Atrial fibrosis in embolic stroke of undetermined source: A multicenter study.

BACKGROUND AND PURPOSE: Left atrial (LA) cardiac disease is a suspected cause of embolic stroke of undetermined source (ESUS). We tested the hypothesis that LA fibrosis, quantified using late-gadolinium-enhancement magnetic resonance imaging (LGE-MRI), predicts recurrent stroke or atrial fibrillation (AF) in patients with ESUS. METHODS: We compared atrial fibrosis in healthy controls and patients with lacunar stroke, ESUS, and known AF with or without prior stroke. We followed patients with ESUS prospectively for the primary outcome of recurrent ischemic stroke, incident AF, or both. RESULTS: We enrolled 203 patients from three centers: 103 patients without AF (35 healthy controls, 15 with lacunar strokes, 53 with ESUS) and 100 patients with AF (50 with and 50 without prior stroke). Patients with ESUS had significantly higher atrial fibrosis (15.0 ± 6.2%) compared to healthy controls (8.1 ± 7.9%; <0.0001) and compared to lacunar stroke patients (10.8 ± 8.4; p = 0.02), but had comparable fibrosis to patients with AF with (17.9 ± 11.4%) or without prior stroke (16.6 ± 9.2%; p = NS for both). Over a mean follow-up of 19 months, nine of 53 patients (16.9%) with ESUS experienced the combined primary outcome, which included six patients (11.3%) with recurrent ischemic stroke and five patients with incident AF (9.4%). Patients with ESUS with fibrosis ≥12% had a higher proportion of the combined outcome: 25.0% vs. 4.8%; p = 0.039. CONCLUSIONS: Patients with ESUS demonstrate atrial fibrosis comparable to that seen in AF. Atrial fibrosis ≥12% was associated with recurrent stroke, incident AF or both. This subgroup of ESUS patients may benefit from anticoagulation for secondary prevention of ischemic stroke.

Computational modeling identifies embolic stroke of undetermined source patients with potential arrhythmic substrate.

Cardiac magnetic resonance imaging (MRI) has revealed fibrosis in embolic stroke of undetermined source (ESUS) patients comparable to levels seen in atrial fibrillation (AFib). We used computational modeling to understand the absence of arrhythmia in ESUS despite the presence of putatively pro-arrhythmic fibrosis. MRI-based atrial models were reconstructed for 45 ESUS and 45 AFib patients. The fibrotic substrate's arrhythmogenic capacity in each patient was assessed computationally. Reentrant drivers were induced in 24/45 (53%) ESUS and 22/45 (49%) AFib models. Inducible models had more fibrosis (16.7 ± 5.45%) than non-inducible models (11.07 ± 3.61%; p<0.0001); however, inducible subsets of ESUS and AFib models had similar fibrosis levels (p=0.90), meaning that the intrinsic pro-arrhythmic substrate properties of fibrosis in ESUS and AFib are indistinguishable. This suggests that some ESUS patients have latent pre-clinical fibrotic substrate that could be a future source of arrhythmogenicity. Thus, our work prompts the hypothesis that ESUS patients with fibrotic atria are spared from AFib due to an absence of arrhythmia triggers.

The heart usually beats with a regular rhythm to pump the blood that carries oxygen and nutrients to different organs. Sometimes, alterations in the heart's rhythm known as arrhythmias can occur. Atrial fibrillation, also called AFib, is a type of arrhythmia in which the heart beats rapidly and irregularly, causing abnormal blood-flow that can lead to the formation of blood clots. If one of these blood clots travels to the brain, it can block a blood vessel, causing a stroke. However, many strokes occur without any evidence of AFib. One subset of strokes that are not associated with AFib are embolic strokes of undetermined source (ESUS), which account for 25% of all strokes. By definition ESUS and AFib do not occur together, but both are associated with similar elevated levels of disease-related remodeling (i.e., fibrosis) in the heart tissue, which appears when the heart is injured. Fibrosis impairs the heart's normal electrical activity. Bifulco et al. wanted to determine whether there is some fundamental difference in fibrosis between people with AFib and those who have had an ESUS event. To do this, they used a computational approach to model the geometries and patterns of fibrosis of the hearts of 45 ESUS patients and 45 patients with AFib, essentially producing a virtual version of each patient's heart. Bifulco et al. then applied a virtual pace-maker (working in overdrive mode) to each heart model to determine whether electrical inputs that can lead to AFib had different effects on ESUS and AFib patients. The results showed that the electrical inputs had similar effects in all of the heart models. This led Bifulco et al. to conclude that ESUS and AFib patients have indistinguishable patterns of fibrosis. The key difference is that ESUS patients are missing the trigger to initiate the fibrillation process ­ if atrial fibrosis is the proverbial tinderbox, these triggers are the spark needed to ignite a fire. Further research, including confirmation of Bifulco et al.'s findings in live patients, will be needed to confirm the hypothesis that ESUS patients lack AFib primarily due to an absence of triggers. If this is indeed the case, these findings may make it easier to identify ESUS patients at higher risk for AFib or further strokes. Additionally, a better understanding of fibrosis as a link between stroke and AFib will help clinicians provide better, more personalized treatments, for example guiding whether a patient should take blood thinners or undergo more rigorous cardiac monitoring.

Antagonizing dabigatran by idarucizumab in cases of ischemic stroke or intracranial hemorrhage in Germany-Updated series of 120 cases.

BACKGROUND: Idarucizumab is a monoclonal antibody fragment with high affinity for dabigatran reversing its anticoagulant effects within minutes. Thereby, patients with acute ischemic stroke who are on dabigatran treatment may become eligible for thrombolysis with recombinant tissue-type plasminogen activator (rt-PA). In patients on dabigatran with intracerebral hemorrhage idarucizumab could prevent lesion growth. AIMS: To provide insights into the clinical use of idarucizumab in patients under effective dabigatran anticoagulation presenting with signs of acute ischemic stroke or intracranial hemorrhage. METHODS: Retrospective data collected from German neurological/neurosurgical departments administering idarucizumab following product launch from January 2016 to August 2018 were used. RESULTS: One-hundred and twenty stroke patients received idarucizumab in 61 stroke centers. Eighty patients treated with dabigatran presented with ischemic stroke and 40 patients suffered intracranial bleeding (intracerebral hemorrhage (ICH) in n = 27). In patients receiving intravenous thrombolysis with rt-PA following idarucizumab, 78% showed a median improvement of 7 points in National Institutes of Health Stroke Scale. No bleeding complications were reported. Hematoma growth was observed in 3 out of 27 patients with ICH. Outcome was favorable with a median National Institutes of Health Stroke Scale improvement of 4 points and modified Rankin score 0-3 in 61%. Six out of 40 individuals (15%) with intracranial bleeding died during hospital stay. CONCLUSION: Administration of rt-PA after reversal of dabigatran activity with idarucizumab in case of acute ischemic stroke seems feasible, effective, and safe. In dabigatran-associated intracranial hemorrhage, idarucizumab appears to prevent hematoma growth and to improve outcome.

Left Atrial Appendage Closure With the New Occlutech® Device: First in Man Experience and Neurological Outcome.

AIMS: Percutaneous left atrial appendage closure (LAAC) is a valuable treatment option for stroke prevention in patients with atrial fibrillation and a HAS-BLED-Score ≥3. Determinants of procedural safety events and neurological outcome of the patients with the Occlutech device (OD) are not established yet. METHODS AND RESULTS: Between 2012 and 2016, 30 patients underwent LAAC using the OD. This is a prospective study. Neurological examination and transesophageal echocardiography was performed directly before and after the procedure and after 1, 3, and 12 months. The OC was successfully implanted in 28 of the 30 enrolled patients (93%). Two patients presented a hemodynamic relevant pericardial effusion. A leak <3 mm could be documented direct after implantation in 4 patients. After 3 months, there were only 2/4 patients with persistent LAA leakage with a maximum leakage of <3 mm. The correct position of the device was confirmed in 27/28 patients during 3-month follow-up. In 2 patients, there was a thrombus at the OC. In 12 patients, a transoesophageal echocardiography was performed after 12 months. All patients (12/12) showed a correct placement of the device. None of the patients developed a clinically apparent stroke or died during follow-up. CONCLUSION: In this uncontrolled, nonrandomized study, acute and 3-month follow-up success of LAAC using OD was high. No patient showed significant neurological deficits.

The thermolabile variant of 5,10-methylenetetrahydrofolate reductase is a possible risk factor for amyotrophic lateral sclerosis.

Hyperhomocysteinemia is a risk factor for neurodegeneration, and binding of copper by homocysteine is a putative underlying mechanism. As mutations of the copper-dependent superoxide dismutase are observed in familial ALS, we tested whether genetic variants with influence on homocysteine metabolism are associated with ALS. We compared the frequency of seven variants of genes involved in homocysteine metabolism in 162 patients with sporadic ALS and 162 controls who did not significantly differ in age (t = 1.27, p = 0.205) and gender (χ(2) = 2.48, p = 0.115) using binary regression analysis. Results showed that the variant MTHFR c.677C>T was significantly associated with ALS, i.e. the T-allele was more frequent among patients. Explorative regression analysis revealed that MTHFR c.677C>T was not associated with spinal ALS, but with bulbar onset: CC/CT/TT in patients 0.33/0.51/0.16 versus 0.50/0.44/0.06 in controls; Wald = 5.73, p = 0.017. In addition, DHFR c.594+59del19bp was not associated with spinal, but with bulbar onset: del,del/del,ins/ins,ins in patients 0.16/0.67/0.18 versus 0.11/0.52/0.37 in controls; Wald = 5.02, p = 0.025. The other variants did not show significant associations. In summary, the variants MTHFR c.677C>T and DHFR c.594+59del19bp are involved in homocysteine metabolism. Homocysteine is neurotoxic and binds copper. Thus, the individual variability of homocysteine metabolism, e.g. due to genetic variants, may contribute to the vulnerability of ALS.

Dysphagia due to unilateral infarction in the vascular territory of the anterior insula.

We describe a patient who suddenly developed dysphagia for liquids as the sole manifestation of stroke. Magnetic resonance imaging (MRI) revealed a right-sided infarction of the superior part of the anterior insula and a small portion of the adjacent medial frontal operculum. These findings confirm the role of the anterior insula as a critical area in humans with regard to the origin of dysphagia.

Differential diagnosis in progressive infantile spastic tetraparesis.

Progressive infantile spastic tetraparesis spans a wide spectrum of partially rare differential diagnoses. Based on a clinical example the differential diagnostic thoughts are discussed in detail. Though juvenile motor neuron disease is a rare entity, it has to be kept in mind for differential diagnostics in cases of slowly progressive spastic tetraparesis, especially when a pseudobulbar palsy or distal amyotrophies add to the clinical picture. Electromyography can be helpful for early detection of lower motor neuron involvement. The glutamate antagonist riluzole slows the disease progression, but a causal treatment is not available, yet. Therefore symptomatic treatment of disturbing symptoms like muscle cramps, spasticity, pseudobulbar affect, dyspnea or dysphagia are of major interest.

Two German kindreds with familial amyotrophic lateral sclerosis due to TARDBP mutations.

BACKGROUND: Abnormal neuronal inclusions composed of the transactivation response DNA-binding protein 43 (TDP-43) are characteristic neuropathologic lesions in sporadic and familial forms of amyotrophic lateral sclerosis (ALS). This makes TARDBP, the gene encoding for TDP-43, a candidate for genetic screening in ALS. OBJECTIVES: To investigate the presence and frequency of TARDBP mutations in ALS. DESIGN: Genetic analysis. SETTING: Academic research. PARTICIPANTS: One hundred thirty-four patients with sporadic ALS, 31 patients with familial non-superoxide dismutase 1 gene (non-SOD1) (OMIM 147450) ALS, and 400 healthy control subjects. MAIN OUTCOME MEASURES: We identified 2 missense mutations (G348C and the novel N352S) in TARDBP in 2 small kindreds with a hereditary form of ALS with early spinal onset resulting in fatal respiratory insufficiency without clinical relevant bulbar symptoms or signs of cognitive impairment. RESULTS: The mutations located in the C-terminus of TDP-43 were absent in 400 controls of white race/ethnicity. The novel identified N352S mutation is predicted to increase TDP-43 phosphorylation, while the G348C mutation might interfere with normal TDP-43 function by forming intermolecular disulfide bridges. CONCLUSIONS: Mutations in TARDBP are a rare cause of familial non-SOD1 ALS. The identification of TARDBP mutations provides strong evidence for a direct link between TDP-43 dysfunction and neurodegeneration in ALS.

Diagnosis and treatment of bulbar symptoms in amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is the most common neurodegenerative disease of the motor system. Bulbar symptoms such as dysphagia and dysarthria are frequent features of ALS and can result in reductions in life expectancy and quality of life. These dysfunctions are assessed by clinical examination and by use of instrumented methods such as fiberendoscopic evaluation of swallowing and videofluoroscopy. Laryngospasm, another well-known complication of ALS, commonly comes to light during intubation and extubation procedures in patients undergoing surgery. Laryngeal and pharyngeal complications are treated by use of an array of measures, including body positioning, compensatory techniques, voice and breathing exercises, communication devices, dietary modifications, various safety strategies, and neuropsychological assistance. Meticulous monitoring of clinical symptoms and close cooperation within a multidisciplinary team (physicians, speech and language therapists, occupational therapists, dietitians, caregivers, the patients and their relatives) are vital.

Palliative care and circumstances of dying in German ALS patients using non-invasive ventilation.

Non-invasive ventilation (NIV) is known to improve quality of life and to prolong survival in amyotrophic lateral sclerosis (ALS) patients. However, little is known about the circumstances of dying in ventilated ALS patients. In the light of the debate on legalizing euthanasia it is important to provide empirical data about the process of dying in these patients. In a structured interview, 29 family caregivers of deceased ALS patients were asked about their own and the patient's attitude toward physician-assisted suicide (PAS) and euthanasia, circumstances of dying, and the use of palliative medication. Quantitative and qualitative content analysis was performed on the data. Non-recurring suicidal thoughts were reported by five patients. Three patients and seven relatives had thought about PAS. Seventeen caregivers described the patients' death as "peaceful", while choking was reported in six bulbar patients. In final stages of dying, the general practitioner (GP) was involved in the treatment of 10 patients, with palliative medication including sedatives and opiates being administered in eight cases. In conclusion, in contrast to the Netherlands, where 20% of terminal ALS patients die from PAS or euthanasia, only a small minority of our patients seems to have thought about PAS. The legal situation in Germany (where euthanasia is illegal), a bias due to the selection of NIV patients as well as a high percentage of religious patients and those with good levels of social support from family and friends, might account for this. Most of our patients died peacefully at home from carbon dioxide narcosis, but choking was described in some bulbar patients. Thus, palliative care, especially the use of opiates, anxiolytics and sedatives should be optimized, and the involvement of GP should be strongly encouraged, especially in bulbar patients.

Connective tissue disorders in dissections of the carotid or vertebral arteries.

Dissections of the carotid or vertebral arteries are a significant cause of ischemic stroke. Their etiology includes not only mechanical forces but also underlying arteriopathies such as Ehlers-Danlos syndrome type IV and other connective tissue disorders. Furthermore, dissections often occur spontaneously or after minor trauma in otherwise healthy individuals without clinically evident underlying aberrations. However, in some of these patients ultrastructural connective tissue changes can be detected. An overview of connective tissue disorders associated with dissections of the carotid or vertebral arteries is presented.

Severe sensorimotor neuropathy after intake of highest dosages of vitamin B6.

We illustrate a white caucasian patient with a severe sensorimotor neuropathy due to vitamin B6 hypervitaminosis. The patient used the pendulum to calculate his daily metabolic demands and ingested 9.6g pyridoxine/day. To our knowledge, this is the highest dosage of vitamin B6 administered to humans over prolonged periods of time ever reported in the medical literature. The unique aspect of this case is the muscle weakness and motor findings on electrophysiological testing in what is suggested by the literature to be a pure sensory neuronopathy.

Novel mutation in the ALS2 gene in juvenile amyotrophic lateral sclerosis.

We present a 32-year-old Turkish male with juvenile amyotrophic lateral sclerosis 2 and a previously unrecognized homozygous deletion in exon 4 of the ALS2 gene (553delA). Disease progression is more rapid than in the ALS2 phenotype cases described to date. The patient's consanguineous parents carry the mutation in the heterozygous state as do his two unaffected brothers.