Reversible Progressive Multiple Cranial Nerve Paresis in the Isolated Fourth Ventricle following Placement of Fourth Ventricle Shunt: Case Report and Review of the Literature

Background/Aims: Multiple lower cranial nerve paresis occurring after placement of a fourth ventricle shunt for an isolated fourth ventricle is an uncommon complication in the postoperative period. Of the various etiologies, direct brain stem injury by the catheter and rapid decompression of the fourth ventricle by the shunt causing traction on the cranial nerves have been reported in the literature. Methods: We report the case of a 9-year-old girl with an isolated fourth ventricle who developed bilateral facial and multiple lower cranial nerve paresis with bilateral internuclear ophthalmoplegia a month after placement of a ventriculoperitoneal shunt. The postprocedure MRI showed a well-decompressed fourth ventricle with catheter tip located along the long axis of the fourth ventricle. Results: She was managed non-operatively. She improved gradually in her cranial nerve paresis over the next 3 months and completely recovered at 9 months. Conclusion: We believe the reversible multiple cranial nerve neuropathies resulted from acute decompression of the fourth ventricle following the shunt insertion. A gradual decompression of the dilated fourth ventricle by an aqueductal stent or a high-pressure shunting system could prevent this potential complication.