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 PEMBlog.com and at PEMPix.com, 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:

Jason Miller, MD, Pediatric Emergency Medicine Fellow along with Amy Cortis, MD and Roopa Kannikeswaran, MD from the Children’s Hospital of Michigan

She’s wobbly and confused

A 17 year old female with a history of diabetes mellitus presented to the Emergency Department with wobbly gait and confusion that began seven days ago and has gotten progressively worse. She denies polyuria, polydipsia, abdominal pain. Review of symptoms is also negative for fever, headache, facial asymmetry, speech changes, weakness, sensory change, weight loss, trauma, and ingestion. Her most recent Hgb A1c was 15%, but she has not had significant hyperglycemia over the past week. She is managed by a basal-bolus insulin regimen.
 
 
On examination she is afebrile with mild tachycardia (heart rate 104 beats/min). her respiratory rate is 20 breaths/min (like everyone else’s), and her blood pressure is 133/96 mmHg. She appears tired, but alert, and looks well hydrated. Her pupils are normal, and the rest of the neurological exam reveals
delayed verbal responses but with appropriate response to commands. She is alert and oriented to person, place, and time. Cranial nerves II-XII are grossly intact. She has 5/5 strength all four extremities.  She demonstrates an ataxic, wide-based gait. She also has dysmetria with bilateral finger-to-nose. The reminder of the exam was normal.
 
Lab workup revealed that she was not in DKA, pregnancy was negative, and result of urine drug screen and ethanol levels negative as well.
 
Amazingly the team was able to obtain a STAT MRI fo the brain.
 
 

What is the diagnosis?

A. Posterior fossa cerebrovascular accident

B. Cerebral edema

C. Acute disseminated encephalomyelitis

D. Osmotic demyelination syndrome

E. Pontine glioma

D. Osmotic demyelination syndrome

This patient’s MRI demonstrated T2 hyperintensity of the pons and the surrounding basal ganglia diagnostic for osmotic demyelination syndrome (ODS). ODS is a rare neurologic sequela of osmotic stress, and in this case is associated with poorly controlled diabetes. Only 106 pediatric cases have been reported between 1960-2018. Classically, symptoms are delayed 2-6 days after a rapid correction of chronic hyponatremia. Other associations include:

  • Chronic alcoholism
  • Liver transplant
  • Poorly controlled diabetes mellitus
  • Diabetes insipidus
  • Renal failure
  • Refeeding syndrome
  • Burns

ODS clinical manifestations are varied and include dysarthria, dysphagia, quadriparesis/paraparesis, behavioral disturbances, movement disorders, seizures, and/ altered mental status. Osmotic myelinolysis is usually seen in areas of the brain containing both gray and white matter, such as the pons and basal ganglia. MRI is the diagnostic test of choice. In 46% of patients there are pontine findings (ie. central pontine myelinolysis). 28% of patients have extrapontine findings, and 26% of patients have pontine and extrapontine findings. Treatment is supportive with a possible role for IVIG and steroids in pediatric patients. Complete neurologic recovery occurs in 60% of pediatric patients.

A brainstem cerebrovascular accident would involve a specific watershed area with associated ipsilateral cranial nerve palsies and contralateral hemiparesis. Acute disseminated encephalomyelitis would involve multiple, asymmetric, and typically bilateral signal abnormalities throughout the brain and is classically associated with fever and meningeal signs. Cerebral edema is associated with acute diabetic ketoacidosis or hyperosmolar hyperglycemic state. And finally a pontine glioma would demonstrate infiltration or a mass effect.
 
To date the patient continues to have a wide-based gait and dysmetria two months after the initial presentation. She is able to ambulate short distances with support, otherwise she uses a wheel chair. There has been slight improvement with regular physical therapy. Confusion and altered mental status has resolved. She has been started on gabapentin for tingling and increased sensitivity in the bilateral lower extremities.

References

Bansal LR, Zinkus T. Osmotic Demyelination Syndrome in Children. Pediatr Neurol. 2019;97:12‐17. doi:10.1016/j.pediatrneurol.2019.03.018
 
Donnelly H, Connor S, Quirk J. Central pontine myelinolysis secondary to hyperglycaemia. Pract Neurol. 2016;16(6):493‐495. doi:10.1136/practneurol-2016-001389
 
Fasano A, Cavallieri F, Mandrioli J, Chiari A, Nichelli P. Central pontine myelinolysis and poorly controlled diabetes: MRI’s hints for pathogenesis. Neurol Sci. 2018;39(1):193‐195. doi:10.1007/s10072-017-3117-0
 
Kamath M, Manjunath S. Idiopathic Central Pontine and ExtrapontineMyelinolysis in a Child. J Pediatr Neurosci. 2019;14(2):97‐99. doi:10.4103/jpn.JPN_158_18