Ischemic Stroke with Essential Thrombocythemia: A Case Series

Magnetic resonance imaging features and stroke etiology of ischemic stroke in essential thrombocythemia

BACKGROUND

Various essential thrombocythemia (ET)-related stroke mechanisms have been proposed, including microcirculatory disturbance due to coagulopathy, vasculitis, and embolism due to thrombus formation in large vessels. However, the stroke mechanism in ET remains largely unexplored. The purpose of this study was to evaluate magnetic resonance image (MRI) features of ischemic stroke in ET and determine the potential stroke mechanism.

METHODS

We retrospectively collected data from 21 acute ischemic stroke patients with ET who were admitted to two stroke centers between 2010 and 2023. ET was diagnosed according to the World Health Organization criteria. We evaluated MRI features including the diffusion-weighted image (DWI) lesion pattern, and the presence of hemorrhagic transformation and intracranial artery steno-occlusive lesion, as well as other etiological workup results.

RESULTS

Of 21 patients, 20 exhibited multiple ischemic lesions on DWI, mainly within a single vascular territory. Cortical infarcts were observed in 19 patients. Hemorrhagic transformation occurred in 15 patients. Additionally, 15 patients had intracranial steno-occlusive arteries, which regressed to normal in 11 patients during follow-up. Out of all patients, only 2 had potential causes of stroke other than ET (1 with atrial fibrillation and 1 with intracranial atherosclerotic stenosis). The remaining 19 patients had ET as the only identified potential cause.

CONCLUSIONS

MRI features, including DWI lesion pattern in ischemic stroke patients with ET, suggested embolic etiology despite the absence of major embolic sources. Intra-arterial thrombus appears to be part of the stroke mechanism related to ET and may contribute to ischemic stroke in ET.

Recurrent Stroke with Rapid Development of Intracranial Artery Stenosis and Subsequent Successful Mechanical Thrombectomy in Essential Thrombocythemia

Essential thrombocythemia is a myeloproliferative neoplasm. Ischemic stroke is frequently the first manifestation of essential thrombocythemia. We herein report a patient with JAK2V617 mutation-positive essential thrombocythemia who developed recurrent ischemic stroke with rapid development of intracranial artery stenosis and subsequently underwent successful mechanical thrombectomy. The high JAK2V617F allele burden in our patient (58.4%) may have affected the patient's condition. We discuss similar reports in the literature and the possible pathophysiologic mechanism of large artery involvement in these patients.

JAK2 V617F Mutation and Large Cerebral Artery Disease in Patients with Myeloproliferative Neoplasms

AIM

The aim of the present study was to clarify the association between the Janus kinase 2 (JAK2) V617F mutation and large cerebral artery disease (LCAD) in patients with myeloproliferative neoplasms (MPNs).

METHODS

We retrospectively analysed patients diagnosed with MPNs between June 1992 and June 2022 who underwent brain magnetic resonance imaging. LCAD was defined as extracranial or intracranial large artery stenosis (≥ 50%) or occlusion on magnetic resonance angiography.

RESULTS

A total of 86 patients (47 males; median age, 69 years old) were enrolled in this study. JAK2 V617F mutation was detected in 63 (73.3%) patients and LCAD in 35 (40.7%) patients. Univariate analysis showed that history of ischaemic stroke (LCAD, 62.9% vs. non-LCAD, 11.8%; P＜0.001), JAK2 V617F mutation (91.4% vs. 60.8%, P=0.002), and age ≥ 60 years (85.7% vs. 60.8%, P=0.016) were significantly associated with LCAD. Multiple logistic regression analysis showed that, in addition to ischaemic stroke, age ≥ 60 years and diabetes mellitus, JAK2 V617F mutation (odds ratio 29.2, 95% confidence interval 1.2-709.8, P=0.038) was independently associated with LCAD. LCAD was frequently observed in the intracranial carotid (14/35, 40.0%) and middle cerebral (13/35, 37.1%) arteries.

CONCLUSIONS

This study revealed a significant association between the JAK2 V617F mutation and LCAD in patients with MPNs. This suggests that the JAK2 V617F mutation may promote cerebrovascular atherosclerosis and could be very important in determining therapeutic strategies for patients with not only JAK2 V617F-mutated MPNs but also LCAD-related stroke.

Essential Thrombocythemia and Ischemic Stroke: A Case Series of Five JAK2-Positive Patients

Background and Objectives: Essential thrombocythemia (ET) is a chronic myeloproliferative neoplasm characterized by elevated platelet counts and an increased risk of thrombotic events, including ischemic strokes. Materials and Methods: We conducted a retrospective analysis of data from consecutive ischemic stroke patients with ET between March 2014 and February 2023. Results: This case series describes the clinical presentation, radiological features, and management of five patients with ET-associated ischemic strokes, all harboring the JAK2 mutation. The diverse radiological findings suggest that both large and small vessel diseases may be influenced by the prothrombotic state induced by ET. A significant elevation in platelet count was observed to correlate with the emergence of new acute infarctions in some cases. Conclusions: The study highlights combined use of antiplatelet and cytoreductive therapy in preventing secondary stroke events in patients with ET and JAK2 mutations. The heterogeneity of stroke patterns in this population necessitates a comprehensive understanding of the underlying pathophysiological mechanisms and tailored therapeutic approaches.

Essential thrombocythemia with CALR mutation and recurrent stroke: two case reports and literature review

Cerebrovascular events, especially ischemic stroke, are common complications of essential thrombocythemia (ET). Compared to JAK2V617 F mutation, CALR mutation is considered as a lower risk factor of thrombosis in ET. Until now stroke in ET with CALR mutation has rarely been reported. We retrospectively investigated patients diagnosed with stroke and ET in Xijing hospital of Air Force Medical University, from 2015 to 2021. Clinical characteristics (including medical history, physical and auxiliary examination and prognosis) were recorded and associated literature was reviewed. Among the 19 patients diagnosed with both stroke and ET we retrieved, two cases were positive for CALR mutation. In case 1, a 71-year-old man developed the first ischemic event under the treatment of anagrelide, followed by a hemorrhagic stroke after receiving aspirin and clopidogrel for 4 months. Ischemic stroke reccurred and the neurological function deteriorated progressively. In case 2, a 44-year-old man presented with hypoxic-ischemic encephalopathy due to serious myocardial infarction and subsequent brain imaging indicated three times of ischemic stroke events. The patient gradually got improved through cytoreductive and antiplatelet therapy and rehabilitation. Literature review showed that cerebrovascular event is the most serious neurological complication of ET and may be the presenting symptom. Most of reported cases with ET accompanied by stroke were positive for JAK2 V617 F mutation, but with rare CALR mutation. ET with CALR mutation can cause both hemorrhagic and ischemic stroke. Identification of such rare causes of stroke is of great importance to provide precise and individualized prevention and therapy.

Successful thrombolysis in essential thrombocythemia-related acute ischaemic stroke

Essential thrombocythemia (ET)-related acute ischaemic stroke (AIS) may account for approximately 0.25%-0.5% of all ischaemic strokes. If left undiagnosed and untreated, patients with ET carry an increased risk of recurrent thrombosis involving major organs including the brain. We report an interesting case of a 67-year-old man, who was successfully thrombolysed for AIS resulting from ET. He presented with sudden onset of left-sided hemiparesis with a left-ventricular clot. His subsequent investigations including positive JAK2 V617F mutation confirmed the diagnosis of ET. He made a significant recovery with thrombolysis, anticoagulation, antiplatelet and hydroxyurea. A fear of post-thrombolytic haemorrhagic complications appears the major reason for the lack of reports of thrombolysis in ET-related AIS. Although the diagnosis of ET was confirmed on subsequent investigations, successful thrombolysis in our case provides preliminary evidence that ET-related AIS cases can undergo successful thrombolysis using tenecteplase. To date, ours is only the second case of ET-related AIS being thrombolysed.

Successive development of ischemic stroke and hemorrhagic stroke in a patient with essential thrombocythemia: a case report

Patients with essential thrombocythemia (ET) can experience hemorrhagic or ischemic vascular events. The prevention of these complications is challenging, and the overall risk of vascular events caused by ET is often overlooked. A 34-year-old man was admitted for a 10-day history of weakness and numbness in his right limbs. He had been diagnosed with ET in 2008 but had stopped receiving treatment half a year before admission. Physical examination showed a superficial sense of disturbance in the right limbs and decreased muscle strength in the right upper and lower limbs (4/5). His platelet count (459 × 10⁹/L) was elevated. Magnetic resonance imaging showed acute watershed infarction, and he was treated successfully. However, he was readmitted for headache and left limb weakness 14 months later. A head computed tomography scan revealed spontaneous subdural hemorrhage. He underwent subdural hematoma removal and decompressive craniectomy. Surgery and pathological investigation revealed no venous sinus thrombosis or vascular malformation. His condition improved, and he exhibited a stable condition 1 year after discharge. Successive development of ischemic stroke and spontaneous subdural hemorrhage is rare in a patient with ET. This case suggests that ET is not only a risk factor for stroke but can also cause highly heterogeneous strokes.

Antithrombotic Management in Ischemic Stroke with Essential Thrombocythemia: Current Evidence and Dilemmas

Thrombotic diseases like ischemic stroke are common complications of essential thrombocythemia (ET) due to abnormal megakaryopoiesis and platelet dysfunction. Ischemic stroke in ET can occur as a result of both cerebral arterial and venous thrombosis. Management of ET is aimed at preventing vascular complications including thrombosis. Acute management of ischemic stroke in ET is the same as that in the general population without myeloproliferative disorders. However, an ET patient with ischemic stroke is at high risk for rethrombosis and is therefore additionally managed with cytoreductive therapy and antithrombotic agents. Given abnormal platelet production in ET, there is suboptimal suppression of platelets with the standard recommended dose of aspirin for cardiovascular (CV) prevention. Hence, for optimal CV protection in ET, low-dose aspirin is recommended twice daily in an arterial thrombotic disease like atherothrombotic ischemic stroke in presence of the following risk factors: age >60 years, Janus kinase2 V617F gene mutation, and presence of CV risk factors. In the presence of the same risk factors, concurrent antiplatelet and anticoagulant therapy is suggested for venous thrombosis. However, increased risk of bleeding with dual antithrombotic agents poses a significant challenge in their use in cerebral venous thromboembolism or atrial fibrillation in presence of the above-mentioned risk factors. We discuss these dilemmas regarding antithrombotic management in ischemic stroke in ET in this case-based review of literature in the light of current evidence.

Hemorrhagic stroke associated with essential thrombocythemia: Case report and literature review

Hemorrhagic stroke associated with essential thrombocythemia (ET) is very infrequent. Herein, we report a case of a 33-year-old woman with a 2-year history of ET who developed intracerebral and subarachnoid hemorrhage. Angiography demonstrated severe vessel irregularity in the bilateral cerebral arteries. Molecular genetic testing revealed a calreticulin mutation. To our knowledge, hemorrhagic stroke has been reported in only six other patients with ET, and this is the first report of hemorrhagic stroke in an ET patient with a calreticulin mutation. We review the current literature and discuss the possible underlying mechanisms.

Essential thrombocythemia - a predisponent factor for stroke

The essential thrombocythemia is one of the seven described forms of myeloproliferative neoplasms. It is characterized by megakaryocytic hyperplasia with consequent thrombocytosis maintained in the peripheral blood, favoring the occurrence of thrombo-hemorrhagic phenomena. We present the case of an 81-year-old woman with a history of ischemic stroke in the context of a sustained thrombocytosis, which led to a spinal study and a search for the V617F mutation in the JAK2 gene, which was positive. The patient started cytoreductive therapy with hydroxyurea with favorable current evolution.

Specific mechanisms of subarachnoid hemorrhage accompanied by ischemic stroke in essential thrombocythemia: two case reports and a literature review

BACKGROUND

JAK2 V617F mutation increases the risk of thrombosis, and both ischemic and hemorrhagic strokes can occur in essential thrombocythemia (ET). The mechanisms underlying ischemic stroke in ET are diverse, and hemorrhagic stroke has rarely been reported in ET.

METHODS

Among 627 stroke patients, those identified as having ET were investigated retrospectively. A comprehensive systemic literature search of the PubMed database was also conducted.

RESULTS

Two cases were extracted with the diagnosis of ET who developed SAH and then ischemic stroke. In Case 1, a 47-year-old woman developed SAH in the left high convexity. Eleven hours later, acute cerebellar infarction suddenly developed due to right vertebral artery dissection. In Case 2, a 70-year-old woman developed SAH in the right high convexity. Magnetic resonance angiography showed multifocal stenotic changes in intracranial arteries. Three days later, she developed acute brain infarcts in the right middle cerebral artery territory. Eight weeks later, multifocal stenotic lesions improved. The literature review revealed 5 patients with hemorrhagic stroke and 40 patients with ischemic stroke associated with ET. Age at onset varied, female gender predominated, and the frequency of JAK2 V617F mutation was high. Atherosclerotic vascular risk factors were more common in ischemic stroke, but not in hemorrhagic stroke.

CONCLUSIONS

The current study describes rare cases of SAH accompanied by ischemic stroke secondary to ET along with a review of the current literature, implying specific mechanisms for cerebral artery disorders associated with JAK2 V617F mutation.

Radiological features and outcomes of essential thrombocythemia-related stroke

BACKGROUND

Essential thrombocythemia (ET) is known to be associated with an increased vascular event, but the stroke patterns and prognosis have not been studied.

METHODS

Between January 2013 and December 2017, acute ischemic stroke patients with ET who were admitted to two tertiary hospital stroke centers in Seoul, Korea were included. We retrospectively reviewed their clinical, laboratory and imaging data. Stroke mechanism was determined as ET-only when no atherosclerotic, cardioembolic, or lacunar stroke etiology was demonstrated and as ET-plus group when any specific etiology was combined. Each group was analyzed to ascertain stroke patterns and outcomes.

RESULTS

A total of 26 patients were included, and their mean age was 66 ± 17 years, including 12 female patients. There were 12 ET-only cases and 14 ET-plus cases per stroke mechanism. The ET-plus group included 7 large artery atherosclerosis, 5 small vessel occlusion, and 2 cardioembolic cases. Multiple scattered lesions involving multiple vascular territories were more prevalent in the ET-only group. Poor outcome (modified Rankin scale >2 at discharge) was noted in 13 cases (50.0%), and old age, female sex, prior diagnosis of ET to stroke and low hemoglobin level were associated with poor outcome.

CONCLUSION

ET-related stroke displayed a characteristic infarction pattern, such as multiple embolisms.

Recurrent ischaemic cerebrovascular events as presenting manifestations of myeloproliferative neoplasms

BACKGROUND AND PURPOSE

Myeloproliferative neoplasms (MPNs) - polycythemia vera, essential thrombocythemia and primary myelofibrosis - are associated with increased risk for ischaemic cerebrovascular events (ICVEs). Due to their low prevalence, MPNs often remain undiagnosed as the cause of ICVEs.

METHODS

Case records at the University of Tübingen between 2014 and 2017 were screened to identify patients with MPN-related ICVEs. Clinical features, brain imaging, laboratory findings, applied treatments and neurological outcomes were assessed.

RESULTS

In all, 3318 patients with ICVEs were identified, and amongst them 17 patients with MPN-related ICVEs were included in a retrospective study. In 58% of these patients, ICVEs were the first manifestation of the underlying MPN; 24% presented with transient ischaemic attack and 76% with ischaemic stroke. Potentially concurrent ICVE etiologies were noted in 70% of the patients. The majority (94%) of patients were positive for the JAK2 V617F mutation, whilst in 29% recurrent ICVEs (range two to three) were noted prior to MPN diagnosis. Early MPN diagnosis and management was the only significant prognostic factor for ICVE recurrence (P < 0.001).

DISCUSSION

Evidence is provided that, although rare, MPNs represent an underdiagnosed cause of recurrent ICVEs. High clinical awareness is warranted to identify an underlying MPN in patients presenting with sustained, abnormal blood count findings. Clinical algorithms for prompt MPN diagnosis and initiation of MPN treatment (e.g. cytoreductive therapy, phlebotomy) are required. As MPN management comprises a significant protective factor against ICVE recurrence, induction of MPN treatment should be regarded as an integral component of secondary stroke prevention in MPN-associated ICVEs.

Epigenome-Wide Analyses Identify Two Novel Associations With Recurrent Stroke in the Vitamin Intervention for Stroke Prevention Clinical Trial

DNA methylation, a well-characterized epigenetic modification that is influenced by both environment and genetic variation, has previously been implicated in a number of complex diseases, including cardiovascular disease and stroke. The goal of this study was to evaluate epigenome-wide associations with recurrent stroke and the folate one-carbon metabolism-related trait, plasma homocysteine (hcy). Differential methylation analyses were performed on 473,864 autosomal CpG loci, using Illumina HumanMethylation 450K array data in 180 ischemic stroke cases from the Vitamin Intervention for Stroke Prevention (VISP) clinical trial. Linear regression was used to assess associations between number of strokes prior to VISP enrollment and measures of hcy with degree of methylation (β-values), while logistic regression was used to evaluate recurrent stroke status and incident recurrent stroke associations. All regression analyses were stratified by race. Two differentially methylated CpG sites exceeded epigenome-wide significance (p ≤ 1.055 × 10⁻⁷) for prior number of strokes (PNS) in European Americans. The top locus, cg22812874, was located in the ankyrin repeat and SOCS box containing 10 gene (ASB10; p = 3.4 × 10⁻⁹; β = −0.0308; 95% CI = −0.040, −0.002). Methylation locus cg00340919, located in an intron of the tetratricopeptide repeat domain 37 gene, was also statistically significant (TTC37; p = 8.74 × 10⁻⁸; β = −0.0517; 95% CI = −0.069, −0.034). An additional 138 CpG sites met our threshold for suggestive significance (p ≤ 5 × 10⁻⁵). We evaluated DNA methylation associated with recurrent stroke and hcy phenotypes across the epigenome. Hypermethylation at two CpG sites located in ASB10 and TTC37 was associated with fewer strokes prior to VISP enrollment. Our findings present a foundation for additional epigenome-wide studies, as well as mechanistic studies into epigenetic marks that influence recurrent stroke risk.