Background: Syringomyelia rarely accompanies hydrocephalus except for the cases with Chiari malformation, and the efficacy of endoscopic third ventriculostomy for this entity is undetermined. Case Report: A 55-year-old man developed sensory disturbance and discrete movement disturbance on the bilateral upper limb during the past 3 years. On admission, he presented with slight tetraparesis and hyperreflection on his lower limbs with rectovesical dysfunction. Preoperative MR imaging demonstrated marked enlargement of the lateral ventricles as well as the third and fourth ventricle due to obstruction of the foramens of Luschka and Magendie. Spine MR imaging showed longitudinal dilatation of the central canal from the cerebrospinal junction toward the thoracic level with communication to the fourth ventricle, whereas Chiari malformation and tight cisterna magna were absent. He was successfully treated by ETV. The patient significantly recovered from his symptoms postoperatively, and MR imaging after surgery showed apparent shrinkage of the syrinx as well as the ventricles. Conclusion: The efficacy of the normalization of cerebrospinal fluid circulation and subsequent improvement of the syringomyelia in the present case may suggest that ETV could be a therapeutic choice for syringomyelia associated with hydrocephalus due to the obstruction of the foramens of Luschka and Magendie, especially when the connection between the ventricular system and the dilated central canal is evident, and may give a clue to the explanation for Gardner's hydrodynamic theory.
- Endoscopic third ventriculostomy
- Hydrodynamic theory