Tic disorders: Opt for dopamine receptor blockers
Tics are involuntary or semivoluntary movements or sounds that are sudden, brief, intermittent, repetitive, nonrhythmic, unpredictable, and purposeless. Tics can occur in any part of the body.20
The most common tic disorder is Tourette syndrome—a combination of motor and phonic tics with onset before age 21. It affects approximately 5 to 10 children out of 10,000. Boys are more commonly affected than girls. Attention deficit hyperactivity disorder frequently accompanies this syndrome.2
The goal of treatment with any tic disorder is to improve social functioning, self-esteem, and quality of life. Education and support of patients is important. Tic disorders, including Tourette, rarely require drugs. But if tics become too distressing, first-line treatment would be a dopamine modulator, tetrabenazine, or clonidine. Randomized controlled trials with various neuroleptics have revealed dramatic reductions in tic severity. However, many patients do not tolerate the acute adverse effects (most commonly sedation, weight gain, depression, lethargy, and akathisia), and prolonged treatment confers a small risk of tardive dyskinesia. Behavioral therapy is an important part of management.20
Dopamine-receptor blocking drugs such as haloperidol, pimozide, and fluphenazine are the most effective treatment for tics20 (SOR: B). Tetrabenazine is a promising new dopamine-depleting drug; controlled trials are ongoing2,20 (SOR: B). Clonidine, an alpha 2-adrenergic agonist, is useful in treating patients with Tourette syndrome, helping to improve sleep and attention2,21 (SOR: C). Medically refractory motor and disabling phonic tics such as coprolalia can be ameliorated by botulinum toxin injections21 (SOR: B). Deep brain stimulation is being used at an increasing rate for medically refractory tics in Tourette syndrome21 (SOR: B).
Restless legs syndrome: Dopamine agonists are preferred
Restless legs syndrome (RLS) is a disorder characterized by sensory symptoms and motor disturbances of the legs, mainly during rest. Treatment may not be necessary for patients with mild or sporadic symptoms. For moderate to severe RLS with significant impairment, dopamine agonists are the preferred agents22 (SOR: A). RLS can also occur secondary to such conditions as iron deficiency and uremia, and correction of the underlying disorder is the goal. Prescribe iron replacement for patients with a ferritin level <50 ng/mL22 (SOR: C). Medications known to cause or exacerbate the symptoms of RLS are anti-dopaminergic agents (such as neuroleptics), diphenhydramine, tricyclic antidepressants, alcohol, caffeine, lithium, and beta-blockers. If a patient is taking medications that exacerbate symptoms of RLS, discontinue them and use appropriate substitutes22 (SOR: C).
Myoclonus: Clonazepam for essential disorder
Myoclonus is a brief, sudden, shock-like movement caused by involuntary muscle contractions or lapse of muscle contraction (asterixis). Given the complex origins of myoclonus, multiple drugs may be needed. Essential myoclonus is disabling and can be treated with clonazepam. Start with 0.25 mg orally twice daily, and increase the dosage over 3 days to 1 mg/d23 (SOR: C). Most cases of myoclonus are secondary due to drugs such as lithium, toxins, advanced liver disease, infections including human immunodeficiency virus, dementia, and brain lesions. Treatment should also address the underlying disorder.2,23
Chorea
Chorea is an abnormal involuntary movement disorder described as “a state of excessive, spontaneous movements, irregularly timed, nonrepetitive, randomly distributed, and abrupt in character.”24
Treatment of chorea is symptomatic, aiming to reduce morbidity and prevent complications. Haloperidol and fluphenazine are effective but can impair voluntary movements2,10,25 (SOR: C). The dopamine-depleting drugs reserpine and tetrabenazine are also effective2,10,25 (SOR: C). GABAergic drugs, such as clonazepam, gabapentin, and valproate, can be used adjunctively.10,25
Dystonia
Dystonia is a syndrome involving sustained contractions of opposing muscles that cause twisting, repetitive movements and abnormal postures. Primary dystonia can be treated successfully with high doses of trihexyphenidyl alone, starting with 1 mg orally per day and increasing gradually to 6 to 80 mg/d until symptoms are controlled; or in combination with baclofen, starting with 10 mg orally once daily and increasing to a maximum dose of 30 to 120 mg/d1,2 (SOR: C).
Consider botulinum neurotoxin injection for focal upper extremity dystonia and adductor spasmodic dysphonia16 (SOR: B).
Ataxia
Ataxia is an unsteady gait associated with cerebellar dysfunction, proprioceptive defects, or both. Ataxia may be primary (Friedreich ataxia and spinocerebellar ataxia) or secondary to stroke, trauma, alcoholic degeneration, multiple sclerosis, vitamin B12 deficiency, and hydrocephalus. Treatment, when possible, should target the underlying cause.1,2
CORRESPONDENCE Hakan Yaman, MD, Akdeniz University, Department of Family Medicine, Antalya, Turkey 07058; hakanyaman@akdeniz.edu.tr