Paraneoplastic movement disorders: phenomenology, diagnosis, and treatment

Paraneoplastic movement disorder due to suspected metastatic Leiomyosarcoma of tongue: A case report

Paraneoplastic movement disorders, though rare, can be the initial symptoms of malignancies like leiomyosarcoma, as in our case. Clinicians should keep malignancies in their differential diagnosis in cases of unexplained movement abnormalities.

Management of Paraneoplastic Syndromes in the Era of Immune Checkpoint Inhibitors

OPINION STATEMENT

Our understanding of paraneoplastic neurologic syndromes (PNS) has blossomed over the past few decades. Clinicians have access to more robust diagnostic criteria and have a heightened index of suspicion for these disorders. Nonetheless, treatment, which typically includes immunosuppression, and response to treatment, varies. Due to persistent difficulty in making a definitive diagnosis, we favor empiric treatment when a possible diagnosis of PNS is suspected, and other alternative causes have substantially been excluded (e.g., infections, toxic-metabolic derangements, metastasis, or leptomeningeal disease). Treatment of the underlying cancer, if identified, is the first therapeutic step and can prevent disease worsening and in rare cases, can reverse neurologic symptoms. In addition to anti-cancer treatment, first line immunotherapies, which include corticosteroids, intravenous immunoglobulins (IVIG), or plasma exchange (PLEX) are typically used. If partial or no benefit is seen, second line immunotherapeutic agents such as rituximab are considered. Additionally, the severity of the initial presentation and possible risk for relapse influences the use of the latter agents. Symptomatic management is also an important component in our practice and will depend on the syndrome being treated. One of the more novel entities we are facing currently is the management of immune checkpoint (ICI)-induced PNS. In those cases, current American Society of Clinical Oncology (ASCO) guidelines are followed.

Paraneoplastic Neurological Syndromes of the Central Nervous System: Pathophysiology, Diagnosis, and Treatment

Paraneoplastic neurological syndromes (PNS) include any symptomatic and non-metastatic neurological manifestations associated with a neoplasm. PNS associated with antibodies against intracellular antigens, known as "high-risk" antibodies, show frequent association with underlying cancer. PNS associated with antibodies against neural surface antigens, known as "intermediate- or low-risk" antibodies, are less frequently associated with cancer. In this narrative review, we will focus on PNS of the central nervous system (CNS). Clinicians should have a high index of suspicion with acute/subacute encephalopathies to achieve a prompt diagnosis and treatment. PNS of the CNS exhibit a range of overlapping "high-risk" clinical syndromes, including but not limited to latent and overt rapidly progressive cerebellar syndrome, opsoclonus-myoclonus-ataxia syndrome, paraneoplastic (and limbic) encephalitis/encephalomyelitis, and stiff-person spectrum disorders. Some of these phenotypes may also arise from recent anti-cancer treatments, namely immune-checkpoint inhibitors and CAR T-cell therapies, as a consequence of boosting of the immune system against cancer cells. Here, we highlight the clinical features of PNS of the CNS, their associated tumors and antibodies, and the diagnostic and therapeutic strategies. The potential and the advance of this review consists on a broad description on how the field of PNS of the CNS is constantly expanding with newly discovered antibodies and syndromes. Standardized diagnostic criteria and disease biomarkers are fundamental to quickly recognize PNS to allow prompt treatment initiation, thus improving the long-term outcome of these conditions.

Diagnostic Uncertainties in Tremor

The approach and diagnosis of patients with tremor may be challenging for clinicians. According to the most recent consensus statement by the Task Force on Tremor of the International Parkinson Movement Disorder Society, the differentiation between action (i.e., kinetic, postural, intention), resting, and other task- and position-specific tremors is crucial to this goal. In addition, patients with tremor must be carefully examined for other relevant features, including the topography of the tremor, since it can involve different body areas and possibly associate with neurological signs of uncertain significance. Following the characterization of major clinical features, it may be useful to define, whenever possible, a particular tremor syndrome and to narrow down the spectrum of possible etiologies. First, it is important to distinguish between physiological and pathological tremor, and, in the latter case, to differentiate between the underlying pathological conditions. A correct approach to tremor is particularly relevant for appropriate referral, counseling, prognosis definition, and therapeutic management of patients. The purpose of this review is to outline the possible diagnostic uncertainties that may be encountered in clinical practice in the approach to patients with tremor. In addition to an emphasis on a clinical approach, this review discusses the important ancillary role of neurophysiology and innovative technologies, neuroimaging, and genetics in the diagnostic process.

Movement disorders associated with neuronal antibodies: a data-driven approach

Background

Movement disorders can be associated with anti-neuronal antibodies.

Methods

We conducted a systematic review of cases with documented anti-neuronal antibodies in serum and/or cerebrospinal fluid published in PubMed before April 1, 2020. Only patients with at least one movement disorder were included. We used random forests for variable selection and recursive partitioning and regression trees for the creation of a data-driven decision algorithm, integrated with expert’s clinical feedback.

Results

Three hundred and seventy-seven studies met eligibility criteria, totaling 844 patients and 13 antibodies: amphiphysin, GAD, GlyR, mGluR1, ANNA-2/Ri, Yo/PCA-1, Caspr2, NMDAR, LGI-1, CRMP5/CV2, ANNA-1/Hu, IgLON5, and DPPX. Stiffness/rigidity/spasm spectrum symptoms were more frequently associated with amphiphysin, GAD, and GlyR; ataxia with mGluR1, ANNA-2/Ri, Yo/PCA-1, Caspr2, and ANNA-1/Hu; dyskinesia with NMDAR and paroxysmal movement with LGI1; chorea/choreoathetosis with CRMP5/CV2, IgLON5, and NMDAR; myoclonus with GlyR and DPPX; tremors with ANNA2/Ri and anti-DPPX; and parkinsonism with IgLON5 and NMDAR. Data-driven classification analysis determined the following diagnostic predictions (with probability selection): psychiatric symptoms and dyskinesia predicted NMDAR (71% and 87%, respectively); stiffness/rigidity/spasm and ataxia, GAD (67% and 47%, respectively); ataxia and opsoclonus, ANNA-2/Ri (68%); chorea/choreoathetosis, CRMP5/CV2 (41%). These symptoms remained the top predictors in random forests analysis. The integration with an expert opinion analysis refined the precision of the approach. Breast and lung tumors were the most common tumors. On neuroimaging, cerebellar involvement was associated with GAD and Yo/PCA-1; temporal involvement with Caspr2, LGI-1, ANNA-1/Hu.

Conclusion

Selected movement disorders are associated with specific anti-neuronal antibodies. The combination of data-driven and expert opinion approach to the diagnosis may assist early management efforts.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-021-10934-7.

Movement Disorders in Oncology: From Clinical Features to Biomarkers

Background: the study of movement disorders associated with oncological diseases and anticancer treatments highlights the wide range of differential diagnoses that need to be considered. In this context, the role of immune-mediated conditions is increasingly recognized and relevant, as they represent treatable disorders. Methods: we reappraise the phenomenology, pathophysiology, diagnostic testing, and treatment of movement disorders observed in the context of brain tumors, paraneoplastic conditions, and cancer immunotherapy, such as immune-checkpoint inhibitors (ICIs). Results: movement disorders secondary to brain tumors are rare and may manifest with both hyper-/hypokinetic conditions. Paraneoplastic movement disorders are caused by antineuronal antibodies targeting intracellular or neuronal surface antigens, with variable prognosis and response to treatment. ICIs promote antitumor response by the inhibition of the immune checkpoints. They are effective treatments for several malignancies, but they may cause movement disorders through an unchecked immune response. Conclusions: movement disorders due to focal neoplastic brain lesions are rare but should not be missed. Paraneoplastic movement disorders are even rarer, and their clinical-laboratory findings require focused expertise. In addition to their desired effects in cancer treatment, ICIs can induce specific neurological adverse events, sometimes manifesting with movement disorders, which often require a case-by-case, multidisciplinary, approach.

Parkinsonism in viral, paraneoplastic, and autoimmune diseases

Secondary parkinsonism, namely parkinsonism due to causes other than idiopathic neurodegeneration, may have multiple etiologies. Common secondary etiologies of parkinsonism such as drug-induced or vascular etiologies are well documented. Other secondary causes of parkinsonism such as infectious (mainly viral and prion-like diseases), autoimmune (systemic/drug-induced) and paraneoplastic etiologies are rare but are a topic of increasing interest. Older examples from the existing literature demonstrate the intricacies of viral infection from the last pandemic of the 20th century on the development of hypokinetic symptoms experienced in post-encephalitic patients. Viral and prion-like infections are only part of a complex interplay between the body's immune response and aberrant cell cycle perturbations leading to malignancy. In addition to the classic systemic autoimmune diseases (mainly systemic lupus erythematosus - SLE, and Sjögren syndrome), there have been new developments in the context of the current COVID-19 pandemic as well as more prominent use of immunotherapies such as immune checkpoint inhibitors in the treatment of solid tumors. Both of these developments have deepened our understanding of the underlying pathophysiologic process. Increased awareness and understanding of these rarer etiologies of parkinsonism is crucial to the modern diagnostic evaluation of a patient with parkinsonian symptoms as the potential treatment options may differ from the conventional levodopa-based therapeutic regimen of idiopathic Parkinson's disease. This review article aims to give an up-to-date review of the current literature on parkinsonian symptoms, their pathogenesis, diagnostic methods, and available treatment options. Many potential future directions in the field of parkinsonian conditions remain to be explored. This article is part of the Special Issue "Parkinsonism across the spectrum of movement disorders and beyond" edited by Joseph Jankovic, Daniel D. Truong and Matteo Bologna.

Eye movements in demyelinating, autoimmune and metabolic disorders

PURPOSE OF REVIEW

In the last three decades, the use of eye movements and vestibular testing in many neurological disorders has accelerated, primarily because of practical technologic developments. Although the acute vestibular syndrome is a prime example of this progress, more chronic neurologic and systemic disorders have received less attention. We focus here on recent contributions relating vestibular and ocular motor abnormalities in inflammatory, demyelinating, metabolic, and peripheral nervous system disorders RECENT FINDINGS: Vestibular abnormalities have been identified in acute demyelinating neuropathies (AIDP), in novel genetic mutations responsible for CANVAS (cerebellar ataxia, neuropathy vestibular areflexia syndrome), and in other inherited neuropathies (variants of Charcot-Marie-Tooth disease). In addition, there are differentiating characteristics between the most common CNS demyelinating disorders: multiple sclerosis and neuromyelitis optica (NMO). We summarize new information on Vitamin D metabolism in benign paroxysmal positional vertigo (BPPV), followed by a brief review of the vestibular and ocular motor findings in Wernicke's encephalopathy. We conclude with findings in several paraneoplastic/autoimmune disorders.

SUMMARY

This literature review highlights the impact of a careful vestibular and ocular motor evaluation in common neurologic disorder, not only for the initial diagnosis but also for monitoring disease and rehabilitation. A careful examination of eye movements and vestibular function, supplemented with new video techniques to quantify the findings, should be part of the standard neurologic examination.

Movement Disorders in Chronic Kidney Disease - A Descriptive Review

OBJECTIVES

The objective of this study is to describe the mechanism of damage to subcortical structures in chronic kidney disease (CKD) and to describe the range of movement disorders associated with CKD.

MATERIALS AND METHODS

We have reviewed the Medline literature up to January of 2020 using key words movement disorders and chronic kidney disease. The reviewed articles were studied for mechanisms of subcortical damage in CKD as well as type of the reported movements, their frequency and updated treatment.

RESULTS

The search revealed 183 articles most of them dealing with restless legs syndrome. The damage to basal ganglia in CKD resulted from several mechanisms including accumulation of nitro tyrosine caused by reactive oxygen species and action of uremic toxins leading to endothelial damage and dysfunction of blood-brain barrier. Involuntary movements in CKD include restless legs syndrome (RLS), myoclonus, asterixis, dystonia, chorea, tremor, and Parkinsonism.

CONCLUSIONS

Chronic kidney disease can cause several abnormal involuntary movements via damaging basal ganglia and subcortical structures. The most common movement disorders in CKD are RLS, myoclonus and asterixis. Restless legs syndrome and myoclonus when severe, need and respond to treatment. Movement disorders in CKD improve with improvement of kidney function.