Mouvements choréo-athétosiques et syndrome anti-Hu

[A case of anti-SRY-Related HMG-Box Gene 1 (SOX1) antibody-positive chorea]

A 77-year-old man with a history of lung cancer at the age of 71 developed involuntary right leg movement for a month. Neurological examination revealed a right-sided hemi-chorea. Autoimmune disease was suspected owing to the presence of oligoclonal bands and the elevated IgG-index in the cerebrospinal fluid. We detected anti-SRY-Related HMG-Box Gene 1 (SOX1) antibodies, known to be serological markers of Lambert-Eaton syndrome with small cell lung cancer, but not tumors. The results of tests for antiphospholipid, anti-LGI1, and anti-CASPR2 antibodies associated with non-paraneoplastic autoimmune chorea were all negative. This is the first suggestive case of autoimmune chorea in which anti-SOX1 antibodies were detected.

Autoimmune paraneoplastic syndromes associated to lung cancer: A systematic review of the literature: Part 3: Neurological paraneoplastic syndromes, involving the central nervous system

The development of new immune treatment in oncology and particularly for lung cancer may induce new complications, particularly activation or reactivation of auto-immune diseases. In this context, a systematic review on the auto-immune paraneoplastic syndromes that can complicate lung cancer appears useful. This article is the third of a series of five and deals mainly with neurological paraneoplastic syndromes involving the central nervous system.

Paraneoplastic Choreoathetosis in a Patient with Small Cell Lung Carcinoma and Anti-CRMP5/CV2: A Case Report

Introduction

The occurrence of more or less monosymptomatic paraneoplastic choreoathetosis associated with anti-CRMP5/CV2 antibodies is rare. Typically, such autoantibodies are associated with a more classical syndrome – paraneoplastic encephalomyelitis. Frequently, small cell lung carcinoma (SCLC) is the related neoplastic finding.

Case Report

We present a 71-year-old woman who developed visual symptoms with papilledema and chorea. Anti-CRMP5/CV2 antibodies were a feature of both the serum and cerebrospinal fluid. Although SCLC was suspected already at the time of the initial examinations, no signs of primary or metastatic tumors were revealed on chest X-ray, MRI or whole-body PET scan. EEG and bronchoscopy were also unremarkable. However, 6 months after the onset, a repeated PET scan and subsequent bronchoscopic biopsy revealed SCLC. In spite of chemotherapy, the SCLC progressed, and the patient died 14 months after the onset of the symptoms.

Conclusion

We report paraneoplastic choreoathetosis associated with anti-CRMP5/CV2 antibodies. Such published case histories are rare. Although expected, we did not find any reduced signal intensity at the basal ganglia on the T1-weighted or increased intensity on the T2-weighted MRI scans.

Update on the Non-Huntington's Disease Choreas with Comments on the Current Nomenclature

CHOREA CAN BE CAUSED BY A MULTITUDE OF ETIOLOGIES: neurodegenerative, pharmacological, structural, metabolic, and others. In absence of other apparent causes, exclusion of Huntington's disease is often a first step in the diagnostic process. There are a number of neurodegenerative disorders whose genetic etiology has been identified in the past decade. Molecular diagnosis has enabled genetic identification of disorder subtypes which were previously grouped together, such as the neurodegeneration with brain iron accumulation disorders and the neuroacanthocytosis syndromes, as well as identification of phenotypic outliers for recognized disorders. Correct molecular diagnosis is essential for genetic counseling and, hopefully, ultimately genetic therapies. In addition, there has recently been recognition of other disorders which can mimic neurodegenerative disorders, including paraneoplastic and prion disorders. This article focuses upon recent developments in the field but is not intended to provide an exhaustive review of all causes of chorea, which is available elsewhere. I also discuss the nomenclature of these disorders which has become somewhat unwieldy, but may ultimately be refined by association with the causative gene.

Differential diagnosis of chorea

Chorea is a common movement disorder that can be caused by a large variety of structural, neurochemical (including pharmacologic), or metabolic disturbances to basal ganglia function, indicating the vulnerability of this brain region. The diagnosis is rarely indicated by the simple phenotypic appearance of chorea, and can be challenging, with many patients remaining undiagnosed. Clues to diagnosis may be found in the patient's family or medical history, on neurologic examination, or upon laboratory testing and neuroimaging. Increasingly, advances in genetic medicine are identifying new disorders and expanding the phenotype of recognized conditions. Although most therapies at present are supportive, correct diagnosis is essential for appropriate genetic counseling, and ultimately, for future molecular therapies.

Huntington's disease look-alikes

Huntington's disease (HD) is caused by a triplet repeat expansion in the IT15 gene on chromosome 4 encoding huntingtin. Gene mutations are found in about 99% of cases, with symptoms and signs suggestive of HD. This implies the existence of other causes of this syndrome, and, in recent years, several other distinct genetic disorders have been identified that can present with a clinical picture indistinguishable from HD, termed HD-like (HDL) syndromes. So far, four genes associated with HDL syndromes have been identified, including the prion protein gene (HDL1), the junctophilin 3 gene (HDL2) and, the gene encoding the TATA box-binding protein (HDL4). In addition, a single family with a recessively inherited HD phenocopy, the exact genetic basis of which is currently unknown (HDL3), has been described. These disorders, however, account for only a small proportion of HDL cases, and the list of HDL genes and conditions is set to grow. In this article, we review the currently identified HD phenocopy disorders and discuss clinical clues to facilitate further investigations. We will concentrate on the four so-called HDL syndromes mentioned above. Other genetic choreatic syndromes such as dentatorubral-pallidoluysian atrophy, neuroferritinopathy, pantothenate kinase-associated neurodegeneration, and chorea-acanthocytosis are also briefly discussed.

[A case of lung adenocarcinoma presenting with chorea with bilateral basal ganglial lesions on MRI]

The patient, a 63-year-old man, experienced the subacute onset of chorea, for which his family doctor prescribed oral haloperidol. However, the involuntary movements gradually worsened, and the patient was referred and admitted. High-signal lesions were seen in the caudate nucleus, putamen and globus pallidus bilaterally on MRI T2-weighted and FLAIR images. Chest CT, FDG-PET and tissue biopsies also revealed that the patient had lung adenocarcinoma with multiple lymph node metastases. The patient was diagnosed as having paraneoplastic chorea associated with primary lung adenocarcinoma. Antineuronal antibodies, such as anti-CRMP-5 and anti-Yo antibodies, were absent. The patient received steroid pulse therapy, oral prednisolone therapy, and concurrent radiochemotherapy. Chorea and high-signal lesions in the corpus striatum bilaterally on MRI improved quickly, and the mediastinal lymph node swelling also improved. The patient has been stable for 3 years since the onset of his symptoms. As the prognosis of paraneoplastic chorea is relatively favorable in some patients, it should be considered in the differential diagnosis of patients with chorea.

Paraneoplastic movement disorders

Neurologic paraneoplastic syndromes (NPSs) result from damage to the nervous system due to the remote effects of cancer not related to metastasis, infection, or metabolic derangements. NPSs are rare, affecting 1 in 10,000 patients with cancer. Pathogenesis is likely related to the immune mechanisms: normal neural tissue is mistakenly attacked due to the similarity in the onconeural antigens expressed by the tumor cells. Among the various "classic" and other NPSs, this review focuses on paraneoplastic movement disorders, including ataxia due to cerebellar degeneration, stiff-person syndrome, opsoclonus-myoclonus syndrome, chorea, parkinsonism, and tremor. The recently described syndrome of paraneoplastic anti-N-methyl-D-aspartate receptor encephalitis is also included, given that these patients have complex movements such as stereotypies and dyskinesias in addition to psychiatric symptoms, altered sensorium, and other neurologic signs. Although variable, treatment and prognosis of NPSs rely heavily on treatment of the underlying malignancy and immunotherapy.

Seminar on choreas

Chorea is one of the major types of involuntary movement disorders originating from dysfunctional neuronal networks interconnecting the basal ganglia and frontal cortical motor areas. The syndrome is characterised by a continuous flow of random, brief, involuntary muscle contractions and can result from a wide variety of causes. Diagnostic work-up can be straightforward in patients with a positive family history of Huntington's disease or acute-onset hemichorea in patients with lacunar stroke, but it can be a challenging and complex task in rare autoimmune or genetic choreas. Principles of management focus on establishing an aetiological classification and, if possible, removal of the cause. Preventive strategies may be possible in Huntington's disease where genetic counselling plays a major part. In this review we summarise the current understanding of the neuroanatomy and pathophysiology of chorea, its major aetiological classes, and principles of diagnostic work-up and management.

Chorea: non-genetic causes

PURPOSE OF REVIEW

The aim of this article is to review the literature on the non-genetic causes of chorea. The differential diagnosis of the large number of causes of sporadic chorea is often a challenging task. Interest has also been growing in the possibility that the mechanism responsible for Sydenham's chorea plays a role in the pathogeneis of other neuropsychiatric disorders.

RECENT FINDINGS

Stroke is the main cause of sporadic chorea. Sydenham's chorea shares clinical features with tic disorders, such as obsessive-compulsive disorder and attention deficit hyperactivity disorder. However, there are unequivocal differences between Sydenham's chorea and Tourette's syndrome. There is initial evidence suggesting the beneficial effect of immunosuppression in Sydenham's chorea. Other autoimmune causes of chorea include systemic lupus erythematosus as well as paraneoplastic syndromes. The growing list of drugs associated with chorea include lamotrigine, methadone and lithium. Among infectious agents, HIV is the leading reported cause of chorea.

SUMMARY

Patients with sporadic chorea require a thorough work up because numerous causes can lead to this condition. It remains unconfirmed whether the pathogenic mechanisms of Sydenham's chorea are responsible for other conditions such as isolated obsessive-compulsive disorder or Tourette's syndrome. Drugs and infectious agents, especially HIV, are often implicated in the causes of chorea.