[Paraneoplastic opsoclonus-myoclonus syndrome].

Area of Science:

• Pediatric Neurology
• Neuro-oncology
• Immunology

Background:

• Opsoclonus-myoclonus syndrome (OMS) is a rare neurological disorder with opsoclonus, myoclonus, ataxia, and behavioral disturbances.
• It can arise in children due to immunopathological processes linked to infections or cancers, potentially causing lasting neurological deficits.
• Paraneoplastic OMS, associated with underlying malignancy, presents diagnostic challenges due to its varied and evolving clinical manifestations.

Purpose of the Study:

• To present a ten-year observational case study of paraneoplastic OMS in a child with neuroblastoma.
• To illustrate the diagnostic challenges posed by the gradual development of OMS symptoms.
• To highlight the effectiveness of a comprehensive treatment approach.

Main Methods:

• Longitudinal case observation over ten years.
• Clinical assessment including neurological examination, ataxia, and eye movement evaluation.
• Diagnostic workup for underlying malignancy (neuroblastoma).
• Treatment modalities included surgical tumor resection, immunosuppressive therapy, nootropic, and anticonvulsant medications.

Main Results:

• The patient presented with initial symptoms of cerebellar ataxia and psychoemotional disorders, later developing opsoclonus, confirming OMS diagnosis.
• The case demonstrated a unique combination of opsoclonus with symptomatic epileptiform seizures.
• Multimodal treatment resulted in condition stabilization, regression of cerebellar symptoms, and improved mental development rate.

Conclusions:

• The gradual manifestation of OMS symptoms can delay diagnosis of the underlying paraneoplastic cause.
• An interdisciplinary diagnostic approach is crucial for cases of cerebellar ataxia, myoclonus, and abnormal eye movements, considering oncological pathology.
• Timely diagnosis and integrated treatment of paraneoplastic OMS can lead to significant clinical improvement and recovery.