No evidence of perfusion abnormalities in the basal ganglia of a patient with generalized chorea-ballism and polycythaemia vera: analysis using subtraction SPECT co-registered to MRI

Neuropsychiatric disturbance detecting polycythemia vera myelofibrosis: a case report and literature review

Background

Neuropsychiatric disturbances and chorea are less recognized consequences of polycythemia vera (PV), and their role in post-PV myelofibrosis (MF) has not been reported. Clinical features that predict post-PV MF lack specificity.

Case presentation

We describe an elderly patient with PV who developed acute-onset reversible neuropsychiatric disturbances accompanied by generalized chorea and was finally diagnosed with post-PV MF after a bone marrow examination. We also reviewed four cases of late PV associated with neuropsychiatric symptoms since 1966 and analyzed their clinical characteristics and therapeutic effects.

Conclusion

Our case indicates that Janus kinase 2 (JAK2)-related PV is a treatable cause of late-onset chorea and that chorea may herald the deterioration of hematological parameters. Our case provides a clinically specific representation of post-PV MF. Patients with a long course of PV are recommended to undergo bone marrow re-examinations when they present with neuropsychiatric symptoms to achieve an early diagnosis of post-PV MF.

Diagnostic Uncertainties: Chorea

Chorea is a hyperkinetic movement disorder with a multitude of potential etiologies, both acquired and inherited. Although the differential diagnosis for new-onset chorea is extensive, there are often clues in the history, exam, and basic testing that can help to narrow the options. Evaluation for treatable or reversible causes should take priority, as rapid diagnosis can lead to more favorable outcomes. While Huntington's disease is most common genetic cause of chorea, multiple phenocopies also exist and should be considered if Huntington gene testing is negative. The decision of what additional genetic testing to pursue should be based on both clinical and epidemiological factors. The following review provides an overview of the many possible etiologies as well as a practical approach for a patient presenting with new-onset chorea.

Neuropsychiatric Derangement by Polycythemia Vera: A Case Report of an Unexpected Disease Presentation and Review of the Literature

Cerebral infarction as well as other thromboses, headaches, and visual complaints are well-known symptoms of polycythemia vera. However, chorea and neuropsychiatric disturbances are less recognized consequences of this chronic disease. Whereas chorea is a rare but acknowledged symptom of polycythemia vera, neuropsychiatric symptoms have only sporadically been reported. We depict 2 patients with an unusual presentation of polycythemia vera. Our first patient presented with right-sided hemiballism and psychosis, and the second patient had a long diagnostic trajectory of unexplained chorea. In both cases diagnosis of JAK2 positive polycythemia vera was established, and in both cases remarkable recovery occurred after the initiation of phlebotomies. The underlying pathophysiology of these symptoms has not been clearly elucidated. Because of the unfamiliarity of the link between especially neuropsychiatric symptoms and polycythemia, current reported numbers are probably an underestimation. Benefit of treatment appears to be large. We seek to create more awareness among physicians about this phenomenon.

Functional neuroimaging and chorea: a systematic review

Chorea is a hyperkinetic movement disorder consisting of involuntary irregular, flowing movements of the trunk, neck or face. Although Huntington’s disease is the most common cause of chorea in adults, chorea can also result from many other neurodegenerative, metabolic, and autoimmune conditions. While the pathophysiology of these different conditions is quite variable, recent advances in functional imaging have enabled the development of new methods for analysis of brain activity and neuronal dysfunction. In this paper we review the growing body of functional imaging data that has been performed in chorea syndromes and identify particular trends, which can be used to better understand the underlying network changes within the basal ganglia. While it can be challenging to identify whether changes are primary, secondary, or compensatory, identification of these trends can ultimately be useful in diagnostic testing and treatment in many of the conditions that cause chorea.

Movement disorders in systemic diseases

Movement disorders, classically involving dysfunction of the basal ganglia commonly occur in neurodegenerative and structural brain disorders. At times, however, movement disorders can be the initial manifestation of a systemic disease. In this article we discuss the most common movement disorders which may present in infectious, autoimmune, paraneoplastic, metabolic and endocrine diseases. Management often has to be multidisciplinary involving primary care physicians, neurologists, allied health professionals including nurses, occupational therapists and less frequently neurosurgeons. Recognizing and treating the underlying systemic disease is important in order to improve the neurological symptoms.

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.

Left leg apraxia after anterior cerebral artery territory infarction: functional analysis using single-photon emission computed tomography

Left hand apraxia is known as a unique symptom of callosal apraxia, but lower limb symptoms are rarely mentioned. We report a patient who experienced left ideomotor apraxia affecting both the upper and lower limbs after a stroke in the territory of the right anterior cerebral artery. His spontaneous gait was normal, but he was unable to move his left leg intentionally either by verbal command or by imitation. His leg symptoms gradually improved over time. We evaluated the change in cerebral blood flow in this patient using single-photon emission computed tomography. The results showed an increase in blood flow in the posterior corpus callosum; therefore, we suggested that the callosal pathway might contribute to left leg as well as left hand volitional movement.

Reversible abnormal functional neuroimaging presentations in polycythemia vera with chorea

We report a case of polycythemia vera with chorea in which the brain metabolism and dopamine system were investigated using 2-[(18)F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET) and (99m)Tc-labeled tropane dopamine transporter ((99m)Tc-TRODAT-1) single photon emission computed tomography (SPECT). Along with normalization of the hematocrit and clinical symptoms after consecutive phlebotomies, the FDG PET scan and (99m)Tc-TRODAT-1 SPECT images returned towards normal. It is hypothesized that the development of polycythemia chorea is associated with a reversible alteration in the corticobasal ganglia metabolism and disturbed dopaminergic function.

Polycythemia and chorea

Polycythemia vera is a sporadic myeloproliferative disorder of increased red blood cell mass affecting multiple organ systems. Associated thrombosis, hemorrhaging, and hyperviscosity commonly result in neurological manifestations, sometimes in the form of chorea and ballism. Resultant choreiform movements have been mainly described as generalized with orofaciolingual and appendicular muscle involvement, hypotonia, and hyporeflexia. Chorea has also been uncommonly reported as arising from secondary causes of polycythemia; however, the underlying pathophysiology has not been clearly elucidated. Proposed mechanisms for basal ganglia dysfunction include hypoperfusion due to venous stasis, receptor hypersensitivity in a setting of reduced catecholamine levels, and altered platelet dopamine metabolism. Magnetic resonance imaging and single-photon emission computed tomography perfusion studies have failed to reveal an anatomical or physiological basis for polycythemia vera-associated chorea, yet rare pathological examinations of deceased patients have shown signs of cerebral venous thrombosis and perivenous demyelination. Administration of neuroleptics may suppress abnormal choreiform movement; however, effective management of polycythemia vera requires serial venesections in conjunction with chemotherapy. Appropriate treatment may prolong survival to more than 10 years, although chorea may spontaneously remit, re-emerge with resurgence of disease, or continue indefinitely despite maintenance therapy.