AUTHOR AND EDITOR INFORMATION

Section 1 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

INTRODUCTION

Section 2 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Background

Dystonic reactions are adverse extrapyramidal effects that often occur shortly after the initiation of neuroleptic drug therapy. These reactions may occur with a wide variety of medications. Dystonic reactions (ie, dyskinesias) are characterized by intermittent spasmodic or sustained involuntary contractions of muscles in the face, neck, trunk, pelvis, and extremities. Dystonic reactions are rarely life threatening, yet are very uncomfortable and often produce significant anxiety and distress for patients. Fortunately, treatment is extremely effective, and motor disturbances resolve within minutes.

Pathophysiology

Although dystonic reactions are occasionally dose related, these reactions are more often idiosyncratic and not predictable. They appear to result from drug-induced alteration of dopaminergic-cholinergic balance in the nigrostriatum (ie, basal ganglia). Most drugs produce dystonic reactions by nigrostriatal dopamine D2 receptor blockade, which leads to an excess of striatal cholinergic output. High-potency D2 receptor antagonists are most likely to produce an acute dystonic reaction. Agents that balance dopamine blockade with muscarinic M1 receptor blockade are less likely to produce a dystonic reaction. Paradoxically, an alternative cause of dystonic reactions may be increased nigrostriatal dopaminergic activity that occurs as a compensatory response to dopamine receptor blockade.

Frequency

United States

Incidence of acute dystonic reactions varies according to individual susceptibility, drug identity, dose, and duration of therapy. For patients on neuroleptics, the overall incidence of dystonic reactions is approximately 2%.

Mortality/Morbidity

• In rare instances, airway management may be needed.
• Dystonic reactions typically are not life threatening and result in no long-term effects.

Sex

Incidence of dystonic reactions is greater in males than in females.

Age

• These reactions are most common in children, teens, and young adults (ie, 5-45 years).
• The risk of reaction decreases as age increases.

CLINICAL

Section 3 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

History

Dystonic reactions most often occur shortly after initiation of drug treatment; 50% occur within 48 hours and 90% occur within 5 days of initiation of treatment. Risk factors include family history of dystonia, recent history of cocaine or alcohol use, or treatment with a potent dopamine D2 receptor antagonist (eg, fluphenazine, haloperidol).

• Onset of symptoms is sudden, usually within minutes to days of initiating or increasing dose of causative agent.
• Obtain history from others if patient is not able to speak.
• Obtain medication history, including new medications and/or dosage increase.

Physical

• Physical examination findings may include any of the following:
• • Oculogyric crisis, deviation of eyes in all directions
  • Buccolingual crisis
  • Protrusion of tongue
  • Trismus
  • Forced jaw opening
  • Difficulty in speaking
  • Facial grimacing
  • Torticollis, usually associated with oculogyric and buccolingual crisis
  • Opisthotonic crisis
  • Lordosis or scoliosis
  • Tortipelvic crisis - Typically involves hip, pelvis, and abdominal wall muscles, causes difficulty with ambulation
• Mental status is unaffected.
• Vital signs are usually normal.
• Remaining physical examination findings are normal.

Causes

• Drug-related adverse effects
• • Neuroleptics (antipsychotics), antiemetics, and antidepressants are the most common causes of drug-induced dystonic reactions.
  • Acute dystonic reactions have been described with every antipsychotic.
  • Alcohol and cocaine use increase risk.
• Predisposing factors
• • Family history of dystonia
  • Viral infections

DIFFERENTIALS

Section 4 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Other Problems to be Considered

Metabolic or respiratory alkalosis
Toxicity, strychnine
Oropharyngeal infections

TREATMENT

Section 5 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Emergency Department Care

• Emergency interventions other than pharmacologic treatment rarely are required.
• Securing the airway is necessary only rarely, when laryngeal and pharyngeal dystonic reactions place the patient at risk of imminent respiratory arrest.
• Pharmacologic treatment resolves the reaction.

MEDICATION

Section 6 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

The goals of pharmacotherapy are to reduce morbidity and prevent complications.

Drug Category: Anticholinergic agents

Intravenous anticholinergic agents are the treatment of choice. IV is the route of choice, with signs and symptoms often resolving within 10 minutes. The medication can be delivered IM if an IV line cannot be established, but medications will take 30 min to be absorbed. More than 1 dose may be necessary for complete resolution of dystonia.

Drug Category: Benzodiazepines

Normal balance between dopamine and acetylcholine in the basal ganglia involves modulation from GABA-containing striatonigral neurons. GABA-ergic neurons are inhibitory and antagonize excitatory dopaminergic neurons. GABA agonists (eg, benzodiazepines) may be helpful for acute dystonic reactions.

FOLLOW-UP

Section 7 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

In/Out Patient Meds

• Continue medication for 48-72 hours to prevent relapse.
• • Benztropine 1-2 mg PO bid
  • Diphenhydramine 25-50 mg PO qid
  • Trihexyphenidyl 2 mg PO bid

MISCELLANEOUS

Section 8 of 9  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical/Legal Pitfalls

• Failure to consider other diagnoses if symptoms have not abated after 2 IV doses of appropriate medication
• Failure to continue treatment for 48-72 hours to prevent relapse

Special Concerns

• Arrange psychiatric follow-up care if patient has a dystonic reaction while taking neuroleptic medication. When continued neuroleptic therapy is necessary, maintain patient on an anticholinergic agent or switch to a neuroleptic less likely to produce an acute dystonic reaction.

REFERENCES

Section 9 of 9

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

• Barach E, Dubin LM, Tomlanovich MC, Kottamasu S. Dystonia presenting as upper airway obstruction. J Emerg Med. May-Jun 1989;7(3):237-40. [Medline].
• Demetropoulos S, Schauben JL. Acute dystonic reactions from "street Valium". J Emerg Med. Jul-Aug 1987;5(4):293-7. [Medline].
• Elliott ES, Marken PA, Ruehter VL. Clozapine-associated extrapyramidal reaction. Ann Pharmacother. May 2000;34(5):615-8. [Medline].
• Fahn S. The varied clinical expressions of dystonia. Neurol Clin. Aug 1984;2(3):541-54. [Medline].
• Fines RE, Brady WJ, DeBehnke DJ. Cocaine-associated dystonic reaction. Am J Emerg Med. Sep 1997;15(5):513-5. [Medline].
• Herrstedt J. Risk-benefit of antiemetics in prevention and treatment of chemotherapy-induced nausea and vomiting. Expert Opin Drug Saf. May 2004;3(3):231-48. [Medline].
• Jhee SS, Zarotsky V, Mohaupt SM, et al. Delayed onset of oculogyric crisis and torticollis with intramuscular haloperidol. Ann Pharmacother. Oct 2003;37(10):1434-7. [Medline].
• Kumor K. Cocaine withdrawal dystonia. Neurology. May 1990;40(5):863-4. [Medline].
• Marsden CD, Jenner P. The pathophysiology of extrapyramidal side-effects of neuroleptic drugs. Psychol Med. Feb 1980;10(1):55-72. [Medline].
• McCormick MA, Manoguerra AS. Dystonic reaction. In: Harwood-Nuss A, et al, eds. Clinical Practice of Emergency Medicine. Lippincott Williams & Wilkins; 1991:510-511.
• Piecuch S, Thomas U, Shah BR. Acute dystonic reactions that fail to respond to diphenhydramine: think of PCP. J Emerg Med. May-Jun 1999;17(3):527. [Medline].
• Roberge RJ. Antiemetic-related dystonic reaction unmasked by removal of a scopolamine transdermal patch. J Emerg Med. Apr 2006;30(3):299-302. [Medline].
• Schumock GT, Martinez E. Acute oculogyric crisis after administration of prochlorperazine. South Med J. Mar 1991;84(3):407-8. [Medline].

Article Last Updated: Sep 30, 2008