Rosen & Barkin's 5-Minute Emergency Medicine Consult (230 page)

• Normal pattern of CNS neurotransmission maintained by balance between dopaminergic and cholinergic receptors:
  
  • Certain drugs antagonize dopamine receptors in the basal ganglia resulting in an imbalance of dopaminergic and cholinergic stimulation
    
  • This imbalance leads to acute involuntary muscle spasms of the face or neck (the trunk, pelvis, or extremities can also be affected)
    
• Although the spasms are uncomfortable and frightening, they are not life threatening except in very rare cases when laryngeal muscles are involved
  
• Usually occurs within hours of ingestion:
  
  • Almost always within 1st wk after exposure to offending drug
    
• Risk factors:
  
  • Children and young adults are at higher risk
    
  • Rarely occurs in patients over 45 yr of age
    
  • Males more often affected
    
  • Prior episodes of dystonia significantly increase risk
    
  • Recent cocaine use increases risk
    

• Usually occurs after patient has taken antipsychotic, antiemetic, or antidepressant drug
  
• Incidence of dystonic reactions varies widely (2–25%) depending on the potency of the agent
  
• Higher with more potent drugs (haloperidol, fluphenazine)
  
• Lower with less potent drugs (chlorpromazine, thioridazine)
  
• Lowest with atypical antipsychotics (quetiapine, olanzapine, risperidone)
  
• Antiemetic agents:
  
  • Metoclopramide (Reglan)
    
  • Prochlorperazine (Compazine)
    
  • Promethazine (Phenergan)
    
  • Droperidol (Inapsine)
    
• Other agents:
  
  • Cyclic antidepressants
    
  • H
    ₂
    blockers
    
  • Some antimalarial agents
    
  • Antihistamines
    
  • Some anticonvulsants
    
  • Doxepin
    
  • Lithium
    
  • Phencyclidine
    

Children are particularly vulnerable to dystonic reactions when dehydrated or febrile

DIAGNOSIS

• Ingestion of neuroleptic, antiemetic, or other drug within week of symptom onset
  
  • May occur in patients on neuroleptic agents who increase their dose of neuroleptics or reduce medications (anticholinergic agents) used to treat extrapyramidal symptoms
    
• Difficulty with vocalization
  
• Completely alert and able to answer questions, although facial muscle involvement may make speech difficult.
  
• Involuntary muscle contractions or spasms usually involving the face or neck (see “Physical Exam”):
  
  • Muscles of the trunk, pelvis, or extremities can also be involved
    

• Characteristic involuntary muscle spasms occur
  
• Oculogyric crisis
  
  • Involves eye and periorbital muscles
    
  • Evolves into painful upward or lateral deviation of the eyes
    
• Blepharospasm
  
  • Involuntary eyelid closure
    
• Buccolingual crisis
  
  • Involves facial muscles and the tongue
    
  • May have difficulty speaking
    
  • Facial grimacing
    
  • Trismus
    
  • Tongue protrusion
    
  • Dysphagia
    
• Spasmodic torticollis
  
  • Twisting of the neck
    
• Torticopelvic crisis
  
  • Abdominal wall muscle spasm
    
• Opisthotonos
  
  • Involves muscles of trunk and back
    
  • Twisting and arching of spine
    
• Laryngeal dystonia
  
  • Very rare but potentially life threatening
    
  • May develop airway obstruction due to laryngospasm
    
  • Presents as dysphonia or stridor
    

• Clinical diagnosis is based on characteristic signs and symptoms with history of possible drug exposure
  
• Diagnosis is confirmed by response to treatment
  
  • Lack of response to treatment should lead one to consider alternative diagnosis
    

• Lab testing not routinely indicated
  
• If no response to treatment, hypocalcemia should be considered and calcium level obtained
  

No imaging studies needed

• Tardive dyskinesia:
  
  • Complication of chronic antipsychotic therapy
    
  • Usually choreiform movements
    
  • Does not rapidly improve with administration of anticholinergic drug
    
• Akathisia:
  
  • Involuntary motor restlessness
    
  • May appear agitated
    
• Seizure:
  
  • History of prior seizures
    
  • Not responsive to verbal stimuli
    
  • Tonic–clonic-type motor movements rather than spasm
    
• Hysteria or pseudoseizure:
  
  • History of precipitating emotional event
    
  • Tonic–clonic motor activity rather than sustained spasm
    
• Tetanus
  
• Strychnine poisoning
  
• Chronic dystonias:
  
  • Cerebral palsy, familial choreas
    
  • Usually history of dystonia is associated with chronic neurologic process
    
• Scorpion envenomation:
  
  • Oculogyric crisis and opisthotonos are common manifestations of scorpion envenomation
    
  • Patient lacks history of drug exposure.
    
• Meningitis and encephalitis may present with atypical seizures that mimic dystonic reaction
  
• Mandible dislocation
  
• Hypocalcemia
  

TREATMENT

• Rarely life threatening
  
• Direct attention toward spasm of larynx and tongue to be sure dystonic reaction is not causing respiratory compromise
  
• Ask family and friends about ingestions of antipsychotic medications, antiemetics, and recreational drugs
  
• Transport pill bottles
  

Stabilize airway to prevent spasm of larynx or tongue from causing respiratory compromise.

• Administer diphenhydramine (Benadryl) or benztropine mesylate (Cogentin):
  
  • Rapid resolution of muscular spasm by restoring cholinergic–dopaminergic balance in CNS
    
  • IV administration is preferred route of treatment
    
  • Onset of relief in 2–5 min
    
  • Complete resolution of symptoms in 30 min
    
  • IM administration is alternate route of treatment
    
  • Begins to work in 15–30 min
    
  • Continue oral administration for 3 days to prevent redevelopment of symptoms
    
• Diazepam (Valium):
  
  • Administer in cases of dystonia unresponsive to adequate doses of anticholinergic medications
    
  • Failure to respond to standard treatment should lead physician to consider other diagnoses
    

• Benztropine mesylate (Cogentin): 1–2 mg either IV (over 2 min) or IM followed by 1–2 mg PO BID for 3 days:
  
  • Not to be used in children <3 yr old
    
  • For children >3 yr old: 0.02 mg/kg IV (over 2 min) or IM followed by 0.02 mg/kg PO BID for 3 days
    
• Diphenhydramine (Benadryl): 1–2 mg/kg up to 100 mg either IV (over 2 min) or IM followed by 25–50 mg (peds: 1–2 mg/kg) PO q6–8h for 3 days,
  or
  
• Diazepam: 5–10 mg IV followed by 5 mg PO q4–6h as necessary for 3 days
  

Diphenhydramine (Benadryl)

Benztropine mesylate (Cogentin):

• Not to be used in children <3 yr old
  
• Diazepam
  

FOLLOW-UP

• Patients are not admitted unless symptoms do not resolve with treatment, there are concerns about maintaining the airway, or the diagnosis is not certain
  
• If the dystonic reaction causes laryngospasm patient should be observed for 12–24 hr after symptoms resolve
  

• Discharge after resolution of symptoms
  
• The offending agent should be discontinued
  
• Patient should not drive or perform tasks that require full alertness while taking sedating medications
  

Patients should follow-up with the prescribing physician of the causative agent

• The diagnosis of acute dystonia is made based on the history of ingestion coupled with complete resolution of the symptoms after appropriate treatment
  
• 1st line of therapy is diphenhydramine
  
• Failure to respond should lead you to consider other diagnoses
  

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  Emerg Med J.
  2013;30:130–133.
  
• Goldfrank LR, Lewin NA, Howland MA, et al. Pathophysiology and clinical manifestations. In: Nelson LS, Lewin NA, Howland MA, et al., eds.
  Goldfrank’s Toxicologic Emergencies
  . 9th ed. New York, NY: McGraw Hill; 2011;9:1007–1010.
  
• Sachdev PS. Neuroleptic-induced movement disorders: An overview.
  Psychiatr Clin North Am
  . 2005;28:255–274.
  
• Vena J, Dufel S, Paige T. Acute olanzapine-induced akathisia and dystonia in a patient discontinued from fluoxetine.
  J Emerg Med
  . 2006;30:311–317.
  
• Wolfson AB, Hendey GW, Ling LJ, et al., eds.
  Harwood Nuss’ Clinical Practice of Emergency Medicine
  . 5th ed. Philadelphia, PA: Lippincott; 2010.
  

CODES