Movement Disorder Medicines
Anxiety-Antidepressant Medications
Antidepressant Adverse Effects
Warnings~Adolescents Under 25
Sertraline ~Zoloft
Anti-psychotic Medications
Prozac, Luvox, Paxil, Zoloft & Celexa
Olanzipine & Risperidone and blood tests
Cutting Prescriptions
Sites That Help the Medicine Go Down
Vitamins & Minerals
Why Certain Symptoms Occur In HD
Tests Commonly Used -Neuropsychological Examination
Symptom vs Medication
Speech & Swallowing Difficulties~Lynn Rhodes
Swallowing Problem Warning Signs
Swallowing Tests
Nutrition and HD~Anna Gaba (Recipes)
HD & Diet~HSA Fact Sheet 7
HD~Swallowing & Nutrition
Weight Gain
5 Levels Difficulty In Swallowing
Feeding Tube~Advanced Stages of HD
Feeding Tube~Jean Miller
One more word on feeding tubes
PEG Tubes and baby foods
Feeding Tubes-More Info
HD~Falling/Safety Issues
HD~Cognitive/Decision Making/Impulsivity
Cognitive-Short Tips
Denial of HD
HD~Irritability/Temper Outbursts
Managing behavioral problems
Depression - Treatment Resistant Patient
HD~Mania, Obsessive Disorders
HD~Hallucinations & Psychosis
HD~Rigidity, Spasticity, and Dystonia
Adaptive Products
Teen Suicide~Let's Talk Facts
Stress Explained-Easy/Fun Format
How To Help Someone Chronically Ill
Legal Planning for Incapacity
Out-of-Home Care Options FAQ
Preparing for Emergencies

The term chorea comes from the Latin word choreus, which means dancing.
Chorea has been defined by the ad hoc Committee on Classification of the
World Federation of Neurology as "a state of excessive, spontaneous movements,
irregularly timed, non-repetitive, randomly distributed and abrupt in character.
These movements may vary in severity from restlessness with mild intermittent
exaggeration of gesture and expression, fidgeting movements of the hands,
unstable dance-like gait to a continuous flow of disabling, violent movements."
Chorea involves proximal as well as distal muscles. In most patients, normal tone is
noted, but in some instances, hypotonia is present. In a busy movement disorder
center, levodopa-induced chorea is the most common movement disorder, followed by Huntington disease (HD).
Ballism, derived from the Greek word meaning "to throw," has been defined as
"continuous, violent, coordinated involuntary activity involving the axial and proximal appendicular musculature such that the limbs are flung about." This movement disorder most often involves only one side of the body (ie, hemiballism[us]).
Occasionally, bilateral movements occur (ie, biballism or paraballism). Many patients with hemiballism have chorei-form movements and vice versa, and hemiballism often evolves into hemi-chorea. Currently, ballism should be viewed as a severe form of chorea.
A simple model of basal ganglia function states that dopaminergic and GABAergic
impulses from the substantia nigra and motor cortex, respectively, are funneled
through the pallidum into the motor thalamus and motor cortex. These impulses are modulated in the striatum via 2 segregated, parallel, direct and indirect loops through the medial pallidum and lateral pallidum/subthalamic nucleus.
Subthalamic nucleus activity drives the medial pallidum to inhibit cortex-mediated impulses, thereby inducing parkinsonism. Absent subthalamic nucleus inhibition enhances motor activity
through the motor thalamus, resulting in abnormal involuntary movements such as
dystonia, chorea, and tics. A classical example of loss of subthalamic inhibitory drive is ballism.
The choreatic syndrome that has been studied the most is Huntington chorea;
therefore, the pathophysiology of HD as it applies to chorea will be the focus of the
discussion that follows.
Dopaminergic mechanism
In Huntington chorea, the content of striatal dopamine is normal, indicating that the major pathological alterations lay in the surviving, but diseased, medium-sized, spiny, striatal dopaminergic neurons.
Pharmacologic agents that either deplete dopamine (eg, reserpine, tetrabenazine) or block dopamine receptors (eg, neuroleptic medications) improve chorea, giving further support to this observation. Since drugs that decrease the striatal content of dopamine improve chorea, increasing the amount of dopamine worsens chorea, such as the levodopa-induced chorea seen in Parkinson disease (PD).
Cholinergic mechanism
The concept that a critical striatal balance between acetylcholine (Ach) and dopamine is essential for normal striatal function received its greatest acceptance in the understanding of PD. In the early phases of PD, anticholinergic medications are used commonly, especially when tremor is the predominant symptom. Other PD symptoms, such as bradykinesia and rigidity, may improve as well.
Development of chorea in patients treated with anticholinergic medications such as
trihexyphenidyl is a common clinical observation. Furthermore, intravenous administration of physostigmine (a centrally acting anticholinesterase) can reduce chorea temporarily. Similarly, anticholinergic-induced chorea can be overcome promptly by administration of
In the basal ganglia of patients with HD is a patchy reduction of choline acetyltransferase, the enzyme that catalyzes the synthesis of ACh. A marked reduction of muscarinic cholinergic receptor sites also has been reported. These 2 observations could explain the
variability of the response to physo-stigmine and the limited efficacy of Ach precursors, such as choline and lecithin.
Serotonergic mechanism
Manipulation of striatal serotonin may play a role in the genesis of many abnormal movements.
Selective serotonin reuptake inhibitors such as fluoxetine may induce or aggravate parkinsonism, akinesia, myoclonus, or tremor. The role of serotonin (5-hydroxytriptamine [5-HT]) in choreiform movements is less clear.
The striatum has a relatively high concentration of serotonin. Pharmacologic attempts to either stimulate or inhibit serotonin receptors in Huntington chorea have shown no effect, indicating that the contribution of serotonin in the patho-genesis of chorea is limited.
GABAergic mechanism
The most consistent biochemical lesion in Huntington chorea appears to be a loss of
neurons in the basal ganglia that synthesize and contain GABA. The significance of this remains unknown. A variety of pharmacologic techniques to increase CNS GABA levels have been attempted; however, no benefits have been obtained.
Substance P and somatostatin
Substance P has been shown to be markedly decreased in HD, while somatostatin is increased. The significance of this remains unknown.
This movement disorder usually involves only one side of the body (ie, hemiballism).
Hemiballism usually is attributed to lesions of the contralateral subthalamic nucleus, although infarction in the caudate, striatum, lenticular nucleus, or thalamus also has been associated with hemiballism.
Lesions of the subthalamic nucleus cause contralateral hemiballism-hemichorea by
reducing the normal excitatory drive from the subthalamic nucleus to the internal segment of the globus pallidus.
This reduces the inhibitory output of the globus pallidus on the thalamus, and this disinhibitiongives rise to excessive excitatory drive to the cortex,
which is expressed as contralateral hyperkinetic movements. However, this disorder often appears in the absence of a lesion in the subthalamic nucleus.
Klawans et al suggested that increased dopaminergic transmission might play a role in the pathophysiology of this disorder. This hypothesis is supported by the observation that dopamine-receptor blockers and catecholamine-depleting agents often improve hemiballism.
While hemiballism and hemichorea are distinguishable on the basis of type
and distribution of movements, they represent 2 different symptoms on a spectrum of the same disease process. Why one patient with basal ganglia dysfunction develops hemiballism and another with similar pathologic change develops hemichorea is unknown.

In the US: Although no data are available regarding the incidence of chorea, the incidence of several entities in which chorea is the main clinical feature  is well known.
  • HD is an autosomal dominant, neurodegenerative disorder in
    which the defective gene is located on the short arm of  chromosome 4. The estimated prevalence of HD in the United States is 5-10 per 100,000 people.
  • Wilson disease is an autosomal recessive, multisystem disease
    with a gene linked to the esterase D locus on chromosome 13. Although the gene prevalence (heterozygous carriers who inherited only 1 abnormal gene) has been estimated to be as high as 1%, the disease prevalence is only 30 per 1,000,000.
  • Benign hereditary chorea, a fairly rare disorder in which most of
    the pedigrees have clearly demonstrated dominant inheritance, has an incidence of approximately 1 per 500,000.
  • George Huntington first described Huntington disease ransmission in 1872 in successive generations of natives of Long Island, New York.  All affected individuals descended from ancestors who had emigrated from East Anglia to the New World in 1649. This disorder now is
    dispersed widely around the globe.
  • HD is best known in Caucasian populations. All cases of the disorder have probably occurred from the lineage originating in East Anglia.
  • Also, informative genotypes were obtained from a vast family lineage carrying the gene; they are located in and around Lake Maracaibo, Venezuela.
  • Chorea may commence at any age. In children, postpump chorea and infectious, inflammatory, and striatal lesions may account for many cases.
  • About 10% of patients with HD have onset of the disease when they are younger than 20 years, about 6% when they are younger than 21 years, and about 3% when they are
    younger than 15 years, but the typical peak age at onset is in the fourth and fifth decades of life.
  • Cases have been recognized in patients younger than 5 years. Patients with early onset usually inherited the disease from their father, while patients with later onset are more likely to have inherited the gene from their mother. The relatively low rate of expression in childhood is succeeded by a virtual exponential upsweep in
    the rate of appearance through the second and third decades of life to reach a plateau that is sustained from the fourth to the seventh decades. Although 27% of cases are first recognized in patients older than 50 years, most of the cases are
    documented in patients younger than 60 years. Onset has been
    recorded as late as the eighth decade.
  • Neuroacanthocytosis, perhaps the most common form of hereditary chorea, usually manifests clinically in the third and fourth decade (range is 8-62 years). It should be
    differentiated from late-onset HD through careful pedigree analysis and neurogenetic testing.
  • Senile chorea is a condition that manifests gradually in late
    middle life.

  • In general, on the basis of age of onset, benign hereditary chorea may be divided into 3 types: (1) early infancy, (2) at about 1 year of age, and (3) during late childhood or
    adolescence. The most common age of onset is about 1 year, when the child begins to walk.
Patients suffering from chorea may not be initially aware of the abnormal movements, as the abnormalities may be subtle.
Patients can suppress the chorea temporarily and frequently "camouflage" some of the movements by incorporating them into semipurposeful activities (ie, parakinesia).
The inability to maintain voluntary contraction (ie, motor impersistence), as seen during manual grip (milkmaid grip) tests or tongue protrusion, is a character-istic feature of chorea and results in dropping objects and clumsiness. Muscle stretch reflexes are often "hung-up" and pendular.
In severely affected patients, a peculiar dancelike gait may be noted. Depending on the underlying cause of the chorea, other motor symptoms include dysarthria, dysphagia, postural instability, ataxia, dystonia, and myoclonus. A brief discussion of the clinical manifestations of the most common choreatic diseases is presented here.
Huntington disease
  • Penetrance of HD is 100%. Expression is highly variable, both with respect to clinical manifestations and age of onset. When the disorder emerges early, particularly in patients younger than 20 years, it is most likely to run a rapid course with grave disability due to cognitive decline.
  • The "Westphal variant," the rigid dystonic disorder, may be accompanied by seizures and even myoclonus. It is encountered principally among those with childhood onset. By contrast, when the disorder appears late in life, the
    cardinal manifestation is chorea.
  • The insidious onset of clumsiness and adventitious movements may be attributed wrongly to simple
    nervousness. Although chorea and other motor disabilities are the most readily recognized, they may be neither the earliest to appear nor the most disabling manifestation
    of HD.
  • Psychological disturbances and personality change are the initial manifestations in over 50% of affected persons. Symptoms consistent with a depressive state are the most frequent.
  • Duration of illness from onset to death is about 15 years in the case of adult HD and 8-10 years for the juvenile variant.
Wilson disease
  • The clinical features are age dependent. In children,
    the disease is manifested initially by progressive dystonia, rigidity and dysarthria, and hepatic dysfunction, whereas in adults psychiatric symptoms, tremor, and
    dysarthria usually predominate
Wilson's Disease continued
  • Since Kayser-Fleischer rings are almost always present when neurological symptoms are present, slit-lamp examination of the cornea needs to be carried out to be certain that Wilson disease is excluded in a patient with chorea beginning in childhood or young adulthood.
    In patients with chorea and a negative slit-lamp examination, serum copper and ceruloplasmin along with a 24-hour copper urine excretion need to be measured
Symptoms usually begin with lip and tongue biting (often causing self-injury), orolingual dystonia, motor and phonic tics, generalized chorea, parkinsonism, and seizures. Patients with neuro-acanthocytosis may report inability to feed themselves because of dystonic tongue protrusion every time they wish to

Other features include cognitive and personality changes, dysphagia, dysarthria, amyotrophy, areflexia, evidence of axonal neuropathy with absent deep ankle tendon stretch reflexes, and elevated serum creatine kinase without evidence of myopathy.
Senile chorea:
This clinical entity is characterized by gradual onset of generalized and symmetric chorea with slow progression
and specifically excluding mental deterioration, emotional disturbances, or family history; therefore, neurogenetic
testing (CAG repeat) should be performed.
Sydenham chorea
Sydenham chorea is a major manifestation of acute rheumatic fever. With the 1992 modifications of the Jones criteria, it alone
is sufficient to enable the physician to make the diagnosis of the first attack of acute rheumatic fever. It is considered a
disease of childhood; however, it also may be seen in adults. Rheumatic chorea is characterized by muscle weakness and the
presence of chorea. The patients have the milkman grip sign, clumsy gait, and explosive bursts of dysarthric speech.

Psychological symptoms are equally prominent and typically precede the appearance of even the most subtle choreiform movements. Emotional lability is the most common symptom; decreased attention span, obsessive-compulsive symptoms, and separation anxiety disorder also are seen. Symptoms can lag behind the etiologic streptococcal infection by 1-6 months. In adults, generalized
poststreptococcal chorea may complicate birth control pills or pregnancy (chorea gravidarum).
Benign hereditary chorea
This is a rare autosomal dominant genetic disorder characterized by non-progressive choreiform movements appearing in childhood, without intellectual impairment. It is further distinguished clinically from juvenile HD by the absence of seizures, rigidity, or cerebellar features.
It does not shorten the life span of affected patients but severely affected patients can be severely disabled by the chorea.
Since HD is the most clearly defined choreatic disease, its physical findings
are described here.

Huntington disease
  • Chorea generally is initiated by flickers in the fingers and tic-ticlike grimaces of the face. With time, higher amplitude "dancelike movements disrupt voluntary actions of the extremities and interfere with gait. Speech becomes
  • Characteristically, the patient is hypotonic, though reflexes may be augmented and clonus may be noted.
  • Voluntary gaze is disturbed early. In particular, saccades may be irregular or of prolonged latency and may require an initial blink for their initiation.
  • Loss of optokinetic nystagmus is characteristic after a decade of progressive disease.
  • Cognitive changes are manifested early as loss of recent memory and impaired judgment. Apraxia is also present
  • Neurobehavioral changes typically consist of personality changes, apathy, social withdrawal, agitation, impulsiveness,
    depression, mania, paranoia, delusions, hostility, hallucinations,
    or psychosis.
  • The "Westphal variant" is dominated by rigidity,bradykinesia,
    and dystonic postures. Generalized seizures and myoclonus may be seen.
  • Ataxia and dementia are also present.
Idiopathic - Physiological chorea of infancy, buccal-oral-lingual dyskinesia,
senile chorea
HD, hereditary nonprogressive chorea (benign hereditary chorea), benign
recessively inherited choreo-athetosis of early onset, familial inverted chorea, neuroacanthocytosis, familial remitting chorea, nystagmus and cataracts, ataxia-telangiectasia, tuberous sclerosis, familial calcification of basal ganglia, Hallevorden-Spatz disease, Friedreich ataxia
Hereditary (metabolic)
Wilson disease, glutaric aciduria, Lesch-Nyhan disease, phenylketonuria, acute intermittent porphyria, propionic acidemia, abetalipoproteinemia, lipid storage diseases
Other metabolic and endocrine disorders
Kernicterus, hyperthyroidism hypo-parathyroidism, hypoglycemia, nonketotic
hyperglycemia, chorea gravidarum, hypo-magnesemia, chronic nonfamilial hepatic encephalopathy, anoxic encephalopathy (including postcardiac transplantation), post-portocaval anastomosis for portal hypertension
Paroxysmal kinesogenic choreoathetosis, paroxysmal dystonic choreoathetosis
Infectious - Sydenham chorea, encepha-litides, subacute sclerosing panencephalitis,
syphilis, enteric cytopathogenic human orphan (ECHO) virus, Lyme disease, HIV infection, cerebral toxoplasmosis, Creutzfeldt-Jakob disease, subacute bacterial endocarditis
Drug induced
Neuroleptics, levodopa, anticholinergics, oral contraceptives, antihistamines,
amphetamines, cocaine, phenytoin, tricyclics,
Alcohol intoxication and withdrawal, carbon monoxide, manganese, mercury
Cerebrovascular disease (ischemic or hemorrhagic), chronic subdural hematoma, Moyamoya disease, migraine/hemicrania choreatica, Churg-Strauss syndrome, polycythemia vera
Systemic lupus erythematosus, primary antiphospholipid antibody syndrome,
multiple sclerosis, postcardiac transplantation, postvaccination
Tumors - Primary, metastatic
Miscellaneous - Mitochondrial cytopathies, ventriculoperitoneal shunts
Chorea Gravidarum
Huntington Disease
Neuroacanthocytosis Syndromes
Wilson Disease

Lab Studies:

The diagnosis of the primary choreatic conditions is based on history and
clinical findings; however, several laboratory studies are useful, especially
in distinguishing the secondary forms of chorea from the primary forms. Some of them are mentioned here.

Huntington disease:
The only laboratory study presently available to confirm HD is genetic testing.
It identifies a gene abnormality in the short arm of chromosome 4, characterized by abnormal repetition of the trinucleotide CAG, the length of which determines the age of onset (anticipation).
Wilson disease:
A low serum ceruloplasmin level and serum copper with increased urinary copper excretion corroborate the diagnosis in most cases. Persistent aminoaciduria,
reflecting a renal tubular abnormality, is present in most but not all patients. Liver function test results are usually abnormal. Serum ammonia may be elevated. If diagnosis is still uncertain, liver biopsy will help confirm the diagnosis.
Sydenham chorea:
The chorea can lag behind the etiologic streptococcal infection by 1-6 months,
sometimes as long as 30 years; therefore, antistreptococcal antibody titers may
no longer be elevated at presentation. Without documentation of an antecedent
streptococcal infection, the diagnosis of Sydenham chorea must be made by
excluding other causes.
The diagnosis is confirmed by the presence of spiky erythrocytes (acanthocytes)
 in peripheral blood smears. The serum creatine kinase may be elevated.
Other laboratory studies
useful in the differential diagnosis of chorea include complement levels, antinuclear antibody (ANA) titers, antiphospholipid antibody titers, amino acids in serum and urine, enzymatic studies from skin fibroblasts, thyroid-stimulating hormone (TSH), thyroxine (T4), and parathormone (PTH).
Imaging Studies:
Patients with HD and choreo-acanthocytosis show decreased signal in the neostriatum, caudate, and putamen. No significant difference has been observed between these diseases. The decreased neostriatal signal corresponds to increased iron deposition.
Generalized atrophy, as well as focal atrophy of the neostriatum, predominantly of the caudate, with resulting enlargement of the frontal horns, follows the initial findings of decreased neostriatal signal.
Most cases of Sydenham chorea show no abnormalities. However, a study reported volumetric differences in the caudate, putamen, and globus pallidus; they were significantly larger in patients with
Sydenham chorea than in controls.
Patients with hemiballismus
demonstrate signal changes in the contralateral subthalamic nucleus or, less often, the striatum or thalamic nuclei.
MRI of the brain of patients with senile chorea shows a decrease in signal intensity throughout the striatum (suggesting iron deposition) and narrowing of the space separating the caudate head and putamen,
but no overt atrophy of these structures.
Positron emission tomography
Fluorodopa (F-dopa) uptake is normal or mildly reduced in patients with chorea. HD and choreo-acanthocytosis show bilateral hypometabolism in the caudate nucleus and putamen.
Patients with chorea and dementia show decreased glucose metabolism in the frontal, temporal, and parietal cortices.
Patients with benign hereditary chorea may or may not show decreased metabolism in the caudate.
The finding of normal cerebral glucose metabolism in the striatal region practically rules out HD, this being a useful
tool for differential diagnosis. The definite diagnosis of HD is made easily by neurogenetics.
Hypometabolism in the caudate nucleus and putamen on the contralateral side is seen in patients with hemichorea.
Medical Care:
  •  Only symptomatic treatment is available for patients with chorea.
    Chorea may be a disabling symptom, leading to bruises, fractures, and falls, and impairing the ability of patients to feed themselves. In addition, patients sometimes express a desire for antichorea treatment for cosmetic reasons.
  • The most widely used agents in treatment of chorea are the
    neuroleptics. The basis of their mechanism of action is thought to
    be related to blocking of dopamine receptors. Neuroleptics can be classified as typical and atypical.
  • Typical neuroleptics include
    haloperidol and fluphenazine. Atypical neuroleptics include risperidone, olanzapine, clozapine, and quetiapine. Dopamine-depleting agents, such as reserpine and tetrabenazine, represent another option in the treatment of chorea.
  • GABAergic drugs, such as clonazepam and gabapentin, can be used as adjunctive therapy.
  • Intravenous immunoglobulin and plasmapheresis may shorten the
    course of the illness and decrease symptom severity in cases of
    Sydenham chorea
  • Chorea following cardiac trans-plantation has been reported to be
    responsive to steroid treatment.
  • Reports of drug treatment in hemiballism must take into account the high spontaneous remission rate of the disorder. Anecdotal reports
    must be viewed with caution, unless they can demonstrate that the
    response is due to the agent (by recurrence of the movements with
    drug withdrawal). The rarity of this disorder and the severity of its
    manifestations have precluded placebo-controlled drug trials. 
    Pharmacologic treatment is the same as that prescribed for other
    choreatic disorder
The goals of pharmacotherapy are to reduce morbidity and prevent complications.
Drug Category: Antipsychotic agents 
These agents block dopamine receptors and appear to have antispasmodic effects.
Drug Name
Haloperidol (Haldol) -- Useful in treatment of irregular spasmodic movements of limbs or facial muscles.
Adult Dose Initial doses should be low: 0.5-1 mg/d PO; doses >10 mg/d have yielded little or no increased benefit over lower doses
Pediatric Dose Not established
Contraindications Documented hypersensitivity; narrow-angle glaucoma; bone marrow suppression; severe cardiac or liver disease; severe hypotension; subcortical brain damage
Interactions May increase serum concentrations of TCAs and hypotensive action of antihypertensive agents; phenobarbital or carbamazepine may decrease effects; anticholinergics may increase intraocular pressure; lithium may cause encephalopathy-like syndrome
Pregnancy C - Safety for use during pregnancy has not been established.
Precautions Patients may experience extrapyramidal symptoms, such as rigidity, akinesia, acute dystonic reactions, tardive dyskinesia, and neuroleptic malignant syndrome; less likely than other antipsychotic agents to cause sedation and hypotension
Drug Name
Fluphenazine (Prolixin) -- Blocks postsynaptic mesolimbic dopaminergic D1 and D2 receptors in brain. Exhibits strong alpha-adrenergic and anticholinergic effects. May depress reticular activating system.
Adult Dose 0.5-1 mg/d PO initially
Pediatric Dose Not established
Contraindications Documented hypersensitivity; narrow-angle glaucoma
Interactions May potentiate effects of narcotics, including respiratory depression; lithium increases CNS effects; barbiturates may decrease effects
Pregnancy C - Safety for use during pregnancy has not been established.
Precautions Besides extrapyramidal symptoms as described for haloperidol, mild leukocytosis, leukopenia, and eosinophilia occasionally occur; dermatological reactions are common; watch for urinary retention, blurred vision, dry mouth, and constipation as result of anticholinergic effects
Drug Name
Clozapine (Clozaril) -- New atypical neuroleptic medication available in 25 mg and 100 mg tablets. Blocks norepinephrine, serotonergic, cholinergic, histamine, and dopaminergic receptors. Mechanism of action still unclear. Affinity for mesolimbic D4 dopamine receptor ~~~~~~~~ for striking effects in control of behavioral and psychiatric symptoms with low incidence of extrapyramidal symptoms. Histamine receptor blockade ~~~~~~~~ for increased incidence of sleep disturbances.
Adult Dose Chorea: 12.5 mg PO qd; increase dose weekly to 50-75 mg PO qd
Dystonia: Doses of up to 700 mg/d may be needed
PD: 25-50 mg PO qd required to control hallucinations
Schizophrenia: Higher doses required
Pediatric Dose Not established
Contraindications Documented hypersensitivity; history of agranulocytosis; history of pulmonary embolism, diabetes mellitus, hepatitis, narrow-angle glaucoma, bladder retention, prostate enlargement
Interactions Epinephrine and phenytoin may decrease effects; other dopamine-depleting agents, TCAs, neuroleptics, CNS depressants, guanabenz, and anticholinergics may increase effects
Pregnancy C - Safety for use during pregnancy has not been established.
Precautions Monitor for agranulocytosis and orthostatic hypotension; caution in patients who take other drugs that can cause agranulocytosis, such as carbamazepine and ticlopidine; all patients should undergo weekly WBC counts with differential; if WBC falls below 3000/mm3 or if absolute neutrophil count falls below 1500/mm3, clozapine therapy should be interrupted or discontinued; anticholinergic reactions can be quite severe; may cause pulmonary embolism or hepatitis; may elevate LFTs
Drug Name
Olanzapine (Zyprexa) -- May inhibit serotonin, muscarinic, and dopamine effects.
Adult Dose 5-10 mg qd PO initially; increase to 10 mg PO qd within 5-7 d; not to exceed 20 mg/d
Pediatric Dose Not established
Contraindications Documented hypersensitivity
Interactions Fluvoxamine may increase effects; antihypertensives may increase risk of hypotension and orthostatic hypotension; levodopa, pergolide, bromocriptine, charcoal, carbamazepine, omeprazole, rifampin, and cigarette smoking may decrease effects
Pregnancy C - Safety for use during pregnancy has not been established.
Precautions Agranulocytosis has not been reported to date; watch for orthostatic hypotension and constipation; less risk of extrapyramidal effects than traditional neuroleptics; serum half-life increases by about 50% in patients older than 65 years and can be expected to increase in patients with liver dysfunction; both patient groups may require smaller than average dosages
Drug Name
Risperidone (Risperdal) -- Binds to dopamine D2-receptor with 20 times lower affinity than for 5-HT2 receptor. Improves negative symptoms of psychoses and reduces incidence of extrapyramidal adverse effects.
Adult Dose 1 mg PO bid initially; increase slowly to 4-6 mg/d
Pediatric Dose Not established
Contraindications Documented hypersensitivity
Interactions Carbamazepine may decrease effects; may inhibit effects of levodopa; clozapine may increase levels
Pregnancy C - Safety for use during pregnancy has not been established.
Precautions Low risk of extrapyramidal adverse effects; may cause extrapyramidal reactions, hypotension, tachycardia, and arrhythmias
Drug Name
Quetiapine (Seroquel) -- May act by antagonizing dopamine and serotonin effects.
Adult Dose 25 mg PO bid initially; titrate slowly to effect in 2-3 divided doses; not to exceed 800 mg/d
Pediatric Dose Not established
Contraindications Documented hypersensitivity
Interactions May antagonize levodopa and dopamine agonists; phenytoin, thioridazine, and other liver enzyme inducers may reduce levels
Pregnancy C - Safety for use during pregnancy has not been established.
Precautions May induce orthostatic hypotension associated with dizziness, tachycardia, and syncope; neuroleptic malignant syndrome has been associated with this treatment
Drug Category: Dopamine depleting agents
These agents deplete the central nervous system of dopamine,
thereby reducing chorea.
Drug Name
Reserpine (Serpasil) -- Depletes norepinephrine and epinephrine, which in turn depress sympathetic nerve functions.
Adult Dose 0.5 mg PO qd; titrate to 1.0 mg PO qd
Pediatric Dose Not recommended
Contraindications Documented hypersensitivity; diagnosed mental depression
Interactions Tricyclic antidepressants may decrease antihypertensive effects; either digitalis or quinidine may increase risk of cardiac arrhythmia
Pregnancy C - Safety for use during pregnancy has not been established.
Precautions Sedation and inability to concentrate or perform complex tasks are most common adverse effects; occasional psychotic depression may occur that can lead to suicide (usually appears insidiously over many weeks or months and may not be attributed to drug because of delayed and gradual onset of symptoms); must be discontinued at first sign of depression; do not give to patients with history of depression; other adverse effects include nasal stuffiness and exacerbation of peptic ulcer disease; orthostatic hypotension may occur but does not usually cause symptoms; parkinsonism may present as adverse effect
Drug Name
Tetrabenazine (Nitoman) -- Dopamine-depleting agent available worldwide except in United States. Works by depleting dopamine in presynaptic neuron and by blocking postsynaptic dopamine receptor.
Adult Dose 25 mg PO qd initially; increase dose according to clinical response and adverse effects
Pediatric Dose Not established
Contraindications Documented hypersensitivity; depression
Interactions Potentiates effects of other dopamine-depleting agents (ie, reserpine) and of dopamine-blocking agents such as neuroleptics
Pregnancy X - Contraindicated in pregnancy
Precautions See contraindications; patients may develop sedation, anxiety, akathisia, confusion, tremor, and dizziness; should use caution in orthostatic and drug-induced hypotension; because tetrabenazine depletes dopamine, tends to worsen symptoms of parkinsonism/Parkinson disease or drug-induced parkinsonism
Drug Category: Benzodiazepines
That these agents reduce GABA concentrations in the caudate,
putamen, substantia nigra, and globus pallidus has been
demonstrated. By analogy, increased GABA activity might ameliorate
Drug Name
Clonazepam (Klonopin, Rivotril) -- Developed as antiepileptic, hypnotic, and anxiolytic used as adjunct for treatment of chorea. Belongs to benzodiazepine group, increasing GABAergic transmission in CNS. Reaches peak plasma concentration at 2-4 h after oral or rectal administration.
Adult Dose 0.5 mg PO qd; increase dose weekly according to need and response
Pediatric Dose Not established
Contraindications Documented hypersensitivity; severe liver disease; acute narrow-angle glaucoma
Interactions Phenytoin and barbiturates may reduce effects; CNS depressants increase toxicity
Pregnancy C - Safety for use during pregnancy has not been established.
Precautions Caution in chronic respiratory disease or impaired renal function; withdrawal symptoms can result from abrupt discontinuation of medication; main adverse effects include sedation, tolerance, ataxia, depression, and confusion


Some patients may develop rhabdomyolysis or local trauma due to the severity of the abnormal involuntary movements.
Aspiration pneumonia may result in early death in some patients with neuro-acanthocytosis owing to the swallowing difficulties and tongue dystonia usually present in these patients.
Prognosis depends on the cause of the chorea. HD has a poor prognosis, as all patients will die of complications of the disease.
Similarly, patients with neuro-acanthocytosis may develop aspiration pneumonia resulting in early death.
eMedicine Journal, July 12 2001, Volume 2, Number 7 See BIBLIOGRAPHY
Authored by Maria Alejandra Herrera, MD, Fellow, Department of Neurology,
The Cleveland Clinic Florida Coauthored by Nestor Galvez-Jimenez, MD,
Program Director, Associate Professor, Department of Neurology, Division of
Medicine, Cleveland Clinic Florida

eMedicine Journal, July 12 2001, Volume 2, Number 7
See URL for