A rare case of intralesional haemorrhage of a benign aqueductal cyst after CSF diversion treatment. A case report and review of literature.

Benign cysts within the pure aqueductal region are a rare entity. Their critical location within the ventricular system presents a risk of potentially catastrophic outcomes. We present a case of a 68-year-old female who was transferred to our unit with an acute obstructive triventricular hydrocephalus caused by a benign cyst within the cerebral aqueduct. She became unconscious and had an urgent endoscopic third ventriculostomy (ETV). Post-operatively, the patient was recovering well but then developed a sudden onset severe headache accompanied by vomiting. Imaging revealed intracystic haemorrhage with expansion of lesion but there was no obstructive hydrocephalus due to CSF diversion performed 9 d prior. She was treated conservatively and continued to improve.

Tension pneumocephalus after skull base surgery. A case report and review of literature.

Pneumocephalus describes the presence of air within the cranial cavity and is often self-limiting. Tension pneumocephalus is a neurosurgical emergency manifested by headaches, seizures, reduced consciousness and even death resulting from raised intracranial pressure. Differentiating both entities clinically is often challenging but crucial. We present a case involving a sixty-year-old male who was transferred to our unit after he collapsed while undergoing rehabilitation. The patient had undergone a combined bifrontal craniotomy and transnasal endoscopic resection of recurrent sinonasal adenocarcinoma with anterior skull base involvement eight days prior. Imaging demonstrated the classic Mt. Fuji sign and a diagnosis of tension pneumocephalus was formed. The patient proceeded for definitive management which included a multi-layered repair of the anterior skull base. The three mechanisms that propose the development of tension pneumocephalus include the ball-valve mechanism, the inverted soda-bottle effect and rarely, infection from gas forming organisms. A review of current literature on PubMed/MEDLINE revealed tension pneumocephalus after skull base surgery to be a rare entity with only eleven cases reported. Most patients achieved complete recovery of symptoms post-treatment. Clinicians should recognise tension pneumocephalus as a potential complication after skull base surgery. Accurate diagnosis requires appreciation of imaging features and a high index of suspicion. Prompt management is imperative to prevent possible devastating outcomes.