A Case of Miyazaki Syndrome Caused by Arachnoid Cyst-Peritoneal Shunt

Background Miyazaki syndrome is overshunting-associated myelopathy, which is a rare complication of ventriculoperitoneal shunt. We present the first case of Miyazaki syndrome caused by cystoperitoneal (CP) shunt for an arachnoid cyst (AC) in this report. Case Description We report a case of a 42-year-old man with 12-year progressive spastic paraplegia, who underwent CP shunt for an AC at the age of 15 years. Although few findings suggested overshunting on symptoms and head computed tomography, contrast-enhanced magnetic resonance imaging revealed the engorgement of the cervical spinal epidural venous plexus compressing the spinal cord. Shunt valve replacement with a pressure-adjustable valve was performed. Postoperatively, the cervical cord compression by the enlarged spinal epidural venous plexus was completely improved, but, possibly due to delayed diagnosis and treatment, the patient's symptoms only partially improved. Conclusions When patients with a history of any kind of shunt surgery develop myelopathy, Miyazaki syndrome should be suspected and, for early diagnosis, cervical and/or contrast-enhanced magnetic resonance imaging should be performed.