Abstract

OMAS is rare affecting 1 in 10 million people per year. Symptoms include rapid, involuntary, multidirectional conjugate eye movements, brief involuntary movements of muscles and truncal/appendicular cerebellar ataxia. The combination of its rarity and postulated aetiology pose a clinical challenge. Two young healthy male patients, presented 3 weeks following an upper respiratory tract infection with demonstrable opsoclonus, widespread involuntary myoclonus and appendicular ataxia. Screening investigations including MRI brain, CT chest, abdomen and pelvis, ultrasound testicles and PET scan were unremarkable in both. Blood tests showed evidence of previous exposure to Varicella Zoster virus and Epstein Bar virus in both men. In one patient syphilis EIA (RPR non reactive, TPPA negative) and hepatitis B core antibody were detected but surface antibody was >1000 μ/ml (consistent with previous hepatitis B infection but not a carrier). Cerebrospinal fluid in both contained a high protein content. Both men received intravenous immunoglobulins, clonazepam for the myoclonus and intensive neuro-rehabilitation, making a complete recovery within 3 months and returning to full time employment. These cases illustrate symptomatic improvement following intravenous immunoglobulins, supporting its role as a therapeutic intervention as part of a multidisciplinary approach. Recognition of this syndrome is paramount to instigating treatment and aiding recovery.