Chorea (Movement Disorders August 2019)

Educational Objectives

The goal of this program is to improve diagnosis and management of movement disorders. After hearing and assimilating this program, the clinician will be better able to:

1. Use history and clinical examination to distinguish chorea from dystonia.
2. List common body regions affected by chorea and associated underlying conditions.
3. Recognize Huntington disease phenocopies.
4. Diagnose antibody-mediated causes of chorea.

Summary

Chorea: Characterized by random, slow, dancelike movements; randomness key feature that distinguishes chorea from dystonia (dystonia features patterns, repetitiveness, abnormal posturing, mirror movements, and sensory tricks); when movements have quick velocity and low amplitude, they may appear jerky and resemble myoclonus; however, jerky movements in quick chorea last longer than brief jerks of myoclonus; tics such as eye blinking and shoulder shrugging sometimes resemble chorea; however, unlike chorea, tics characterized by premonitory urge and suppressibility; stereotypic movements of N-methyl- d -aspartate (NMDA) receptor encephalitis repetitive rather than random.

Chorea athetosis: Athetosis defined as “without fixed position” and may be variant of chorea; athetosis is slow writhing movement that typically involves distal extremities but may affect other areas (eg, face); some experts consider athetosis variant of dystonia; patients with cerebral palsy often demonstrate choreoathetoid movement; therefore, palsy can be difficult to distinguish from chorea.

Etiology: Body distribution of chorea may shed light on diagnosis; hemichorea — typically associated with structural lesions; these may be in thalamic nucleus, basal ganglia, or corona radiata; other conditions associated with hemichorea include nonketotic hyperglycemia, polycythemia vera, and Sydenham chorea; orobuccolingual chorea — may be associated with tardive chorea or acquired hepatocerebral degeneration; orobuccolingual movements also may be caused by dystonia; patients with chorea-acanthocytosis may have prominent protrusion of tongue when eating (feeding dystonia) and self-mutilation (tongue biting); other disorders associated with orobuccolingual dystonia include Lesch-Nyhan syndrome, X-linked dystonia-parkinsonism (Lubag disease), and Wilson disease; forehead chorea — helpful clue for differentiating Huntington disease (HD) from tardive chorea; common in patients with HD but less typical in those with tardive chorea.

General diagnostic approach: Differential diagnosis of chorea extensive; helpful historical information includes demographic data, family history of movement disorders, presence of coexisting dystonia, other neurologic and medical features, and temporal profile; three most important factors temporal profile, age group, and prevalence of chorea in population.

Temporal profile: Patient with acute or subacute course may have acquired or sporadic cause of chorea; genetic cause should be considered in patient with chronic chorea (duration longer than 1 year).

Age group: HD most common cause of genetic chorea in adults, followed by C9orf72 disease and spinocerebellar ataxia (SCA) type 17 (SCA17); in children, most common cause of genetic chorea benign hereditary chorea.

Huntington disease: To support diagnosis of HD, associated clinical features should be present (eg, motor findings such as complex gait [including pelvic tilt related to coexisting dystonia], cognitive impairment, and neuropsychiatric features such as anxiety, irritability, and depression); clinician should look for forehead chorea; impaired initiation of saccades and oculomotor apraxia characteristic abnormalities of eye movements in patients with HD.

Huntington disease phenocopies: Genetic testing and counseling may be indicated; C9orf72 disease — often clinically similar to HD; in European populations, C9orf72 disease more common HD phenocopy than SCA17; key diagnostic clue pyramidal features, which may be seen in patients with C9orf72 disease (eg, brisk reflexes, increased tone, spasticity); other features of C9orf72 include vertical supranuclear gaze palsy; patients with C9orf72 disease who present with chorea may not exhibit frontotemporal dementia or motor neuron disease; SCA17 — characterized by chorea and permanent cognitive and neuropsychiatric features; ataxia and myoclonus may be seen; patients with SCA17 may have rapid progression of cognitive and psychiatric problems; patients usually tested for HD first, then for other genetic disorders if results negative.

Acquired causes of chorea: Include autoimmune encephalitis and movement disorders with acute or subacute onset; chorea associated with autoimmune disorders that do not feature encephalitis; autoimmune disease should be considered in patients with subacute clinical profile (who may be misdiagnosed with HD or other disorders); large variety of antibodies associated with chorea; some patients have multiple antibodies, so clinician should consider ordering entire antibody panel on analyses of serum and cerebrospinal fluid.

Autoimmune disorders: Antibodies classically associated with chorea include those to collapsin response-mediator protein-5 (CRMP5) and cannabinoid receptor; other antibodies may be present (eg, NMDA receptor encephalitis, anti-Hu syndrome, anti-leucine-rich glioma inactivated 1 [LGI1], anti-contactin-associated proteinlike 2 [CASPR2], and anti-Ig-like domain-containing protein 5 [IgLON5]); anti-IgLON5 disease associated with rapid eye movement and non-rapid eye movement parasomnias in 10% of patients, vertical supranuclear gaze palsy, cognitive problems, and chorea; unlike patients with other autoimmune disorders, those with anti-IgLON5 disease typically have longer course of chorea (more than 1 year) and may respond poorly to immunotherapy.

Readings

Hensman Moss DJ, Poulter M, Beck J, et al. C9orf72 expansions are the most common genetic cause of Huntington disease phenocopies. Neurology 2014;82(4):292-299. doi:10.1212/WNL.0000000000000061. Erratum in: Neurology 2014;82(19):1753.

Termsarasab P. Chorea. Continuum (Minneap Minn) 2019;25(4, Movement Disorders).

Disclosures

In adherence to ACCME Standards for Commercial Support, Audio Digest requires all faculty and members of the planning committee to disclose relevant financial relationships within the past 12 months that might create any personal conflicts of interest. Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary business or commercial interest. For this program, the following was disclosed: Dr Termsarasab serves as associate editor of the Journal of Clinical Movement Disorders and on the editorial board of Brain Science Journal. Dr Termsarasab has received personal compensation for speaking engagements for the American Academy of Neurology and Novartis AG and receives publishing royalties from MedLink Neurology.

Unlabeled Use of Products/Investigational Use Disclosure: Dr Termsarasab discusses the unlabeled/investigational use of the current recommended treatments of chorea, none of which are approved by the US Food and Drug Administration except the use of deutetrabenazine for the treatment of chorea associated with Huntington disease and tardive dyskinesia, tetrabenazine for the treatment of chorea associated with Huntington disease, and valbenazine for the treatment of tardive dyskinesia.

To view disclosures of planning committee members with relevant financial relationships, visit: legacy.audio-digest.org/continuumaudio/committee. All other members of the planning committee report nothing to disclose.

The material presented in Continuum Audio has been made available by the AAN for educational purposes only and is not intended to represent the only method or procedure for the medical situations discussed but rather to present an approach, view, statement, or opinion of the speaker(s), which may be helpful to others who face similar situations. Opinions expressed by the speakers are not necessarily those of the AAN, its affiliates, or the publisher. The AAN, its affiliates, and the publisher disclaim any liability to any party for the accuracy, completeness, efficacy, or availability of the material contained in this program (including drug dosages) or for any damages arising out of the use or nonuse of any of the material contained in this program.

Acknowledgements

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 0 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 0 CE contact hours.

Lecture ID:

CA080405

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.