Our job can be deeply satisfying. When you are able to relieve a patient’s pain or able to help detect impending disaster and avoid it, you feel like a superhero. Sometimes something as simple a fixing a Nursemaid’s Elbow will make your day! On the other hand, however, if you give a patient a medicine and the condition worsens you can feel like a fraud. Unfortunately, medication-induced dystonic reactions do occur even when you are striving to “first do no harm.”

Extrapyramidal Syndromes

• Parkinsonism
  • Tremor, rigidity, mask-like facial expression, and/or bradykinesia
• Akathisia
  • Restlessness and an internal feeling of unease
• Dystonia
  • Abnormal tonic muscle contractions
  • Can include dyskinesias = clonic muscular contractions

Dystonic Reactions

• Dystonia = movement disorder of sustained involuntary muscle contractions.
  • May present as twisting, abnormal postures or the neck, jaw, tongue or torso.
  • May also lead to eye deviation, dysphagia, dysarthria, or even dyspnea.
  • Buccolingual dystonia is the most common form. [Hooker, 1988]
    • Consists of dysarthria, mutism, trismus, tongue protruding or retracting, facial grimacing / distortions.
  • Torticollic dystonia is the 2^nd most common form.

• Mechanism is unclear, although thought to be due to an imbalance between cholinergic and dopaminergic stimulation.
  • Dopamine antagonists (ex, antipsychotics, antiemetics, and GI motility agents) often associated with dystonic reactions. [Derinoz, 2013]
  • Anticholinergic agents (ex, diphenhydramine) often used to treat it.
• Does not indicate an overdose.
  • One study found 70% of dystonic reactions occurred within therapeutic doses. [Derinoz, 2013]
• Consider over-the-counter medications (~18% in Derinoz’s study were due to OTC meds).

Common Offending Agents in the Ped ED

• Antiemetics (ex, metoclopramide, promethazine)
  • Ondansetron has practically revolutionized management in the Peds ED of vomiting, because it is less likely to cause dystonic reactions.
  • While there is less risk of dysonia with ondansetron, it still can occur. [Sprung, 2003]
• Antipsychotics (ex, Haloperidol, Risperidone, Chlorpromazine)
• Antiepileptics (ex, Pheytoin, Carbamazepine)
• Sedatives (ex, Benzodiazepines) [Hooker, 1988]
  • Paradoxical Reactions can also be seen with Benzodiazepines.
  • The patient becomes agitated and delirious.
  • Flumazenil administration has been reported to be helpful to alleviate these symptoms. [Jackson, 2015]

Diphenhydramine to the Rescue

• H1-antagonism is effective in relief of dystonic symptoms.
• Can be given orally, intravenously, or intramuscularly.
• Interestingly… diphenhydramine can also CAUSE dystonic reactions.

Other Entities to Consider

• Deep space neck abscess (Retropharyngeal abscess)
• Tetanus
• Seizure
• Calcium deficiency
• Drug intoxication
• Meningitis / Encephalitis
• Stroke
• Conversion disorder

References