Infarctus cérébraux artériels d’origine hématologique : expérience lausannoise et revue de la littérature

Cerebrovascular manifestations in hematological diseases: an update

Patients with hematological diseases often experience cerebrovascular complications including ischemic stroke, intracerebral and subarachnoid hemorrhage, microbleeds, posterior reversible encephalopathy syndrome, and dural sinus and cerebral vein thrombosis (CVT). In this update, we will review recent advances in the management of cerebrovascular diseases in the context of myeloproliferative neoplasms, leukemias, lymphomas, multiple myeloma, POEMS, paroxysmal nocturnal hemoglobinuria (PNH), thrombotic thrombocytopenic purpura (TTP), and sickle-cell disease. In acute ischemic stroke associated with hematological diseases, thrombectomy can in general be applied if there is a large vessel occlusion. Intravenous thrombolysis can be used in myeloproliferative neoplasms and sickle-cell anemia, but in other diseases, a case-by-case evaluation of the bleeding risks is mandatory. Patients with sickle-cell disease and acute stroke need very often to be transfused. In PNH, acute ischemic stroke patients must be anticoagulated. Most patients with CVT can be treated with low-molecular weight heparin (LMWH) acutely, even those with leukemias. Prevention of recurrence of cerebral thrombotic events depends on the control of the underlying disease, combined in some conditions with antithrombotic drugs. The recent introduction of specific monoclonal antibodies in the treatment of PHN and TTP has dramatically reduced the risk of arterial and venous thrombosis.

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.

Chronic myeloproliferative diseases

The chronic myeloproliferative disorders are a group of diseases in which there is an increased proliferation of one or more subtypes of myeloid cells; they include essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (PMF). In ET and PV the main neurologic manifestations are headaches, dizziness and macro- and microvascular, both venous and arterial, thrombosis and intracranial hemorrhages. Paresthesias and chorea also occur in PV. In PMF neurologic complications are very rare and consist predominantly of spinal cord compression by extramedullary hematopoiesis tissue.

Ischaemic stroke and essential thrombocythemia: a series of 14 cases

BACKGROUND

Essential thrombocythemia (ET) is considered as a rare cause of stroke, partially because of difficulties to identify it when platelet count is not greatly elevated. However, early detection of ET is important because, without adapted treatment, recurrent thromboses are frequent.

METHOD

We collected, retrospectively, data from 14 cases of stroke patients with ET. Clinical characteristics, ischaemic stroke, laboratory data (platelet and leucocyte count, haemoglobin, JAK2 V617F mutation, culture of haematopoietic progenitors) and treatment were reviewed. Every patient has been interviewed by phone to evaluate outcome.

RESULTS

The population consisted of nine women and five men with ages ranging from 40 to 87 years. Most of the patients (12) had atherosclerotic risk factors and two presented a thrombus in the internal carotid. ET was diagnosed early after the onset of stroke except in two patients. The platelet count was under 600*10(9) /L for five patients. Mutation JAK2 V617F was found for eight patients. Thirteen patients were treated with an association between antiplatelet and cytoreductive treatment and did not present further thrombosis. Median follow-up is 2.8 years.

CONCLUSION

These cases emphasize the problems of diagnosing ET at the onset of the stroke. Complete blood count has to be carefully read and ET can be suspected even if platelet count is not greatly increased. Diagnosis must be confirmed by haematologist to initiate appropriate treatment.

Stroke and cancer: a review

Stroke is a disabling disease and can add to the burden of patients already suffering from cancer. Several major mechanisms of stroke exist in cancer patients, which can be directly tumour related, because of coagulation disorders, infections, and therapy related. Stroke can also occur as the first sign of cancer, or lead to its detection. The classical literature suggests that stroke occurs more frequently in cancer patients than in the average population. More recent studies report a very similar incidence between cancer and non-cancer patients. However, there are several cancer-specific types and causes of stroke in cancer patients, which need to be considered in each patient. This review classifies stroke into ischaemic, haemorrhagic, cerebral venous thrombosis and other rarer types of cerebrovascular disease. Its aim is to identify the types of stroke most frequently associated with cancer, and give a practical view on the most common and most specific types of stroke. The diagnosis of the cause of stroke in cancer patients is crucial for treatment and prevention. Management of different stroke types will be briefly discussed.