Pediatric whole body MRI detects causative ovarian teratoma in opsoclonus myoclonus syndrome

Abstract

Opsoclonus Myoclonus Syndrome (OMS, or Opsoclonus Myoclonus Ataxia) is a rare condition that presents with saccadic movements of the eyes, cerebellar ataxia, and choreiform movements of the limbs. While previous reports have described the use of ultrasound, CT, FDG-PET and traditional focused MRI for localization of OMS-associated masses, whole body MRI has not previously been reported for this purpose. Here we describe a 16-year-old patient who exhibited OMS and underwent whole body MRI to rule out the more commonly associated neuroblastoma. An ovarian mass was discovered, resected, and pathology confirmed benign teratoma - there was subsequent resolution of symptoms after complete surgical resection. Whole body MRI should be considered in pediatric cases of OMS due to the paraneoplastic nature of the disease with associated tumor, high sensitivity of disease detection, lack of ionizing radiation, excellent tissue resolution and demonstrated effectiveness in pediatric imaging.

Acute Movement Disorders in Childhood

“…Pediatric OMS is a paraneoplastic phenomenon related to neuroblastoma in about 50% of the cases [ 66 ], and rarer associations with ganglioneuroma, hepatoblastoma are possible [ 65 ]. In adolescents (especially females), the association of OMS, additional signs (ophthalmoparesis, dysarthria, altered consciousness) and ovarian teratoma (without anti-NMDAr antibodies) has been described as a distinctive brainstem–cerebellar syndrome [ 38 , 67 ]. Therefore, in-depth work-up for occult tumor detection is mandatory, including the testing of homovanillic acid and vanillylmandelic acid urine levels and chest, abdominal, and pelvic CT or MRI.…”

Clinical Reasoning: An adolescent girl presenting with worsening vertigo, headache, and ataxia

“…Despite the cost and length of the study, MRI was chosen over CT to limit radiation exposure to an otherwise healthy patient. 1…”