Extrapontine Myelinolysis in a Child: a Rare Case with MRI, DWI and MRS Follow-up

Area of Science:

• Neurology
• Pediatric Neurology
• Neuroimaging

Background:

• Extrapontine myelinolysis (EPM) is a rare neurological condition.
• EPM in childhood with extrapyramidal symptoms is exceptionally uncommon.
• Typical EPM involves the basal ganglia and brainstem.

Purpose of the Study:

• To report a rare case of pediatric extrapontine myelinolysis.
• To highlight unusual clinical and neuroimaging findings in a pediatric EPM case.
• To discuss the diagnostic challenges and implications of atypical EPM presentation.

Main Methods:

• Case report of a pediatric patient with hyponatremic dehydration.
• Magnetic Resonance Imaging (MRI) including diffusion-weighted imaging (DWI).
• Single voxel proton spectroscopy (MRS) of the basal ganglia.

Main Results:

• The patient presented with chorea and parkinsonian symptoms, indicative of pure extrapyramidal EPM.
• MRI revealed bilateral amygdala involvement, a previously unreported finding in EPM.
• Follow-up MRS showed decreased NAA and mI, while DWI abnormalities and increased ADC values appeared late.

Conclusions:

• Pediatric EPM can present with atypical extrapyramidal symptoms and novel brain region involvement.
• Delayed DWI abnormalities and increased ADC values in basal ganglia are potential indicators of EPM.
• This case expands the understanding of EPM's diverse clinical and imaging spectrum in children.