Altered properties of amyloidogenic prion protein in genetic Creutzfeldt-Jakob disease with PRNP V180I mutation in response to pentosan polysulfate.

Genetic Creutzfeldt-Jakob disease (gCJD) with V180I prion protein gene (PRNP) mutation shows weaker prion protein (PrP) deposition histologically compared with sporadic CJD, and it is more difficult to detect protease-resistant prion protein in immunoblotting. However, we previously reported the autopsy case of a patient with V180I gCJD who was treated with pentosan polysulfate sodium (PPS); this case had increased protease-resistant PrP deposition. It has been suggested that PPS might reduce protease-resistant PrP; however, the detailed pharmacological and histopathological effects of PPS in humans remain unknown. We examined autopsied human brain tissue from four cases with V180I gCJD that were added to our archives between 2011 and 2021: two cases treated with PPS and two cases without PPS. We conducted a neuropathological assessment, including immunohistochemistry for PrP. We also performed immunoblotting for PrP on homogenate samples from each brain to detect protease-resistant PrP using both a conventional procedure and size-exclusion gel chromatography for the purification of oligomeric PrP. Both PPS-treated cases showed long survival time over 5 years from onset and increased PrP deposition with a characteristic pattern of coarse granular depositions and congophilic PrP microspheres, whereas the cases without PPS showed around 1-year survival from onset and relatively mild neuronal loss and synaptic PrP deposition. Although cortical gliosis seemed similar among all cases, aquaporin 4-expression as a hallmark of astrocytic function was increased predominantly in PPS cases. Immunoblotting of non-PPS cases revealed protease-resistant PrP in the oligomeric fraction only, whereas the PPS-treated cases showed clear signals using conventional procedures and in the oligomeric fraction. These unique biochemical and histopathological changes may reflect the progression of V180I gCJD and its modification by PPS, suggesting the possible existence of toxic PrP-oligomer in the pathophysiology of V180I gCJD and beneficial effects of PPS toward the aggregation and detoxication of toxic PrP-oligomer.

Usefulness of combining CISS and digital subtraction angiography in diagnosis of isolated posterior inferior cerebellar artery dissection.

A 63-year-old man was admitted to our stroke center with brain infarction in the left posterior inferior cerebellar artery (PICA) territory. The initial MRI showed no findings suggestive of arterial dissection, and post-discharge MRI showed no temporal changes. Digital subtraction angiography (DSA) revealed vasodilation of the proximal portion of the PICA but it was uncertain whether dissection was present. Discrepancy between the outer contour seen on constructive interference in steady state (CISS) MRI and the inner contour seen on DSA suggested the presence of intramural hematoma. The patient was diagnosed with brain infarction caused by isolated PICA dissection (iPICAD). Imaging evaluation of combined CISS and DSA may be particularly useful for identification of small iPICAD lesions.

Sequential detection rates of intramural hematoma for diagnosing spontaneous intracranial artery dissection.

BACKGROUND AND PURPOSE: Spontaneous intracranial artery dissection (IAD) can be definitively diagnosed by detecting intramural hematoma (IMH) on arterial wall imaging. However, evidence of a time-dependent natural history for the development of radiological findings is lacking. Therefore, this study aimed to determine when imaging detects IAD. METHODS: We obtained data from our cohort databases between March 2011 and August 2018 on consecutive patients who had definite, probable, or possible IAD based on the multidisciplinary expert consensus criteria. We assessed IMH on initial and follow-up high-resolution three-dimensional T1-weighted imaging (HR-3D-T1WI). We retrospectively investigated the association between IMH detection and days from symptom onset to initial HR-3D-T1WI and compared the IMH detection rate with other definitive diagnostic arterial dissection findings. RESULTS: We analyzed 106 patients (mean age = 51 ± 13 years, 31 women) with at least initial HR-3D-T1WI data. The final diagnoses were definite, probable, and possible IAD in 83, 18, and 5 patients, respectively. IMHs were observed in 63 patients (59%, 95% confidence interval [CI] = 49%-69%). Overall IMH detection rate was 55% (95% CI = 45%-64%), 20% (95% CI = 3%-60%), 40% (95% CI = 21%-64%), and 50% (95% CI = 37%-63%) on the initial HR-3D-T1WI and Days 3, 7, and 13, respectively. Among 68 patients evaluated with digital subtraction angiography and HR-3D-T1WI, IMH was confirmed more frequently than other definitive diagnostic arterial dissection findings. CONCLUSIONS: The overall IMH detection rate on HR-3D-T1WI was >50% and peaked in 1-2 weeks. IMH was a frequently detectable finding for the diagnosis of IAD compared to other radiological findings.

Usefulness of Ultrasonography in the Diagnosis and Follow-up of Extracranial Vertebral Artery Dissection.

Extracranial vertebral artery dissection is a cerebrovascular disease that occurs most commonly in young people. A 32-year-old man experienced sudden cervical pain and was diagnosed with left vertebral artery dissection after arterial changes were identified by ultrasonography. The reduction in the size of an intramural hematoma in the left vertebral artery and in the peak systolic velocity were evaluated over time. Computed tomography, magnetic resonance imaging, and cerebral angiography are generally performed to diagnose and follow-up extracranial vertebral artery dissection; however, carotid ultrasonography has an advantage over these modalities by enabling the simultaneous observation of vascular morphology and hemodynamics.

Oxidized Albumin and Cartilage Acidic Protein-1 as Blood Biomarkers to Predict Ischemic Stroke Outcomes.

Background: There is high demand for blood biomarkers that reflect the therapeutic response or predict the outcomes of patients with acute ischemic stroke (AIS); however, few biomarkers have been evidentially verified to date. This study evaluated two proteins, oxidized albumin (OxHSA) and cartilage acidic protein-1 (CRTAC1), as potential prognostic markers of AIS. Methods: The ratio of OxHSA to normal albumin (%OxHSA) and the level of CRTAC1 in the sera of 74 AIS patients were analyzed on admission (day 0), and at 1 and 7 days after admission. AIS patients were divided into two groups according to their modified Rankin Scale (mRS) at 3 months after discharge: the low-mRS (mRS < 2) group included 48 patients and the high-mRS (mRS ≥ 2) group included 26 patients. The differences in %OxHSA and CRTAC1 between the two groups on days 0, 1, and 7 were evaluated. Results: The mean %OxHSA values of the high-mRS group on days 0, 1, and 7 were significantly higher than those of the low-mRS group (p < 0.05). The CRTAC1 levels continuously increased from day 0 to day 7, and those of the high-mRS group were significantly higher than those of the low-mRS group on day 7 (p < 0.05). Conclusions: These results suggest that higher %OxHSA and CRTAC1 are associated with poor outcomes in AIS patients. An index that combines %OxHSA and CRTAC1 can accurately predict the outcomes of AIS patients.

Transesophageal Echocardiography in Ischemic Stroke With Atrial Fibrillation.

Background To clarify differences in clinical significance of intracardiac thrombi in nonvalvular atrial fibrillation-associated stroke as identified by transesophageal echocardiography (TEE) and transthoracic echocardiography (TTE). Methods and Results Using patient data on nonvalvular atrial fibrillation-associated ischemic stroke between 2011 and 2014 from 15 South Korean stroke centers (n=4841) and 18 Japanese centers (n=1192), implementation rates of TEE/TTE, and detection rates of intracardiac thrombi at each center were correlated. The primary outcome was recurrent ischemic stroke at 1 year after the onset. A total of 5648 patients (median age, 75 years; 2650 women) were analyzed. Intracardiac thrombi were detected in 75 patients (1.3%) overall. Thrombi were detected in 7.8% of patients with TEE (either TEE alone or TEE+TTE: n=679) and in 0.6% of those with TTE alone (n=3572). Thrombus detection rates varied between 0% and 14.3% among centers. As TEE implementation rates at each center increased from 0% to 56.7%, thrombus detection rates increased linearly (detection rate [%]=0.11×TEE rate [%]+1.09 [linear regression], P<0.01). TTE implementation rates (32.3%-100%) were not associated with thrombus detection rates (P=0.53). Intracardiac thrombi were associated with risk of recurrent ischemic stroke overall (adjusted hazard ratio [aHR] 2.35, 95% CI, 1.07-5.16). Thrombus-associated ischemic stroke risk was high in patients with TEE (aHR, 3.13; 95% CI, 1.17-8.35), but not in those with TTE alone (aHR, 0.89; 95% CI, 0.12-6.51). Conclusions Our data suggest clinical relevance of TEE for accurate detection and risk stratification of intracardiac thrombi in nonvalvular atrial fibrillation-associated stroke. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01581502.

Left Atrial Appendage Flow Velocity and Multiple Infarcts in Cryptogenic Stroke.

BACKGROUND: To validate the hypothesis that cryptogenic stroke with multiple infarcts included embolic stroke due to left atrial appendage (LAA) dysfunction, the present retrospective observational study was aimed to clarify the association between LAA flow velocity (LAA-FV) and multiple infarcts in patients with cryptogenic stroke. METHODS: From consecutive patients with cryptogenic stroke admitted to our hospital within 7 days after onset, patients without brain magnetic resonance imaging (MRI) on admission or without transesophageal echocardiography (TEE) during acute hospitalization were excluded, and the remaining patients were enrolled. Multiplicity of fresh infarcts was assessed using diffusion-weighted images from brain MRI. LAA-FV was defined as LAA peak emptying flow velocity on TEE. RESULTS: Of 786 enrolled patients, 522 patients (66%) had a single infarct, and the remaining 264 patients (34%) had multiple infarcts. The percentage of multiple infarcts decreased with increasing quartiles of LAA-FV (p for trend <0.001). The adjusted odds ratio for multiple infarcts decreased with increasing quartiles of LAA-FV (adjusted odds ratio in the fourth quartile, 0.39; 95% confidence interval, 0.25-0.60; compared with the first quartile). LAA-FV as a continuous variable was negatively associated with multiple infarcts (adjusted odds ratio per 10 cm/s, 0.87; 95% confidence interval, 0.81-0.92). CONCLUSIONS: Reduced LAA-FV on TEE was associated with multiple infarcts in patients with cryptogenic stroke. The present findings indicate that cryptogenic stroke with multiple infarcts includes embolic stroke due to LAA dysfunction.

Left Atrial Size and Ischemic Events after Ischemic Stroke or Transient Ischemic Attack in Patients with Nonvalvular Atrial Fibrillation.

BACKGROUND: The present study aimed to clarify the association between left atrial (LA) size and ischemic events after ischemic stroke or transient ischemic attack (TIA) in patients with nonvalvular atrial fibrillation (NVAF). METHODS: Acute ischemic stroke or TIA patients with NVAF were enrolled. LA size was classified into normal LA size, mild LA enlargement (LAE), moderate LAE, and severe LAE. The ischemic event was defined as ischemic stroke, TIA, carotid endarterectomy, carotid artery stenting, acute coronary syndrome or percutaneous coronary intervention, systemic embolism, aortic aneurysm rupture or dissection, peripheral artery disease requiring hospitalization, or venous thromboembolism. RESULTS: A total of 1,043 patients (mean age, 78 years; 450 women) including 1,002 ischemic stroke and 41 TIA were analyzed. Of these, 351 patients (34%) had normal LA size, 298 (29%) had mild LAE, 198 (19%) had moderate LAE, and the remaining 196 (19%) had severe LAE. The median follow-up duration was 2.0 years (interquartile range, 0.9-2.1). During follow-up, 117 patients (11%) developed at least one ischemic event. The incidence rate of total ischemic events increased with increasing LA size. Severe LAE was independently associated with increased risk of ischemic events compared with normal LA size (multivariable-adjusted hazard ratio, 1.75; 95% confidence interval, 1.02-3.00). CONCLUSION: Severe LAE was associated with increased risk of ischemic events after ischemic stroke or TIA in patients with NVAF.

D-dimer level and outcome of minor ischemic stroke with large vessel occlusion.

OBJECTIVE: To determine the predictors of unfavorable outcomes in acute minor ischemic stroke patients with large vessel occlusion. METHODS: The derivation cohort included ischemic stroke patients admitted to a comprehensive stroke center within 7 days after onset with large vessel occlusion and an initial National Institutes of Health Stroke Scale score of 5 or less. An unfavorable outcome was defined as dependency (modified Rankin Scale score of 3 to 6) at 3 months from the onset. The predictive values of factors related to an unfavorable outcome were evaluated. External validation was performed from a stroke registry of a tertiary medical center. RESULTS: In the derivation cohort, 3839 consecutive patients were screened; a total of 130 patients were included. Twenty-four (18%) patients had unfavorable outcomes. In multivariate analysis, D-dimer ≥1900 µg/l (odds ratio (OR) 3.31, 95% confidence interval (CI) 1.14-9.61, p = .028) and age (OR 2.01, 95% CI 1.05-3.86, p = .035) were independently associated with an unfavorable outcome. No significant differences were observed regarding occluded vessel sites. In the validation cohort, 850 consecutive patients were screened; a total of 74 patients were included. D-dimer ≥1900 µg/l (OR 8.78, 95% CI 1.41-54.61, p = .020) was the only factor independently associated with an unfavorable outcome, as in the derivation cohort. CONCLUSIONS: A high D-dimer level on admission could help predict unfavorable outcomes in patients with a minor ischemic stroke with large vessel occlusion.

Atrial Fibrillation-Associated Ischemic Stroke Patients With Prior Anticoagulation Have Higher Risk for Recurrent Stroke.

Background and Purpose- Ischemic stroke associated with nonvalvular atrial fibrillation (NVAF) despite prior anticoagulation may indicate underlying problems that nullify the stroke-preventing effects of oral anticoagulants. We aimed to evaluate the risk for recurrent stroke in patients with NVAF with prior anticoagulation, compared with that in patients without prior anticoagulation. Methods- This study comprised pooled individual patient data on NVAF-associated acute ischemic stroke or transient ischemic attack from 2011 to 2014 arising from the Clinical Research Collaboration for Stroke in Korea (15 South Korean stroke centers) and the Stroke Acute Management With Urgent Risk-Factor Assessment and Improvement-NVAF registry (18 Japanese stroke centers). Data on 4841 eligible patients from the Clinical Research Collaboration for Stroke in Korea registry were pooled with data on all patients (n=1192) in the Stroke Acute Management with Urgent Risk-factor Assessment and Improvement-NVAF registry. The primary outcome was recurrent ischemic stroke. The secondary outcomes were hemorrhagic stroke and all-cause death. Outcome events were captured up to 1 year after the index event. Results- Among the 6033 patients in the full cohort, 5645 patients were analyzed, of whom 1129 patients (20.0%) had received prior anticoagulation. Median age was 75 years (interquartile range, 69-81 years), and 2649 patients (46.9%) were women. Follow-up data of 4617 patient-years (median follow-up 365 days, interquartile range 335-365 days) were available. The cumulative incidence of recurrent ischemic stroke in patients with prior anticoagulation was 5.3% (60/1129), compared with the 2.9% (130/4516) incidence in patients without prior anticoagulation. The risk for recurrent ischemic stroke was higher in patients with prior anticoagulation than in those without (multivariable Cox shared-frailty model, hazard ratio 1.50 [95% CI, 1.02-2.21]). No significant differences in the risks for hemorrhagic stroke and mortality were seen between the 2 groups. Conclusions- The risk for recurrent ischemic stroke may be higher in NVAF-associated stroke patients with prior anticoagulation than in those without prior anticoagulation. Registration- URL: https://www.clinicaltrials.gov; Unique identifier: NCT01581502.

Early Initiation of Direct Oral Anticoagulants After Onset of Stroke and Short- and Long-Term Outcomes of Patients With Nonvalvular Atrial Fibrillation.

Background and Purpose- We aimed to compare outcomes of ischemic stroke patients with nonvalvular atrial fibrillation between earlier and later initiation of direct oral anticoagulants (DOACs) after stroke onset. Methods- From data for 1192 nonvalvular atrial fibrillation patients with acute ischemic stroke or transient ischemic attack in a prospective, multicenter, observational study, patients who started DOACs during acute hospitalization were included and divided into 2 groups according to a median day of DOAC initiation after onset. Outcomes included stroke or systemic embolism, major bleeding, and death at 3 months, as well as those at 2 years. Results- DOACs were initiated during acute hospitalization in 499 patients in median 4 (interquartile range, 2-7) days after onset. Thus, 223 patients (median age, 74 [interquartile range, 68-81] years; 78 women) were assigned to the early group (≤3 days) and 276 patients (median age, 75 [interquartile range, 69-82] years; 101 women) to the late (≥4 days) group. The early group had lower baseline National Institutes of Health Stroke Scale score and smaller infarcts than the late group. The rate at which DOAC administration persisted at 2 years was 85.2% overall, excluding patients who died or were lost to follow-up. Multivariable Cox shared frailty models showed comparable hazards between the groups at 2 years for stroke or systemic embolism (hazard ratio, 0.86 [95% CI, 0.47-1.57]), major bleeding (hazard ratio, 1.39 [95% CI, 0.42-4.60]), and death (hazard ratio, 0.61 [95% CI, 0.28-1.33]). Outcome risks at 3 months also did not significantly differ between the groups. Conclusions- Risks for events including stroke or systemic embolism, major bleeding, and death were comparable whether DOACs were started within 3 days or from 4 days or more after the onset of nonvalvular atrial fibrillation-associated ischemic stroke or transient ischemic attack. Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT01581502.

Tissue Plasminogen Activator for Cortical Embolism Stroke with Magnetic Resonance Perfusion Imaging: A Report of Two Cases.

Computerized tomography (CT) or magnetic resonance imaging (MRI) is indispensable for diagnosing acute ischemic stroke (AIS) patients who are candidates for recombinant tissue plasminogen activator (rt-PA) therapies, but further investigation concerning appropriate selection of therapy following advanced imaging including perfusion imaging has not yet been done. The 2018 AHA guidelines have recommended not to perform excessive time-consuming imaging before rt-PA. Here we describe two cases in which reperfusion therapy was decided based on advanced imaging. The first case was a 70-year-old woman with complaints of total aphasia and right unilateral spatial neglect. Her MRI revealed no apparent high signal area in diffusion-weighted image (DWI), and her magnetic resonance angiography (MRA) showed no large vessel occlusion. Subsequent perfusion-weighted image (PWI) analysis showed a unilateral perfusion deficit in the left middle cerebral artery (MCA) region. The other case was an 88-year-old man with complaints of minor unilateral spatial neglect, right conjugate deviation of the eyes, and dysarthria. His MRI also revealed no apparent high signal area in DWI, and MRA showed slight stenosis in the right middle MCA. Subsequent PWI analysis showed a unilateral perfusion deficit in the right MCA region. In both cases, intravenous rt-PA therapy was administered after the diagnosis of AIS and the patients responded well to the reperfusion therapy. When DWI is performed too early, detecting the ischemic core and differentiating between a diagnosis of stroke and stroke mimics is sometimes difficult. Evaluation of perfusion abnormalities in acute cases can be performed quickly, as shown in these cases. Although rt-PA can be given just by non-contrast CT with no hemorrhage, advanced imaging may be an option to identify difficult-to-diagnose patients who require reperfusion therapy.

Detection of Stenosis Progression in Intracranial Vertebral Artery Dissection Using Carotid Ultrasonography.

BACKGROUND: The purpose of this study was to assess whether carotid ultrasonography indices detect arterial stenosis progression in patients with vertebral artery (VA) dissection. METHODS: This was a retrospective, single-center, observational study that enrolled patients with intracranial VA dissection who were admitted from January 2011 to June 2017. Magnetic resonance angiography (MRA) was done on admission and followed up at a median 20 days after onset (interquartile range [IQR] 9-58 days), and ultrasonography was performed at a median of 22 (interquartile range 7-56) days. Peak systolic velocity (PSV), end-diastolic velocity (EDV), mean velocity (MV), and pulsatility index (PI) were measured by ultrasonography, and the ratio of each follow-up value to the baseline (follow-up/baseline) value was calculated. Two stroke neurologists categorized into 3 groups by morphological changes of the dissected vessel: patients with stenosis progression (progression group: P-group); those with no remarkable change or dilatation improved (stable group: S-group); and those with stenosis regression or dilatation enlargement (enlargement group: E-group). Ultrasonography indices were compared among the groups. RESULTS: Of the 42 patients who were enrolled to this study, 39 patients underwent ultrasonography and MRA on both admission and follow-up. The PI ratio was significantly higher in the P-group than in the S-group (1.96 ± .80 versus .98 ± .44, P = .02) and in the E-group (versus .65 ± .35, P < .01). There were no significant differences in the PSV ratio, EDV ratio, and MV ratio. CONCLUSIONS: In patients with VA dissection, the PI ratio on ultrasonography is a promising index to detect stenosis progression.

Clinical and Radiological Characteristics of Intracranial Artery Dissection Using Recently Proposed Diagnostic Criteria.

BACKGROUND: Data on the clinical and radiological characteristics of intracranial artery dissection (IAD) have remained limited. Our purpose was to reveal the clinical and radiological characteristics of IAD according to diagnostic criteria for IAD as recently reported by a group of international experts. METHODS: Patients were retrospectively enrolled using a prospective single-center stroke registry between 2011 and 2016. Baseline characteristics and radiological findings including conventional magnetic resonance imaging (MRI) sequences, magnetic resonance angiography (MRA), high-resolution 3-dimensional T1-weighted imaging (HR-3D-T1WI), and digital subtraction angiography were reviewed. We performed statistical comparisons to determine which findings from which modalities are useful. RESULTS: We identified 118 patients with suspected artery dissection, with 64 patients (median age, 51 [interquartile range, 45-56) years; 16 women) finally meeting the criteria for definite (n = 47), probable (n = 15), or possible (n = 2) idiopathic IAD. Ischemic stroke alone was found in 31 patients (48%) on admission. There were 36 patients (56%) suffering from hypertension and 39 (61%) with smoking history. The vertebral artery alone was the most affected in 42 patients (66%). Intramural hematoma (IMH) was more frequently detected on HR-3D-T1WI than on conventional MRI/MRA (odds ratio, 4.72; 95% confidence interval, 1.71-13.00). In 54 patients (84%), the modified Rankin Scale score after 3 months was 0-1. CONCLUSIONS: Male dominance and age at IAD onset were similar to previous studies, and more than half had hypertension and smoking history. We confirmed that HR-3D-T1WI is useful for detecting IMH in the diagnostic criteria.

Repeated Paradoxical Brain Infarctions in a Patient on Self-Managed Home Hemodialysis Using a Long-Term Indwelling Catheter.

We describe the case of a 51-year-old Japanese man with an end-stage kidney disease caused by a 30-year history of type 1 diabetes mellitus. The patient had suffered repeated bilateral multiple brain infarctions within a short period of time after the initiation of a self-managed daily home hemodialysis regimen using a long-term indwelling catheter inserted into the right atrium. Despite extensive examinations, we could not find any embolic causes except for the catheter and a patent foramen ovale (PFO). The patient had experienced repeated brain infarctions under antiplatelet and anticoagulation therapies, but suffered no further brain infarctions after the removal of the catheter and the alteration of vascular access from the catheter to an arteriovenous fistula in the forearm. We speculate that the indwelling catheter-associated thrombi or air and the right-to-left shunt through the PFO may have caused the repeated paradoxical brain embolisms in this patient.

[Anticoagulation for patients with non-valvular atrial fibrillation].

Non-valvular atrial fibrillation (NVAF) is the most common cardiac source of emboli in cardioembolic stroke which occupies from 1/4 to 1/3 of acute brain infarction in Japan. Non-vitamin K antagonist oral anticoagulants (NOAC) have been used widely because they are easy to use, their effect in preventing ischemic stroke is higher than or as high as warfarin, their incidence of major hemorrhage is lower than or as low as warfarin, and their incidence of intracranial hemorrhage is much lower than warfarin. However, there seem several issues to address regarding NOAC treatment, such as reversal of anticoagulation, antidotes, monitoring of anticoagulation, rt-PA treatment for acute stroke patients treated with NOACs. In this review, current strategies and issues of anticoagulation for prevention of stroke in NVAF are discussed.