Miyazaki syndrome: Cervical myelo/radiculopathy caused by overshunting. A systematic review

Abstract

Objectives: Miyazaki syndrome is a cervical myelopathy or radiculopathy caused by cervical epidural venous congestion, due to cerebrospinal fluid over-drainage by an implanted ventricular shunt. The complex pathophysiology includes CSF pressure-changes consistent with the Monro-Kellie doctrine and a non-functional Starling resistor, leading to spinal epidural venous plexus enlargement and dilation. This venous congestion may be significant enough to exert compression on the spinal cord or nerve roots. The typical clinical and imaging findings together with a history of ventricular CSF shunting may establish the diagnosis, proven by a successful treatment. The aim of treatment is the abrogation of CSF over-drainage. The eligible interventions may be the followings: the increase of the opening-pressure of the valve system by the insertion of a new programmable valve if necessary, closing or removing the shunt.

Aim: We want to call attention to this rare iatrogenic condition with potentially severe consequences.

Patients and methods: We perform a systematic literature-review and present our five cases.

Results: Once recognized in time, Miyazaki syndrome can be well taken care of.

Conclusions: Patients with chronic ventricular shunt need monitoring for CSF over-drainage to recognise potential complications such as cervical myelopathy or radiculopathy.

Keywords: CSF over-drainage; Miyazaki syndrome; Over-Shunting myelopathy; Ventricular shunt.