Life-threatening posterior fossa cyst induced by pseudomeningocele after operation for acoustic neuroma

Abstract

Background:Pseudomeningocele is the term used to describe fluid accumulation due to the leakage of cerebrospinal fluid into the surrounding soft tissue. It may cause complications such as cosmetic deformities, chronic meningitis, and/or impingement on vital structures resulting in neurological deficits; nevertheless, life-threatening posterior fossa cyst formation is a rare event.Case Description:We report a case of posterior fossa cyst formation induced by pseudomeningocele with brain stem compression leading to coma with pupillary dilation. These symptoms occurred after an operation for left acoustic neuroma. After emergent decompression and dural repair, the patient recovered well without experiencing any further neurological deficits.Conclusion:We discuss the clinical features, possible pathophysiological mechanisms, and treatment options for pseudomeningocele. Although most cases of pseudomeningocele follow a benign course and need only conservative treatment, the potential attendant complications, such as an enlarged cyst, may still have fatal consequences. We believe that it is beneficial to take an aggressive attitude toward this condition and to consider the possibility of surgical interventions more seriously.

Symptomatic Cerebellar Cyst Formation after Foramen Magnum Meningioma Removal: A Case Report

“…These reports, similarly to ours, concluded that dural defects and small tears in the arachnoid and parenchyma of the cerebellum affect the one-way valve mechanism, causing CSF to accumulate in the cyst. 3,4,8,9 This emphasizes the CSF connection between the pseudomeningocele and the cyst, similar to our case.…”

“…7 In our case, pseudomeningocele occurred postoperatively, a rare event since postoperative incidence is reported as 4.5% after neurological procedures. 3 These lesions are primarily occipital, with few supratentorial lesions reported. Pseudomeningocele formation is mainly from inadequate closure of the dura mater 8 that allows extradural accumulation of CSF and cystic enlargement.…”

“…Additionally, if a pseudomeningocele occurs, they often improve with conservative treatments, such as compression dressings, and rest to keep the head elevated but intractable cases may require needle aspiration or lumbar drainage. 3 However, lumbar drainage should be performed cautiously because Manley and Dillon 10 reported that cerebellar cysts might form after lumbar drainage, worsening the condition. Surgical treatment is indicated if the pseudomeningocele becomes large enough to cause neuropathy.…”

“…While pseudomeningocele can be symptom-atic, causing cosmetic problems, meningitis, or compression of the brain/nerve tissue, most cases are asymptomatic. 3 Postoperative cyst formation in the brain parenchyma is a rare complication, 4 particularly in the cerebellum, and the formative mechanism is unknown. Here, we report a case of life-threatening cerebellar cyst formation after foramen magnum meningioma removal in which a pseudomeningocele in the posterior neck area formed postoperatively and appeared to associate with cyst formation.…”

Spontaneous resolution of postoperative giant frontal pseudomeningocele

“…[ 2 3 4 5 6 ] Besides inducing anxiety to patients and their families, these lesions may cause cosmetic deformity, wound dehiscence, CSF leak, intracranial hypotension, aseptic meningitis, and even death. [ 7 8 ] Hydrocephalus, poor surgical closure of the dura, and subarachnoid scarring have all been implicated as potential contributing factors. [ 2 ]…”