Aqueductal stenosis leading to herniation of the frontal horn of the lateral ventricle into the frontal sinus

Secondary adult encephalocele with abscess formation of calcified frontal sinus mucocele

INTRODUCTION

Although encephalocele is a rare congenital abnormality, secondary encephalocele is extremely rare and can cause fatal complications. Here, we report a case of secondary encephalocele caused by frontal sinus wall defect due to chronic sinusitis, which was completely removed by cranialization with autologous bone graft. A 50-year-old man with a 10-year history of chronic sinusitis visited our hospital due to suddenly altered mentality characterized by stupor. Computerized tomography scanning and magnetic resonance imaging revealed an enlarged left frontal sinus with sinusitis. The frontal sinus cavity was calcified, and the left frontal lobe had herniated into the cavity accompanied by yellow pus. A large dural defect was also found around the frontal sinus area. After removal of the abscess and some of the frontal lobe, frontal skull base repair by cranialization was performed using autologous bone graft. Streptococcus pneumoniae was cultured from the cerebrospinal fluid (CSF), necessitating treatment with antibiotics. After the operation, the mental status of the patient improved and no CSF leakage was observed.

DISCUSSION

In addition to correct diagnosis and early treatment including antibiotics, the surgical repair of defects is needed in patients with secondary encephalocele to prevent further episodes of meningitis. Surgical correction of frontal sinus encephalocele can be achieved through bifrontal craniotomy or endoscopic transnasal repair. If a patient has CSF leakage, open craniotomy may facilitate repair of the dural defect and allow for cranialization of the sinus.

CONCLUSIONS

Removal of dysplastic herniated brain tissue and cranialization of the frontal sinus may be a good option for treating secondary encephalocele and its associated complications, including meningitis, abscess formation, and infarction of the herniated brain parenchyma.

Acquired Encephalocele With Hydrocephalus and Pineal Region Epidermoid Cyst

A combination of trauma and a missed inflammatory response (nasal operation) concomitant with hydrocephalus and tumor in secondary encephalocele has not been described in the English literature yet. A 38-year-old man was admitted to the clinic with rhinorrhea that started 3 months ago. In his medical history, nothing abnormal was present except a nasal operation performed 1 year ago. Brain magnetic resonance imaging depicted left frontal encephalocele concomitant with obstructive hydrocephalus caused by an epidermoid cyst originated from the pineal region. A 2-staged surgery was planned. In the first stage, a ventriculoperitoneal shunt insertion was conveyed successfully. In the second-stage surgery, the herniated brain tissue was excised, and the frontal sinus was cleansed with serum saline combined with antibiotic. The bony defect and the dura defect were repaired. The patient's presenting complaint recovered fully, and he was discharged to home in a well condition. Acquired encephalocele is a rare entity. In case of rhinorrhea and encephalocele, even in the presence of prior history of nasal surgery, intracranial evaluation should be conveyed to exclude the presence of hydrocephalus and/or tumor. The cranial defect should be repaired to prevent future infections and brain tissue damage.

Rhinorrhoea from a frontal encephalocele after reduction of high intracranial pressure

Acquired non-traumatic frontal sinus encephaloceles are very rare lesions that are usually caused by a tumour or hydrocephalus. We present a 31-year-old woman with a frontal sinus encephalocele who developed rhinorrhoea after a ventriculo-peritoneal shunt to treat her hydrocephalus and underwent radiotherapy for a tectum tumour.

CSF rhinorrhoea due to a pulsion diverticulum of the frontal horn

We present the case of a 28-year-old man with cerebrospinal fluid (CSF) rhinorrhoea due to aqueduct stenosis and a pulsion diverticulum of the lateral ventricle into the frontal air sinus. He was successfully treated with an endoscopic third ventriculostomy and open repair of the defect.

Postoperative cerebellar herniation in a large intrapetrous aneurysmal bone cyst

An 18-year old boy presented with a tumour involving a large part of the petrous bone. A radical resection of a petrous bone 'aneurysmal bone cyst' was achieved. A large defect in the dura adjoining the posterior surface of the petrous bone was made during surgery. Post-operative MR imaging showed complete tumour resection but herniation of cerebellum into the operative defect, a phenomenon probably assisting to seal the site of cerebrospinal fluid fistula.