Pneumocephalus causing oculomotor nerve palsy: A case report

Background Pneumocephalus, the presence of gas or air within the intracranial cavity, is a common finding after cranial procedures, though patients often remain asymptomatic. Rare cases of cranial nerve palsies in patients with pneumocephalus have been previously reported. However, only two prior reports document direct unilateral compression of the third cranial nerve secondary to pneumocephalus, resulting in an isolated deficit. Case description A 26-year-old male developed a unilateral oculomotor (III) nerve palsy after repair of a cerebrospinal fluid leak. The pneumocephalus was treated with a combination of an epidural drain, external ventricular drain (EVD), and high-flow oxygen. Following treatment, repeat computed tomography imaging of the head demonstrated that the pneumocephalus was progressively resorbed and the patient's deficit resolved. Conclusion In rare cases, isolated cranial nerve palsies, specifically of the third cranial nerve, can result from pneumocephalus following cranial procedures. Acute cranial nerve palsy secondary to pneumocephalus will often resolve without intervention as the air is resorbed, but direct decompression with an epidural drain and an EVD may expedite the resolution of deficits.