Complicated Carotid Artery Plaques and Risk of Recurrent Ischemic Stroke or TIA.

BACKGROUND: Complicated nonstenosing carotid artery plaques (CAPs) are an under-recognized cause of stroke. OBJECTIVES: The purpose of this study was to determine whether complicated CAP ipsilateral to acute ischemic anterior circulation stroke (icCAP) are associated with recurrent ischemic stroke or transient ischemic attack (TIA). METHODS: The CAPIAS (Carotid Plaque Imaging in Acute Stroke) multicenter study prospectively recruited patients with ischemic stroke restricted to the territory of a single carotid artery. Complicated (AHA-lesion type VI) CAP were defined by multisequence, contrast-enhanced carotid magnetic resonance imaging obtained within 10 days from stroke onset. Recurrent events were assessed after 3, 12, 24, and 36 months. The primary outcome was recurrent ischemic stroke or TIA. RESULTS: Among 196 patients enrolled, 104 patients had cryptogenic stroke and nonstenosing CAP. During a mean follow-up of 30 months, recurrent ischemic stroke or TIA occurred in 21 patients. Recurrent events were significantly more frequent in patients with icCAP than in patients without icCAP, both in the overall cohort (incidence rate [3-year interval]: 9.50 vs 3.61 per 100 patient-years; P = 0.025, log-rank test) and in patients with cryptogenic stroke (10.92 vs 1.82 per 100 patient-years; P = 0.003). The results were driven by ipsilateral events. A ruptured fibrous cap (HR: 4.91; 95% CI: 1.31-18.45; P = 0.018) and intraplaque hemorrhage (HR: 4.37; 95% CI: 1.20-15.97; P = 0.026) were associated with a significantly increased risk of recurrent events in patients with cryptogenic stroke. CONCLUSIONS: Complicated CAP ipsilateral to acute ischemic anterior circulation stroke are associated with an increased risk of recurrent ischemic stroke or TIA. Carotid plaque imaging identifies high-risk patients who might be suited for inclusion into future secondary prevention trials. (Carotid Plaque Imaging in Acute Stroke [CAPIAS]; NCT01284933).

No structural brain alterations in new daily persistent headache - a cross sectional VBM/SBM study.

OBJECTIVE: To identify grey matter alterations in patients suffering new daily persistent headache to enrich the pathophysiological concept of this rare headache disorder characterised by a distinct, clearly remembered onset and its instant chronification. METHOD: Magnetic resonance-based voxel-based and surface-based morphometry was used to investigate 23 patients suffering from new daily persistent headache and 23 age- and gender-matched healthy controls with 1.5 Tesla MRI.Independent statistical analysis was performed at three sites using statistical parametric mapping, as well as FSL(FMRIB Software Library)-based approaches. RESULTS: No grey matter changes were detected using this sophisticated and cross-checked method. CONCLUSION: The absence of structural brain changes in patients with new daily persistent headache contribute to the recent discussion regarding structural alterations in primary headache disorders in general and does not provide evidence for grey matter changes being associated with the pathophysiology of new daily persistent headache. Future research will have to determine the underlying pathophysiological mechanisms of this disorder.

Local and systemic therapy of recurrent ependymoma in children and adolescents: short- and long-term results of the E-HIT-REZ 2005 study.

BACKGROUND: Survival in recurrent ependymomas in children and adolescents mainly depends on the extent of resection. Studies on repeated radiotherapy and chemotherapy at relapse have shown conflicting results. METHODS: Using data from the German multi-center E-HIT-REZ-2005 study, we examined the role of local therapy and the efficacy of chemotherapy with blockwise temozolomide (TMZ) in children and adolescents with recurrent ependymomas. RESULTS: Fifty-three patients with a median age of 6.9 years (1.25-25.4) at first recurrence and a median follow-up time of 36 months (2-115) were recruited. Gross- and near-total resection (GTR/NTR) were achieved in 34 (64.2%) patients and associated with a markedly improved 5-year overall survival (OS) of 48.7% vs. 5.3% in less than GTR/NTR. Radiotherapy showed no improvement in OS following complete resection (OS: 70 (CI: 19.9-120.1) vs. 95 (CI: 20.7-169.4) months), but an advantage was found in less than GTR/NTR (OS: 22 (CI: 12.7-31.3) vs. 7 (CI: 0-15.8) months). Following the application of TMZ, disease progression was observed in most evaluable cases (18/21). A subsequent change to oral etoposide and trofosfamide showed no improved response. PF-A EPN were most abundant in relapses (n = 27). RELA-positive EPN (n = 5) had a 5-year OS of 0%. CONCLUSION: The extent of resection is the most important predictor of survival at relapse. Focal re-irradiation is a useful approach if complete resection cannot be achieved, but no additional benefit was seen after GTR/NTR. Longer-term disease stabilization (>6 months) mediated by TMZ occurred in a small number of cases (14.3%).

Complicated Carotid Artery Plaques as a Cause of Cryptogenic Stroke.

BACKGROUND: The underlying etiology of ischemic stroke remains unknown in up to 30% of patients. OBJECTIVES: This study explored the causal role of complicated (American Heart Association-lesion type VI) nonstenosing carotid artery plaques (CAPs) in cryptogenic stroke (CS). METHODS: CAPIAS (Carotid Plaque Imaging in Acute Stroke) is an observational multicenter study that prospectively recruited patients aged older than 49 years with acute ischemic stroke that was restricted to the territory of a single carotid artery on brain magnetic resonance imaging (MRI) and unilateral or bilateral CAP (≥2 mm, NASCET [North American Symptomatic Carotid Endarterectomy Trial] <70%). CAP characteristics were determined qualitatively and quantitatively by high-resolution, contrast-enhanced carotid MRI at 3T using dedicated surface coils. The pre-specified study hypotheses were that that the prevalence of complicated CAP would be higher ipsilateral to the infarct than contralateral to the infarct in CS and higher in CS compared with patients with cardioembolic or small vessel stroke (CES/SVS) as a combined reference group. Patients with large artery stroke (LAS) and NASCET 50% to 69% stenosis served as an additional comparison group. RESULTS: Among 234 recruited patients, 196 had either CS (n = 104), CES/SVS (n = 79), or LAS (n = 19) and complete carotid MRI data. The prevalence of complicated CAP in patients with CS was significantly higher ipsilateral (31%) to the infarct compared with contralateral to the infarct (12%; p = 0.0005). Moreover, the prevalence of ipsilateral complicated CAP was significantly higher in CS (31%) compared with CES/SVS (15%; p = 0.02) and lower in CS compared with LAS (68%; p = 0.003). Lipid-rich and/or necrotic cores in ipsilateral CAP were significantly larger in CS compared with CES/SVS (p < 0.05). CONCLUSIONS: These findings substantiate the role of complicated nonstenosing CAP as an under-recognized cause of stroke. (Carotid Plaque Imaging in Acute Stroke [CAPIAS]; NCT01284933).

Reduced spontaneous low frequency oscillations as measured with functional near-infrared spectroscopy in mild cognitive impairment.

Spontaneous low frequency oscillations (LFO) in functional imaging data have gained increased interest in the study of cognitive decline. Persons diagnosed with mild cognitive impairment (MCI) and Alzheimer's disease (AD) display alterations in their amount of LFO in various brain regions. This is commonly interpreted as disruptions in the autoregulation of the cerebral microvascular system. In the present study LFO (0,07-0,11 Hz) were measured with 52-channel near-infrared spectroscopy (NIRS) in 61 healthy elderly persons (70-76 years), 54 MCI subjects (70-76 years) and 25 healthy young controls (21-48 years) during rest over the frontal and the parietal cortex. Both MCI and healthy elderly controls showed less LFO in the frontal cortex as compared to young subjects. For the parietal cortex a decrease in LFO could be observed for the MCI group in comparison to healthy elderly subjects. Correlations of more LFO with worse performance in neuropsychological tests point to compensatory processes. LFO measured with NIRS might be especially suited for longitudinal studies aiming at predicting cognitive decline.

Decreased hemodynamic response in inferior frontotemporal regions in elderly with mild cognitive impairment.

The verbal fluency task (VFT) is a well-established cognitive marker for mild cognitive impairment (MCI) in the prodromal stage of Alzheimer´s dementia (AD). The behavioral VFT performance of patients allows the prediction of dementia two years later. But effective compensatory mechanism might cover or reduce the predictive value of the VFT. Therefore the aim of this study is to measure the hemodynamic response during VFT in patients with mild cognitive impairment (MCI) to establish the hemodynamic response during the VFT as a screening instrument for the prediction of dementia. One method which allows measuring the hemodynamic response during speech production without severe problems with moving artifacts like in functional magnetic resonance imaging (fMRI) is the functional near-infrared spectroscopy (fNIRS). It is optimal as a screening instrument, as it is easy to apply and without any contraindications. In this study we assessed the hemodynamic response in prefrontal and temporal regions in patients with MCI as well as matched healthy controls with fNIRS. We found a decreased hemodynamic response in the inferior frontotemporal cortex for the MCI group. Our results indicate that a frontotemporal decreased hemodynamic response could serve as a diagnostic biomarker for dementia.

Near-infrared spectroscopy (NIRS) and vagus somatosensory evoked potentials (VSEP) in the early diagnosis of Alzheimer's disease: rationale, design, methods, and first baseline data of the Vogel study.

Functional near-infrared spectroscopy (fNIRS) and vagus somatosensory evoked potentials (VSEP) show deviant patterns in subjects with Alzheimer's disease (AD) compared to healthy controls. We now aimed at testing the predictive value of these methods in the early diagnosis of AD. The Vogel study is a prospective, observational, long-term follow-up study with three time points of investigation within 6 years. Residents of the city of Würzburg born between 1936 and 1941 were recruited. Every participant underwent physical, psychiatric, and laboratory examinations, and performed an intense neuropsychological testing as well as VSEP and NIRS according to the published procedures. 604 subjects were included. Mean age of the participants was 73.9 ± 1.55 years. The most frequent pathological physical and laboratory examination results were observed for blood pressure (62%), body weight (54%), HbA1c (16%), cholesterol (42%), and homocysteine (69%). Comprehensive analysis of cognitive testing showed mild cognitive impairment (MCI) in 12.3% of the patients. Concurrent major depression was found in 6.6% of the patients. We observed a high rate of MCI and somatic comorbidity in our cohort. The high rate of vascular risk factors and depressive symptoms, all of which are known risk factors of AD, is consistent with the notion that there are multiple options to prevent or postpone the onset of AD in a geriatric population like the one of the Vogel studies.

Reduced Activity in the Right Inferior Frontal Gyrus in Elderly APOE-E4 Carriers during a Verbal Fluency Task.

Apolipoprotein-E4 (APOE-E4) is a major genetic risk factor for developing Alzheimer's disease (AD). The verbal fluency task (VFT), especially the subtask category fluency, has shown to provide a good discrimination between cognitively normal controls and subjects with AD. Interestingly, APOE-E4 seems to have no effect on the behavioral performance during a VFT in healthy elderly. Thus, the purpose of the present study was to reveal possible compensation mechanisms by investigating the effect of APOE-E4 on the hemodynamic response in non-demented elderly during a VFT by using functional near-infrared spectroscopy (fNIRS). We compared performance and hemodynamic response of high risk APOE-E4/E4, -E3/E4 carriers with neutral APOE-E3/E3 non-demented subjects (N = 288; 70-77 years). No difference in performance was found. APOE-E4/E4, -E3/E4 carriers had a decreased hemodynamic response in the right inferior frontal junction (IFJ) with a corresponding higher response in the left middle frontal gyrus (MFG) during category fluency. Performance was correlated with the hemodynamic response in the MFG. We assume a compensation of decreased IFJ brain activation by utilizing the MFG during category fluency and thus resulting in no behavioral differences between APOE-groups during the performance of a VFT.

Increased cortical activation upon painful stimulation in fibromyalgia syndrome.

BACKGROUND: Fibromyalgia syndrome (FMS) is a chronic condition characterized by widespread pain and associated symptoms. We investigated cerebral activation in FMS patients by functional near-infrared spectroscopy (fNIRS). METHODS: Two stimulation paradigms were applied: a) painful pressure stimulation at the dorsal forearm; b) verbal fluency test (VFT). We prospectively recruited 25 FMS patients, ten patients with unipolar major depression (MD) without pain, and 35 healthy controls. All patients underwent neurological examination and all subjects were investigated with questionnaires (pain, depression, FMS, empathy). RESULTS: FMS patients had lower pressure pain thresholds than patients with MD and controls (p < .001) and reported higher pain intensity (p < 0.001). Upon unilateral pressure pain stimulation fNIRS recordings revealed increased bilateral cortical activation in FMS patients compared to controls (p < 0.05). FMS patients also displayed a stronger contralateral activity over the dorsolateral prefrontal cortex in direct comparison to patients with MD (p < 0.05). While all three groups performed equally well in the VFT, a frontal deficit in cortical activation was only found in patients with depression (p < 0.05). Performance and cortical activation correlated negatively in FMS patients (p < 0.05) and positively in patients with MD (p < 0.05). CONCLUSION: Our data give further evidence for altered central nervous processing in patients with FMS and the distinction between FMS and MD. TRIAL REGISTRATION: ISRCTN registry ID ISRCTN15015327 (24.09.2015).

Neural correlates of a standardized version of the trail making test in young and elderly adults: a functional near-infrared spectroscopy study.

The trail making test (TMT) is a widely applied diagnostic tool measuring executive functioning in order to discriminate between healthy and pathological aging processes. However, due to its paper-and-pencil nature it is difficult to adapt for functional brain imaging. Related neural underpinnings even in healthy aging are mostly unknown since no consistent administration for imaging is available. In this study a standardized implementation of the TMT for functional near-infrared spectroscopy (fNIRS) is proposed to investigate associated frontal cortex activation in healthy young (mean age 25.7 ± 3.02 years) and elderly adults (mean age 70.95 ± 3.55 years). The TMT consisted of a number condition (TMT-A), an alternating number and letter condition (TMT-B) as well as a control task. Behavioral results demonstrated that elderly participants performed slower but committed a similar number of errors compared to younger adults. The fNIRS results showed that particularly the TMT-B provoked bilateral activation in the ventro- and dorsolateral prefrontal cortex (vlPFC and dlPFC) as well as in premotor regions. Elderly participants displayed more significantly activated channels and a different activation pattern compared to younger participants especially manifesting in more bilateral dlPFC activation. In line with the hemispheric asymmetry reduction in elderly adults (HAROLD) model, the results were interpreted as an additional need for cognitive control resources in elderly participants. This study succeeded in implementing an appropriate version of the TMT for fNIRS and helps elucidating neural aging effects associated with this task.

Vagus somatosensory evoked potentials are delayed in Alzheimer's disease, but not in major depression.

In Alzheimer's disease (AD), the degeneration of brainstem nuclei is different from major depression (MD). Thus, vagus somatosensory evoked potentials (VSEP) proposed for the functional assessment of brainstem nuclei should show prolonged latencies in AD but not in MD. In 55 AD patients, 57 MD patients and two age-matched control groups evoked potentials were recorded upon stimulation of the auricular branch of the vagus nerve. In the AD, not in the MD group, latencies were significantly longer as compared to controls. Thus, the method of VSEP could contribute to the important differential diagnosis of AD and MD in elderly patients.

Altered parietal brain oxygenation in Alzheimer's disease as assessed with near-infrared spectroscopy.

OBJECTIVE: Visuospatial deficits are among the first symptoms of Alzheimer disease (AD) and linked to lower activation in the superior parietal cortex as assessed with functional imaging. Near-infrared spectroscopy (NIRS) is an optical method to measure changes in the concentration of oxygenated hemoglobin and deoxygenated hemoglobin in the microvascular system of the cortex. Because of its advantages in measurement situation, NIRS has proven to be especially suited for investigating psychiatric patients. The aim of this study was to probe the activation of parietal regions in patients with AD, performing a visuospatial task by means of functional NIRS (fNIRS). METHODS: Thirteen patients with suspected mild AD and 13 healthy subjects comparable in age and gender were investigated while working on a modified version of the Benton Line Orientation Task. RESULTS: During the spatial task, healthy subjects showed explicit parietal activation, whereas patients displayed only activation during the control task. Interestingly, there was no difference in visuospatial performance between the two groups. CONCLUSION: The results indicate that fNIRS is able to measure parietal activation deficits in patients with AD, which could be developed into an early detection method in the future.