Chorea

Original Editor - Muskan Rastogi Top Contributors - Muskan Rastogi, Lucinda hampton, Chelsea Mclene and Cindy John-Chu

Introduction

The word Chorea has Greek origins meaning "to dance". It has a dance-like appearance due to the random and flowing quality of the movement. Chorea is a type of hyperkinetic movement disorder. The involuntary movements flow from one body area to another which cannot be predicted beforehand.

Causes

They are predominantly of 2 types

• Acquired Causes
• Genetic Causes

Acquired Causes of Chorea

Genetic Causes of Chorea

Phenomenological Features

• Randomness
• Flowing Quality
• Parakinesia-Patients blend their chorea-induced movements with their own normal movements.
• Motor impersistence- the patient is unable to perform sustained motor activities.
• Ballism- Variant of chorea which shows large-amplitude flinging movements involving proximal extremities.
• Athetosis-Slow writhing movements involving distal limbs sometimes may be facing.
• Varying velocity of movements-quick velocity and low-amplitude movements accompanied by jerks.

This video displays the dance-like movements performed by a patient.

Diagnosis

The phenomenological features mentioned above are observed to make a diagnosis of chorea.

Differential Diagnosis

Specific diagnosis can be made on the basis of symptoms/clinical features experienced by the patient. These symptoms serve as diagnostic clues and are present as 3 body distributions and other crucial features.

1. On Forehead- Huntington Disease.

Wiggling of the eyebrows or activation of the frontalis muscle is present.

2. On Orobuccolingual region- Tardive Chorea, Acquired Hepatocerebral Degeneration ,Chorea-acanthocytosis, Lesch-Nyhan syndrome, PKAN(dystonia), Lubag Disease(dystonia).

Bonbon sign and problem of inappropriate intake of food is seen which cause biting of lips and tongue.

3. Localized to the contralateral subthalamic nucleus(hemichorea)- Nonketonic hyperglycemia, Polycythemia vera, Sydenham Chorea, Others.

Some disorders which are differentially diagnosed are given in the table below-

Disorder/Symptom	Differentiating Factor from chorea
Dystonia	Predictable patterned movements
Dystonic Tremor	Irregular and jerky does not have a flowing quality like chorea
Myoclonic jerks	Randomness quality of chorea differs the two
Tics	Presence of premonitory urge and suppressibility
Stereotypies	Has stereotypic movement as if the video is running on a repetitive loop
Large amplitude cerebellar outflow tremor	Regular oscillation around the axis and activation of tremor with movements( postural and kinetic components)

Multimodal Management

Chorea requires a Multidisciplinary Approach to be treated.

The team includes

• Psychiatrist
• Physical medicine and Rehabilitation Specialist
• Physical therapist
• Occupational therapist
• Speech therapists
• Geneticist
• Genetic Counselor
• Social worker

Medical Management

1. Dopamine-depleting agents-Tetrabenazine, Deutetrabenazine, Valbenazine.

2. Dopamine D2 receptor-blocking agents-Haloperidol, Clozapine, Olanzapine.

3. Anticonvulsants- Valproic acid, Carbamazepine, Benzodiazepines, Levetiracetam.

4. Anti-glutamatergic agents-Amantadine, Riluzole.

5. Cannabinoids-Nabilone.

6. Deep Brain Stimulation

Physiotherapy Management

The management will be same as of Huntington's Disease. You can read it here.