Integrating EEG and Machine Learning to Analyze Brain Changes during the Rehabilitation of Broca's Aphasia.

The fusion of electroencephalography (EEG) with machine learning is transforming rehabilitation. Our study introduces a neural network model proficient in distinguishing pre- and post-rehabilitation states in patients with Broca's aphasia, based on brain connectivity metrics derived from EEG recordings during verbal and spatial working memory tasks. The Granger causality (GC), phase-locking value (PLV), weighted phase-lag index (wPLI), mutual information (MI), and complex Pearson correlation coefficient (CPCC) across the delta, theta, and low- and high-gamma bands were used (excluding GC, which spanned the entire frequency spectrum). Across eight participants, employing leave-one-out validation for each, we evaluated the intersubject prediction accuracy across all connectivity methods and frequency bands. GC, MI theta, and PLV low-gamma emerged as the top performers, achieving 89.4%, 85.8%, and 82.7% accuracy in classifying verbal working memory task data. Intriguingly, measures designed to eliminate volume conduction exhibited the poorest performance in predicting rehabilitation-induced brain changes. This observation, coupled with variations in model performance across frequency bands, implies that different connectivity measures capture distinct brain processes involved in rehabilitation. The results of this paper contribute to current knowledge by presenting a clear strategy of utilizing limited data to achieve valid and meaningful results of machine learning on post-stroke rehabilitation EEG data, and they show that the differences in classification accuracy likely reflect distinct brain processes underlying rehabilitation after stroke.

Iatrogenic cerebral amyloid angiopathy: A multinational case series and individual patient data analysis of the literature.

BACKGROUND: The transmission of amyloid ß (Aß) in humans leading to iatrogenic cerebral amyloid angiopathy (iCAA) is a novel concept with analogies to prion diseases. However, the number of published cases is low, and larger international studies are missing. AIMS: We aimed to build a large multinational collaboration on iCAA to better understand the clinical spectrum of affected patients. METHODS: We collected clinical data on patients with iCAA from Austria, Croatia, Italy, Slovenia, and Spain. Patients were included if they met the proposed Queen Square diagnostic criteria (QSC) for iCAA. In addition, we pooled data on disease onset, latency, and cerebrospinal fluid (CSF) biomarkers from previously published iCAA cases based on a systematic literature review. RESULTS: Twenty-seven patients (22% women) were included in this study. Of these, 19 (70%) met the criteria for probable and 8 (30%) for possible iCAA. Prior neurosurgical procedures were performed in all patients (93% brain surgery, 7% spinal surgery) at median age of 8 (interquartile range (IQR) = 4-18, range = 0-26 years) years. The median symptom latency was 39 years (IQR = 34-41, range = 28-49). The median age at symptom onset was 49 years (IQR = 43-55, range = 32-70). Twenty-one patients (78%) presented with intracranial hemorrhage and 3 (11%) with seizures. CONCLUSIONS: Our large international case series of patients with iCAA confirms a wide age boundary for the diagnosis of iCAA. Dissemination of awareness of this rare condition will help to identify more affected patients.

A Case Series of Four Patients with Artery of Percheron Occlusion over a Three-Month Period.

Here, we present a case series of four patients diagnosed with acute ischaemic stroke due to occlusion of the artery of Percheron (AOP), a rare stroke variant, observed in a single emergency centre within a three-month period. AOP occlusion is characterized by bilateral thalamic infarction with or without involvement of the mesencephalon. The presenting symptoms are diverse and not specific, but commonly include disturbance of consciousness, memory impairment, and vertical gaze palsy. In addition, due to the location of the infarction, imaging recognition is challenging and AOP occlusion often remains undiagnosed. This paper emphasizes the necessity of early recognition and appropriate management of AOP occlusion to significantly impact patient outcomes. Moreover, we argue that the condition might be more common than previously thought and that misdiagnosis or delay in diagnosis may lead to inappropriate treatment and potential failure to apply thrombolysis within the required timeframe.

Treatment of Acute Ischaemic Stroke and Concomitant Multiple Arterial Splanchnic Thromboses in a Patient with Immune Thrombocytopenia on Thrombopoietin Agonist: A Case Report.

Immune thrombocytopenia (ITP) is an autoimmune blood disorder characterised by isolated severe thrombocytopenia. Arterial thrombotic events, such as acute ischaemic stroke (AIS), are rare complications. A 56-year-old woman with chronic ITP on eltrombopag and dexamethasone therapy presented to the emergency department due to AIS in the vertebrobasilar territory, and lower abdominal pain. The computed tomography (CT) scan of the head was unremarkable, whereas CT angiography revealed left vertebral artery occlusion. As the platelet count was sufficient, intravenous thrombolysis (IVT) was initiated. However, after 15 min, an anaphylactic reaction occurred, which was appropriately solved. Although the IVT was prematurely stopped, the NIHSS score improved from 7 to 2, and the follow-up head CT scan remained unremarkable. CT angiography of the thoracoabdominal aorta revealed multiple thrombi in the infrarenal aorta, inferior mesenteric artery (IMA), and left renal artery. The abdominal pain subsided after IVT, but recurred within 24 h. Repeated CT angiography showed ischaemia of the descending colon, with persistent IMA occlusion. After the hemicolectomy condition stabilised. Discrete left-sided ataxia and impaired sensation were the only neurological sequelae. We found two articles reporting only three patients with ITP who suffered AIS and were treated with IVT. A favourable outcome was observed in two cases, while one patient suffered an intracranial haemorrhage (ICH) and died. A review of AIS cases with undefined thrombocytopenia treated with IVT reported ICH in up to 6.8% of patients. Our case suggests that IVT for AIS may be effective in patients with ITP. Further data are needed to better clarify this issue.

Recurrent Strokes in Patients With Atrial Fibrillation Treated With Direct Oral Anticoagulant Agents.

Recurrent ischemic strokes (IS) in patients treated with direct oral anticoagulant agents (DOACs) are rare. Knowledge regarding the type of recurrent IS and predisposing factors is insufficient. We analyzed a cohort of 1001 patients (77.6 ± 9.2 years; females: 57.1%) with non-valvular atrial fibrillation (AF) treated with DOACs as part of secondary prevention after initial IS or transient ischemic attack. Cardiovascular risk factors, stroke etiology, and Fazekas score based on computed tomography images at the time of the initial IS were assessed. Low Fazekas scores were defined as 0 or 1 and high scores were 2 or 3. Recurrent IS occurred in 46 patients (4.6%, annual rate 1.6%) during the observation period (2.8 ± 1.8 years). Stroke was cardioembolic in 20 patients (43.5%), lacunar in 19 patients (37.5%) and large artery stroke in 6 patients (19.2%). Non-cardioembolic stroke was more common (75.0 vs 26.7%; P = .002) in patients with high Fazekas scores. Arterial hypertension was more frequent (P = .027) in patients with high (93.3%) vs low (68.8%) Fazekas scores. Recurrent IS was predominantly non-cardioembolic with higher Fazekas score and arterial hypertension as predisposing factors. The reported hypothesis-generating results regarding the clinical relevance of the Fazekas score should be further evaluated.

Independent Significance of Visual Assessment of Perfusion CT Maps in Anterior Circulation Stroke Patients Treated with Mechanical Thrombectomy.

BACKGROUND: In the absence of an automated software analysis, the role of computed tomography perfusion (CTP) in a real time clinical practice is not well established. We evaluated the clinical significance of a widely accessible and simple visual grading scale of CTP in the anterior circulation of acute ischemic stroke (AIS) patients treated with mechanical thrombectomy (MT). METHODS: The single center consecutive CT investigations of AIS patients treated with MT in the anterior circulation have been evaluated retrospectively. ASPECT score and collateral circulation evaluation based on the Maas score were determined. Time to peak parametric maps, derived from CTP, were graded into four categories, from least to most favorable. The primary endpoint was functional outcome evaluated as modified Rankin Scale (mRS) ≤ 2 at 90 days after MT. RESULTS: We included 318 patients in the analysis; 142 (45%) patients had mRS ≤ 2 after 90 days, mortality rate was 24%. Higher CTP and Maas score were significantly correlated with better clinical outcome (Pearson χ2 25.0 and 37.7, respectively; p < 0.01). Collateral circulation and CTP grades were strongly interrelated (Pearson χ2 78.6; p < 0.01). The CTP grade demonstrated statistically significant independent correlation with the clinical outcome irrespective of the collateral circulation grade, ASPECT score and age (OR 2.5; p = 0.011). The correlation was more pronounced in patients with normal collateral circulation (OR 3.27; p = 0.029). CONCLUSION: We demonstrated that both visually graded CTP and collateral circulation grade strongly correlated with the clinical outcome of MT in the anterior circulation of AIS patients. Importantly, CTP correlated with the clinical outcome independent of the collateral circulation.

Clinical and Radiological Characteristics Associated with Respiratory Failure in Unilateral Lateral Medullary Infarction.

BACKGROUND: The prognosis for unilateral lateral medullary infarction (ULMI) is generally good but may be aggravated by respiratory failure with fatal outcome. Respiratory failure has been reported in patients with severe bulbar dysfunction and large rostral medullary lesions, but its associated factors have not been systematically studied. We aimed to assess clinical and radiological characteristics associated with respiratory failure in patients with pure acute ULMI. MATERIALS AND METHODS: Seventy-one patients (median age 55 years, 59 males) with MRI-confirmed acute pure ULMI were studied retrospectively. Clinical characteristics were assessed and bulbar symptoms were scored using a scale developed for this study. MRI lesions were classified into 4 groups based on their vertical extent (localized/extensive) and the involvement of the open and/or closed medulla. Clinical characteristics, bulbar scores and MRI lesion characteristics were compared between patients with and without respiratory failure. RESULTS: Respiratory failure occurred in 8(11%) patients. All patients with respiratory failure were male (p = 0.336), had extensive lesions involving the open medulla (p = 0.061), progression of bulbar symptoms (p=0.002) and aspiration pneumonia (p < 0.001). Peak bulbar score (OR, 7.9 [95% CI, 2.3-160.0]; p < 0.001) and older age (OR, 1.2 [95%CI, 1.0-1.6]; p=0.006) were independently associated with respiratory failure. CONCLUSIONS: Extensive damage involving the open/rostral medulla, clinically presenting with severe bulbar dysfunction, in conjunction with factors such as aspiration pneumonia and older age appears to be crucial for the development of respiratory failure in pure ULMI. Further prospective studies are needed to identify other potential risk factors, pathophysiology, and effective preventive measures for respiratory failure in these patients.

Intravenous Thrombolysis After Dabigatran Reversal by Idarucizumab: A Systematic Review of the Literature.

Background and Purpose: Idarucizumab achieves instant reversal of anticoagulation and enables intravenous thrombolysis (IVT) in dabigatran-treated acute ischemic stroke (AIS) patients. AIS in dabigatran-treated patients is a rare event, therefore the experience is limited. A review of all published cases was performed to evaluate the safety and effectiveness of this therapeutic strategy. Methods: We searched PubMed and Scopus for all published cases of IVT after reversal with idarucizumab in dabigatran-treated AIS patients. The outcomes were safety assessed by hemorhagic transformation (HT), symptomatic intracranial hemorrhage (SICH) and death, and efficacy assessed by National Institutes of Health Stroke Scale (NIHSS) reduction. Results: We identified 251 AIS patients (39,9% females) with an average age of 74 years. HT, SICH, and death were reported in 19 (7.6%), 9 (3.6%), and 21 (8.4%) patients, respectively. Patients experiencing HT presented with more severe strokes (median NIHSS on admission: 21 vs. 8, p < 0.001; OR: 1.12, 95% CI: 1.05-1.20). After IVT there was a significant NIHSS reduction of 6 points (IQR:3-10, p < 0.001) post-stroke and linear regression revealed a correlation of admission NIHSS to NIHSS reduction (p < 0.001). Conclusions: In this systematic review of all published cases of IVT in dabigatran-treated AIS patients after reversal with idarucizumab the rates of HT, SICH and mortality, as well as NIHSS reduction, were comparable with previous studies in non-anticoagulated patients. This provides reassuring evidence about the safety and efficacy of this therapeutic strategy.

Breathing patterns in relation to sleep stages in acute unilateral lateral medullary infarction: An exploratory study.

Our aim was to perform an exploratory study of various irregular breathing patterns (IBPs) across different sleep stages in patients with acute unilateral lateral medullary infarction (ULMI) and compare them to apparently healthy individuals. Polysomnography (PSG) was analyzed for IBPs, such as periodic breathing, ataxic breathing and tachypnea. IBPs were found in 52 % of healthy and 90 % of ULMI subjects (p = 0.001) and occurred in long (≥ 10 min) episodes in 8% of healthy and 68 % of ULMI (p < 0.001). In healthy subjects, short (< 10 min) episodes of mild to moderate ataxic breathing were observed in wakefulness and light sleep and short episodes of periodic breathing upon sleep onset. In ULMI, the most common IBPs were ataxic and periodic breathing (80 % of patients), followed by shallow tachypnea (28 %). Ataxic breathing predominated in wakefulness, ataxic or periodic breathing in light sleep, while breathing tended to normalize in deep and REM sleep. Considering the IBPs occurring in the healthy group as physiological, probably pathological breathing patterns (tachypnea, long episodes of moderate/severe ataxic or long episodes of periodic breathing) occurred in 67 % of ULMI patients. Our findings suggest that ULMI might exacerbate physiological sleep-stage-dependent breathing pattern irregularities, such as ataxic and periodic breathing, in terms of intensity and duration or might even induce non-physiological IBP, such as shallow tachypnea with sustained hypoxia.

Prospective study of sleep-disordered breathing in 28 patients with acute unilateral lateral medullary infarction.

OBJECTIVE: Acute unilateral lateral medullary infarction (ULMI) is complicated by respiratory failure in 2-6% of patients. However, studies investigating milder respiratory disorders not leading to overt respiratory failure, i.e., sleep-disordered breathing (SDB) and its outcome, are lacking. The aim of our study was to identify and prospectively follow SDB in acute ULMI. METHODS: We prospectively followed 28 patients with MRI-confirmed acute ULMI. Polysomnography (PSG) was performed 1-3 times in the acute phase (at 1-4, 5-10, and 14-21 days after onset of symptoms) and after 3-6 months. PSG recordings in the acute phase were analyzed and compared to the follow-up. RESULTS: Apnea-hypopnea index (AHI) ≥ 5/h, AHI ≥ 15/h, and AHI ≥ 30/h in the acute phase were observed in 22 (79%), 19 (68%), and 10 (36%) patients, respectively. CSA, OSA, mixed CSA/OSA, or multiple interchanging SDB types were observed in the acute phase in 12 (43%), 2 (7%), 2 (7%), and 6 (21%) patients, respectively. Peak AHI varied in individual patients (median at 7 (3-14) days after onset). At follow-up, AHI and central AHI tended to decrease (p = 0.007, p = 0.003, respectively), obstructive AHI did not change (p = 0.396). Sleep architecture partially improved with significantly higher percentage of N2 and lower percentage of wakefulness after sleep onset (p = 0.007, p = 0.012, respectively). CONCLUSIONS: Our data show that SDB, particularly CSA, is common in the acute phase of ULMI and that the frequency of central events decreases in the subacute phase. Further studies are needed to clarify the clinical significance and possible treatment options of SDB in these patients.

Intravenous Thrombolysis After Idarucizumab Application in Acute Stroke Patients-A Potentially Increased Sensitivity of Thrombi to Lysis?

BACKGROUND: Rapid inactivation of dabigatran by its specific inhibitor idarucizamab allows intravenous thrombolysis (IVT) in patients suffering ischemic stroke while being treated with dabigatran. Only limited data of this approach is available and numerous questions regarding efficacy/safety remain to be answered. Herein, we present the findings from the Slovenian national cohort study. METHODS: Retrospective analysis of all stroke patients treated with idarucizumab and IVT (n = 11) in the period from July 2016 to February 2018 from Slovenian region were analyzed. RESULTS: The indication for dabigatran treatment in all 11 cases was nonvalvular atrial fibrillation. Importantly, 6 out of 11 cases were classified as severe ischemic strokes (National Institutes of Health Stroke Scale; NIHSS ≥ 10) with a median NIHSS 13. At admission, prolonged activated partial thromboplastin time was present in 9 patients indicating therapeutic anticoagulation activity. The average door-to-needle time was 156 minutes. After 3 months, 9 patients had a modified Rankin Score of less than or equal to 2 and 7 patients had mRS less than 1 whereas, 2 patients died due to symptomatic intracranial hemorrhage (sICH); 1 due to spontaneous sICH, and the other due to a large ischemic stroke with hemorrhagic transformation. No thrombotic complications were observed. CONCLUSIONS: Our data show that IVT after idarucizumab administration is a safe and effective method of treatment in ischemic stroke patients on dabigatran. We recorded a higher proportion of patients with favorable outcome as well as with sICH compared to the randomized controlled studies which could suggest a higher sensitivity of thrombi to IVT in dabigatran treated patients.

Early Outcome after Intracranial Hemorrhage Related to Non-Vitamin K Oral Anticoagulants.

BACKGROUND: Intracranial hemorrhage (ICH) is a serious, life-threatening, but fortunately rare complication of non-vitamin K oral anticoagulant (NOAC) therapy. There are limited data on NOAC-related ICH prognosis. METHODS: All consecutive patients admitted to a single center due to acute NOAC-related ICH from September 2012 until the beginning of 2017 were included. Risk factors, type of NOAC, and location of ICH were evaluated. Risk for ischemic and bleeding events and clinical status upon admission and at discharge were evaluated using standard scales. RESULTS: Thirty-four patients aged 77.8 ± 8.3 years with NOAC-related ICH were included. The main predisposing risk factors were age and arterial hypertension. The median CHA2DS2-VASc score was 3.4 and the median HAS-BLED score was 1.8. Eighteen patients were treated with rivaroxaban, 11 with dabigatran, and 5 with apixaban. Ten patients (29%) had a favorable outcome with a modified Rankin Scale score ≤2 and 13 patients (38%) died. The location of the ICH was mainly intraparenchymal and subdural. CONCLUSIONS: Our retrospective single-center study shows that the mortality rate with NOAC-related ICH is <40%, which makes it comparable to that with vitamin K antagonist-related ICH.

Neuropathological criteria of anti-IgLON5-related tauopathy.

We recently reported a novel neurological syndrome characterized by a unique NREM and REM parasomnia with sleep apnea and stridor, accompanied by bulbar dysfunction and specific association with antibodies against the neuronal cell-adhesion protein IgLON5. All patients had the HLA-DRB1*1001 and HLA-DQB1*0501 alleles. Neuropathological findings in two patients revealed a novel tauopathy restricted to neurons and predominantly involving the hypothalamus and tegmentum of the brainstem. The aim of the current study is to describe the neuropathological features of the anti-IgLON5 syndrome and to provide diagnostic levels of certainty based on the presence of associated clinical and immunological data. The brains of six patients were examined and the features required for the neuropathological diagnosis were established by consensus. Additional clinical and immunological criteria were used to define "definite", "probable" and "possible" diagnostic categories. The brains of all patients showed remarkably similar features consistent with a neurodegenerative disease with neuronal loss and gliosis and absence of inflammatory infiltrates. The most relevant finding was the neuronal accumulation of hyperphosphorylated tau composed of both three-repeat (3R) and four-repeat (4R) tau isoforms, preferentially involving the hypothalamus, and more severely the tegmental nuclei of the brainstem with a cranio-caudal gradient of severity until the upper cervical cord. A "definite" diagnosis of anti-IgLON5-related tauopathy is established when these neuropathological features are present along with the detection of serum or CSF IgLON5 antibodies. When the antibody status is unknown, a "probable" diagnosis requires neuropathological findings along with a compatible clinical history or confirmation of possession of HLA-DRB1*1001 and HLA-DQB1*0501 alleles. A "possible" diagnosis should be considered in cases with compatible neuropathology but without information about a relevant clinical presentation and immunological status. These criteria should help to identify undiagnosed cases among archival tissue, and will assist future clinicopathological studies of this novel disorder.

Ratio between carotid artery stiffness and blood flow - a new ultrasound index of ischemic leukoaraiosis.

BACKGROUND: Ischemic leukoaraiosis (ILA) is associated with cognitive decline and aging. Its pathophysiology is believed to be ischemic in origin due to its association with cerebrovascular risk factors and similarity in location to lacunar infarctions. ILA diagnosis is still based on magnetic resonance imaging (MRI) as well as exclusion of other causes of white matter hyperintensities. So far, there are no known confirming diagnostic tests of ILA. Ultrasound studies have recently shown increased large artery stiffness, increased cerebrovascular resistance, and lower cerebral blood flow in patients with ILA. Increased arterial stiffness and decreased blood flow could have a synergistic effect, and their ratio could be a useful diagnostic index of ILA. METHODS: In this post hoc analysis, we introduced new ILA indices (ILAi) that are ratios of the carotid stiffness parameters (pulse wave velocity beta [PWVß], pressure-strain elasticity modulus [Ep], ß index), and diastolic and mean blood flows in the internal carotid artery: Q-ICAd and Q-ICAm. We compared the ILAi of 52 patients with ILA and 44 sex- and risk factor-matched controls with normal MRI of the head. ILA diagnosis was based on MRI and exclusion of other causes of white matter hyperintensities. The diagnostic significance of ILAi for the prediction of ILA was analyzed. RESULTS: All ILAi significantly differed between the groups; the most significant were PWVß/Q-ICAd (ILA group: 1.96±0.64 vs control group: 1.56±0.40, P=0.001) and PWVß/Q-ICAm (ILA group: 1.13±0.32 vs control group: 0.94±0.25, P=0.003). All ILAi were significantly associated with ILA (P<0.01) and were significant independent predictors of ILA. All ILAi were also sensitive and specific for predicting ILA (area under the curve: 0.632-0.683, P<0.05). CONCLUSION: The new ultrasound indices significantly differed between patients with ILA and the control group and were significant predictors of ILA. A combination of lower carotid blood flow and increased carotid stiffness represented as ILAi probably has a diagnostic value in patients with ILA.

Characteristics of Cerebral Hemodynamics in Patients with Ischemic Leukoaraiosis and New Ultrasound Indices of Ischemic Leukoaraiosis.

OBJECTIVE: The diagnosis of ischemic leukoaraiosis (ILA) is based on head magnetic resonance imaging (MRI) and exclusion of other causes of white matter hyperintensities (WMHs). Recent studies have shown increased arterial stiffness and diminished carotid flow in ILA patients. So far, there are very little data on intracerebral hemodynamic parameters in ILA. Due to the specific structure of the intracranial arteries, our aim was to investigate intracerebral hemodynamic parameters in ILA patients and, possibly, to find a reliable ultrasound index of combined intra- and extracranial cerebral arteries. METHODS: We compared different hemodynamic parameters in the middle cerebral artery (MCA) and local carotid stiffness parameters in 53 ILA patients to 40 gender and risk factor-matched controls with normal head MRI. The ILA diagnosis was based on head MRI and exclusion of other causes of WMH. In addition, we introduced new ischemic leukoariosis indices (ILAi) that are ratios of carotid stiffness parameters and MCA mean blood flow velocity. The diagnostic significance of ILAi for the prediction of ILA was analyzed. RESULTS: We found significantly lower diastolic, systolic, and mean MCA blood flow velocities and increased carotid stiffness in the ILA group (P ≤ .05). All ILAi significantly differed between the groups (P < .05), were significantly associated with ILA (P < .01), and were sensitive and specific for predicting ILA (P < .05). CONCLUSION: MCA blood flow velocities in ILA patients are lower compared to risk factor-matched controls. A combination of lower velocities and increased carotid stiffness represented as ILAi could have a potential diagnostic value for ILA.

Carotid Arterial Hemodynamic in Ischemic Levkoaraiosis Suggests Hypoperfusion Mechanism.

BACKGROUND: Leukoaraiosis (ILA) is believed to be ischaemic in origin due to its similar location as that of lacunar infarctions and its association with cerebrovascular risk factors. However, its pathophysiology is not well understood. The ischaemic injuries may be a result of increased pulsatility or cerebral hypo-perfusion. We used carotid duplex ultrasound to prove that the underlying mechanism is hypo-perfusion. METHODS: We compared 55 ILA patients to 44 risk factor-matched controls with normal magnetic resonance imaging (MRI) of the head. ILA diagnosis was based on MRI and was further categorised according to the Fazekas scale. We measured carotid artery blood flow velocity and diameter and calculated carotid blood flow and resistance indexes. RESULTS: Blood flow velocities and blood flows were significantly lower in the ILA group, including diastolic, systolic and mean pressures (p ≤ 0.05). The resistance indices were higher in the ILA group, but the differences were not statistically significant. All the velocities and blood flows showed a decreasing trend with higher Fazekas score, whereas resistance indexes showed an increasing trend. CONCLUSIONS: Lower blood flow and higher resistance of carotid arteries are consistent with the hypo-perfusion theory of ILA. Carotid ultrasound could have a diagnostic and prognostic role in ILA patients.

Ultrasound diagnosis of carotid artery stiffness in patients with ischemic leukoaraiosis.

The pathophysiology of ischemic leukoaraiosis (ILA) is unknown. It was recently found that ILA patients have increased aortic stiffness. Carotid stiffness is a more specific parameter and could have value as a non-invasive diagnostic value for ILA. Therefore, using color-coded duplex sonography, we compared local carotid stiffness parameters of 59 patients with ILA with those of 45 well-matched controls. The diagnosis of ILA was based on exclusion of other causes of white matter changes seen on magnetic resonance imaging. Pulse wave velocity ß (PWVß, m/s), pressure-strain elasticity modulus (Ep, kPa), ß index and augmentation index (Aix, %) values were higher and arterial compliance (AC, mm(2)/kPa) values were lower in the ILA group; however, only Ep and PWVß reached statistical significance (p ≤ 0.05). ß, Ep and PWVß exhibited an increasing trend with higher Fazekas score, though only Ep reached significance (p = 0.05). The main conclusion was that Ep and PWVß could have a diagnostic role in patients with ILA.

Cerebral endothelial function determined by cerebrovascular reactivity to L-arginine.

Endothelium forms the inner cellular lining of blood vessels and plays an important role in many physiological functions including the control of vasomotor tone. Cerebral endothelium is probably one of the most specific types but until recently it was impossible to determine its function. In this review, the role of cerebrovascular reactivity to L-arginine (CVR-L-Arg) for assessment of cerebral endothelial function is discussed. L-Arginine induces vasodilatation through enhanced production of nitric oxide (NO) in the cerebral endothelium. Transcranial Doppler sonography is used for evaluation of cerebral blood flow changes. The method is noninvasive, inexpensive, and enables reproducible measurements. CVR-L-Arg has been compared to flow-mediated dilatation as a gold standard for systemic endothelial function and intima-media thickness as a marker for morphological changes. However, it seems to show specific cerebral endothelial function. So far CVR-L-Arg has been used to study cerebral endothelial function in many pathological conditions such as stroke, migraine, etc. In addition CVR-L-Arg has also proven its usefulness in order to show potential improvement after pharmacological interventions. In conclusion CVR-L-Arg is a promising noninvasive research method that could provide means for evaluation of cerebral endothelial function in physiological and pathological conditions.

Moyamoya syndrome with arteriovenous dural fistula after head trauma.

Moyamoya vascular pattern and dural arteriovenous fistula (dAVF) are rare vascular abnormalities and both can be secondary to head trauma. The role of dural angiogenesis in the pathophysiology of vascular malformation is rather unclear. We report a unique case of moyamoya vasculopathy simultaneously associated with dAVF after heavy head trauma. It seems that both moyamoya syndrome and dAVFs are associated with dural angiogenesis induced by head trauma. The interrelationship between vascular abnormalities is complex and unclear.

Associations between cerebral and systemic endothelial function in migraine patients: a post-hoc study.

BACKGROUND: There is a growing interest in the role of the endothelium in migraine. Recently, our group showed differences in endothelial function between the anterior and posterior cerebral circulation in healthy subjects, reduced vasodilatatory capacity of the posterior cerebral circulation and unimpaired systemic endothelial function in migraine patients without comorbidities. However, the relationship between cerebral and systemic endothelial function and the anterior and posterior cerebral endothelial function in migraine patients is still not clear. METHODS: We compared cerebral and systemic endothelial function through post-hoc linear regression analysis of cerebrovascular reactivity (CVR) to L-arginine between the middle cerebral artery (MCA) and flow-mediated vasodilatation (FMD) of the right brachial artery and the posterior cerebral artery (PCA) and FMD in migraine patients without comorbidities and in healthy subjects. The anterior and posterior cerebral endothelial function was also compared using post-hoc linear regression analysis between CVR to L-arginine in the MCA and the PCA. RESULTS: No significant correlation was found between CVR to L-arginine in the MCA and FMD and in the PCA and FMD in migraine patients with aura (p = 0.880 vs. p = 0.682), without aura (p = 0.153 vs. p = 0.179) and in healthy subjects (p = 0.869 vs. p = 0.662). On the other hand, we found a significant correlation between CVR to L-arginine in the MCA and PCA in migraine patients with aura (p = 0.004), without aura (p = 0.001) and in healthy subjects (p = 0.002). Detailed analysis of the linear regression between all migraine patients and healthy subjects did not show any difference in the regression coefficient (slope) (p = 0.382). However, a significant difference in curve elevation (intercept) was found (p = 0.002). CONCLUSIONS: Our study suggests that the endothelial function in the cerebral and systemic circulation might be different in migraine patients without comorbidities, while that of the anterior and posterior cerebral circulation might be coupled. These results could improve understanding of endothelial function in migraine patients without comorbidities.