Abducens Nerve Palsy in Patient with Intracranial Hypotension After Spine Surgery

Purpose: We report a case of a patient with sixth cranial nerve palsy due to intracranial hypotension after lumbar disc surgery. Case Summary: A 56-year-old male patient complained of horizontal diplopia one day ago. He underwent disc surgery at L4-5 level 1 week ago and developed a severe positional headache postoperatively. On ophthalmologic evaluation, he was found to have 45 prism diopters esotropia of the left eye in the primary position, and left abduction was limitated and diagnosed as left abducens nerve palsy. Brain magnetic resonance imaging showed diffuse tentorial thickening and enhancement of the pachymeninges. Ultrasonography in the previous surgery site revealed fluid collection and cystic lesion. The intrancranial hypotension due to cerebrospinal fluid leakage was suspected to be the cause of abducens nerve palsy. The intravenous fluid was infused and the subdural blood patch was applied to the wound. The headache improved immediately, but diplopia lasted for about 6 months. Conclusions: Intracranial hypotension due to the cerebrospinal fluid leaks may cause abducens nerve palsy, appropriate treatment such as epidural blood patch should be considered immediately.