gms | German Medical Science

Objective: Over-shunting associated myelopathy (OSAM) is a very rare complication of ventricular shunt therapy, and only 11 previous cases have been reported in the literature. We report the successful surgical management of a case of OSAM in a patient with bilateral jugular vein occlusion and congenital hydrocephalus.

Methods: A 45-year-old-patient with shunt-dependent, congenital hydrocephalus presented with an 8-year history of progressive tetraparesis and gait disturbance with worsening symptoms in the last 5 months in our department. The patient was wheelchair-dependent. A new magnetic resonance imaging (MRI) scan of the head revealed slit ventricle syndrome and dural enhancement due to shunt overdrainage. An MRI and a CT-phlebography of the cervical spine revealed engorgement of the epidural venous plexus with secondary compression of the spinal cord and myelomalacia.

Surgery was performed during which we implanted a shunt valve (proSA) with the pressure level set at 26 cmH2O and a gravity-assisted unit.

Results: The patient recovered from surgery without any new deficits. The tetraparesis improved during the inpatient hospital stay and a CT-phlebography was performed 5 days after surgery. The epidural venous plexus anterior to the cervical spinal cord had returned to normal size. The patient was discharged on day 5 after implantation of the shunt valve.

Conclusion: In summary, OSAM has to be considered according to the Monro-Kellie doctrine and is affected by an engorgement of the epidural cervical venous plexus, which can produce cervical myelopathy. Since OSAM can be treated easily by increasing shunt resistance, surgeons should be aware of the rarely detected overdrainage complication.