by the PCCT is compared to a conventional CT scanner with an energy-integrating detector system (EID-CT). Twenty-nine patients who underwent a LD-HR chest CT scan with dual-source PCCT and had previously undergone a LD-HR chest CT with a standard EID-CT scanner were retrospectively included in this study. Images of the whole lung as well as enlarged image sections displaying a specific finding (lesion) were evaluated in terms of overall image quality, image sharpness and image noise by three senior radiologists using a 5-point Likert scale. The PCCT images were reconstructed with and without a quantum iterative reconstruction algorithm (PCCT QIR+/−). Noise and signal-to-noise (SNR) were measured and the effective radiation dose was calculated. Overall, image quality and image sharpness were rated best in PCCT (QIR+) images. A significant difference was seen particularly in image sections of PCCT (QIR+) images compared to EID-CT images (p < 0.005). Image noise of PCCT (QIR+) images was significantly lower compared to EID-CT images in image sections (p = 0.005). In contrast, noise was lowest on EID-CT images (p < 0.001). The PCCT used significantly less radiation dose compared to the EID-CT (p < 0.001). In conclusion, LD-HR PCCT scans of the lung provide better image quality while using significantly less radiation dose compared to EID-CT scans

Safety and Efficacy of the Novel Low-Profile APERIO Hybrid17 for a Treatment of Proximal and Distal Vessel Occlusion in Acute Ischemic Stroke: A Multi-Center Experience

OBJECTIVE: To report our initial experience with the novel low-profile APERIO Hybrid17 Thrombectomy Device (AP17) for proximal and distal vessel occlusions in acute ischemic stroke.METHODS: A multicentric retrospective analysis of pa-tients treated with the AP17 was performed. The primary effectiveness endpoint was first-pass TICI >= 2b (Thrombol-ysis in cerebral infarction scale). The primary safety endpoint was the occurrence of hemorrhagic complications. Further outcome measures were number of passes, device -related complications, and 3-month functional outcome.RESULTS: The AP17 was used in 71 patients (mean age: 73 years) with a median baseline National Institutes of Health Stroke Scale score of 9. Treated vessels were the carotid-T in 8 cases (11%), the M1-segment in 16 (23%), the M2-segment in 29 (41%), the anterior cerebral artery in 3 (4%), and basilar/posterior cerebral arteries in 15 (21%). The rates of first-pass and final TICI >= 2b were 75.6% and 92.7%, retrospectively, with a mean number of passes of 3 +/- 2. Final TICI >= 2b rates were comparable between large and medium vessel occlusions. Symptomatic intracranial hemorrhages were recorded in 2 cases (2.8%). At 3-month clinical follow-up, a modified Rankin scale score 2 pound was achieved in 69.0% (29/42). The all-cause mortality at discharge was 17.4%.CONCLUSIONS: The AP17 was associated with a reasonable safety and efficacy profile for both proximal and distal vessel occlusions. These results may contribute to establish mechanical thrombectomy for distal occlusions

Photon Counting CT Angiography of the Head and Neck: Image Quality Assessment of Polyenergetic and Virtual Monoenergetic Reconstructions

Background: The purpose of the present study was the evaluation of the image quality of polyenergetic and monoenergetic reconstructions (PERs and MERs) of CT angiographies (CTAs) of the head and neck acquired with the novel photon counting CT (PCCT) method in clinical routine. Methods: Thirty-seven patients were enrolled in this retrospective study. Quantitative image parameters of the extracranial, intracranial and cerebral arteries were evaluated for the PER and MER (40–120 keV). Additionally, two radiologists rated the perceived image quality. Results: The mean CTDIvol used in the PCCT was 8.31 ± 1.19 mGy. The highest signal within the vessels was detected in the 40 keV MER, whereas the lowest noise was detected in the 115 keV MER. The most favorable contrast-to-noise-ratio (CNR) and signal-to-noise-ratio (SNR) were detected in the PER and low keV MER. In the qualitative image analysis, the PER was superior to the MER in all rated criteria. For MER, 60–65 keV was rated as best image quality. Conclusion: Overall, PCCT offers excellent image quality for CTAs of the head and neck. At the current state, the PER of the PCCT seems to be the most favorable reconstruction for diagnostic reporting

Automatic determination of white matter hyperintensity properties in relation to the development of Alzheimer's disease

Alzheimer's disease (AD) is the most common form of dementia seen in the elderly. No curing medicine for AD exists at this moment. In the search for an effective medicine, research is directed towards the prediction of conversion of mild cognitive impairment (MCI) to AD. White matter hyperintensities (WMHs) have been shown to contain information regarding the development of AD, although non-conclusive results are found in literature. These studies often use qualitative measures to describe WMHs, which is time consuming and prone to variability. To investigate the relation between WMHs and the development of AD, algorithms to automatically determine quantitative properties in terms of volume and spatial distribution of WMHs are developed and compared between normal controls and MCI subjects. MCI subjects have a significantly higher total volume of WMHs than normal controls. This difference persists when lesions are classified according to their distance to the ventricular wall. Spatial distribution is also described by defining different brain regions based on a common coordinate system. This reveals that MCI subjects have a larger WMH volume in the upper part of the brain compared to normal controls. In four subjects, the change of WMH properties over time is studied in detail. Although such a small dataset cannot be used to give definitive conclusions, the data suggests that progression of WMHs in subjects with a low lesion load is caused by an increase in the number of lesions and by the progression of juxtacortical lesions. In subjects with a larger lesion load, progression is caused by expansion of pre-existing lesions

Diffuse Axonal Injury at Ultra-High Field MRI

<div><p>Objective</p><p>Diffuse axonal injury (DAI) is a specific type of traumatic brain injury caused by shearing forces leading to widespread tearing of axons and small vessels. Traumatic microbleeds (TMBs) are regarded as a radiological marker for DAI. This study aims to compare DAI-associated TMBs at 3 Tesla (T) and 7 T susceptibility weighted imaging (SWI) to evaluate possible diagnostic benefits of ultra-high field (UHF) MRI.</p><p>Material and Methods</p><p>10 study participants (4 male, 6 female, age range 20-74 years) with known DAI were included. All MR exams were performed with a 3 T MR system (Magnetom Skyra) and a 7 T MR research system (Magnetom 7 T, Siemens AG, Healthcare Sector, Erlangen, Germany) each in combination with a 32-channel-receive coil. The average time interval between trauma and imaging was 22 months. Location and count of TMBs were independently evaluated by two neuroradiologists on 3 T and 7 T SWI images with similar and additionally increased spatial resolution at 7 T. Inter- and intraobserver reliability was assessed using the interclass correlation coefficient (ICC). Count and diameter of TMB were evaluated with Wilcoxon signed rank test.</p><p>Results</p><p>Susceptibility weighted imaging revealed a total of 485 TMBs (range 1-190, median 25) at 3 T, 584 TMBs (plus 20%, range 1-262, median 30.5) at 7 T with similar spatial resolution, and 684 TMBs (plus 41%, range 1-288, median 39.5) at 7 T with 10-times higher spatial resolution. Hemorrhagic DAI appeared significantly larger at 7 T compared to 3 T (p = 0.005). Inter- and intraobserver correlation regarding the counted TMB was high and almost equal 3 T and 7 T.</p><p>Conclusion</p><p>7 T SWI improves the depiction of small hemorrhagic DAI compared to 3 T and may be supplementary to lower field strengths for diagnostic in inconclusive or medicolegal cases.</p></div

Location and count of DAI-associated TMBs in 10 patients.

<p>Results showing the amount of counted TMBs after consensus of both observers in 10 DAI patients. HR = high resolution; median = median value; n = number of traumatic microbleeds; SD = standard deviation; SWI = susceptibility weighted imaging.</p><p>Location and count of DAI-associated TMBs in 10 patients.</p