PEMPix is the American Academy of Pediatrics Section on Emergency Medicine’s visual diagnosis competition. It is held annually at the National Conference and Exhibition. This year, all ten finalists will be posted online on and at, one a day with voting opening to AAP Section on Emergency Medicine members thereafter. I hope you enjoy this online-only format, and hope that it will serve to highlight some of the fantastic learning cases that our colleagues submitted this year. It was again very difficult for the panel of judges to select the finalists and I could not have done it without their assistance. As a special treat I’ve included a musical selection form the 1980s as an optional “hint,” and to serve as a soundtrack for your learning.

This PEMPix case was submitted by:

Gretchen Fuller, MD, Pediatric Emergency Medicine Fellow and Andrew Kienstra, MD,  from the University of Texas at Austin Dell Children’s Medical Center


Weekly weakness

An 11 year-old boy presents with a two day history of right arm and leg weakness with right facial droop. It is difficult for him to walk or dress himself. Parents report weekly episodes of similar transient weakness without an obvious trigger. He was evaluated by neurology two years prior and had a normal video EEG during a captured episode. He takes no medications and has no known drug allergies. Review of systems is notable for frequent headaches. There are no other symptoms. Family history includes his mother’s migraines and a paternal uncle with seizures. His vital signs are normal. Notable exam findings include

  • Alert and oriented
  • Pupils equal round and reactive to light
  • Extraocular movements intact
  • No papilledema
  • Normal speech
  • The right nasolabial fold is flattened
  • 4/5 strength right upper extremity and right lower extremity, 5/5 strength in the left upper extremity and left lower extremity
  • Normal sensation
  • Reflexes 2+ in bilateral upper extremities and 1+ in bilateral lower extremities
  • No tremor
  • Stiffness/slightly increased tone of right upper and lower extremity
  • The remainder of the exam is unremarkable

His workup included a normal CBC and complete metabolic panel. A brain MRI was also obtained and was normal.

What is the diagnosis?

A. Conversion disorder

B. Paroxysmal dyskinesia

C.Transient ischemic attacks

D. Seizures with Todd’s paralysis

E. Heavy metal poisoning

B. Paroxysmal dyskinesia

Paroxysmal dyskinesia is a genetically and clinically heterogeneous group of syndromes characterized by recurrent attacks of abnormal, hyperkinetic movements in which consciousness is usually maintained. It is classified according to its precipitating factors:

  • Paroxysmal kinesigenic dyskinesia (PKD)
  • Paroxysmal non-kinesigenic dyskinesia (PNKD)
  • Paroxysmal exercise-induced dystonia (PED)
The age of onset varies; typically between 4-15 years and commonly involves PRRT2, SLC2A1, or MR-1 mutations. It is often autosomal dominant, but can be due to a de novo mutation as well.

Pharmacologic and nonpharmacologic treatments include:

  • Benzodiazepines
  • Sodium channel blockers
  • Ketogenic diet

Paroxysmal dyskinesia is often associated with infantile seizures, epilepsy, migraines, ataxia, tremors.

Why were the other choices incorrect?

  • Conversion disorder is often linked to an acute stressor. This patient’s exam would be difficult to feign.
  • Transient ischemic attacks would be brief. This patient had two days of persistent symptoms.
  • Seizure activity would have been evident on video EEG during a captured episode.
  • Heavy metal poisoning involves persistent symptoms, often including nausea, vomiting, diarrhea, and abdominal pain.

This young man’s symptoms improved markedly improved with lorazepam. Neurology eventually diagnosed him with paroxysmal non-kinesigenicdyskinesia (PNKD) and recommended outpatient genetic testing and clonazepam as needed. In the future they may consider adding daily carbamazepine.


Kim S, Lee J, Kim W, Kim H, Choi S, Lim B, Kim K, Chae J. Paroxysmal Dyskinesia in Children: from Genes to the Clinic. J Clin Neurol. 2018 Oct;14(4):492-497.

Latorre A and Bhatia K. Treatment of Paroxysmal Dyskinesia. Neurol Clin. 2020 May;38(2):433-447.

McGuire S, Chanchani S, Khurana D. Paroxysmal Dyskinesias. Semin Pediatr Neurol. 2018 Apr;25:75-81.