POSTERIOR FOSSA & PETROUS MENINGIOMA

Posterior Fossa Meningioma & Petrous Meningioma

Posterior fossa Meningiomas are located in the back of the head. In this session, we will discuss the posterior fossa Meningiomas located at the front part of the petrous bone (anterior petrous Meningioma), and in the back part of the petrous bone (posterior petrous Meningioma), or in the back surface of the cerebellum (posterior fossa convexity Meningioma).

Petrous Meningioma arises from the dura lining petrous bone, which is a bone structure in the head related to the hearing mechanism. Posterior fossa convexity Meningiomas arise from the meninges covering the back part of the cerebellum. These tumors can grow to a large size and they can cause compression of the brainstem, and cranial nerves, or obstruction of the CSF flow and hydrocephalus.

Symptoms

Posterior fossa convexity Meningiomas and petrous bone Meningiomas can present with headache localized in the back of the head, dizziness, hearing loss, facial numbness, facial pain, blurred vision, or double vision, balance and gait difficulties. Less commonly patients can experience swallow difficulties or voice changes. Patients with associated hydrocephalus can develop cognitive dysfunction or acute mental status change. Patients with hydrocephalus may need emergency intervention to alleviate intracranial pressure prior to tumor resection.

Treatment

Symptomatic tumors generally require surgical intervention. Older patients with small tumors can be candidates for CiberKnife Radiation Therapy or Proton Bean Radiation Therapy. Small asymptomatic tumors can be followed with surveillance MRIs

Surgical Treatment at the Meningioma Center

Option #1

Posterior petrous Meningioma, small anterior petrous Meningioma, and posterior fossa convexity Meningioma are approached through craniotomies in the back of the head. At the Meningioma Center, we have refined a modified focused posterior fossa craniotomy approach which allows accessing these Meningiomas using a small focused anatomic approach which has mostly eliminated the post-operative chronic occipital headache associated with the more traditional approaches. This approach is used for superficial tumors in the posterior fossa and small deeper tumors.

Option # 2

At the Meningioma Center, we use the transpetrosal approach for the removal of large anterior petrous Meningiomas with brainstem compression. This approach when associated with the extradural navigation concept allows for direct access to these tumors without hazardous exposure to the brain and only minimal direct manipulation or retraction of the brain tissue.

At times, a partial resection of the inner ear may be needed to facilitate unobstructed visualization of all tumor parts. The approach allows for early identification of involved cranial nerves enhancing function preservation of these important nerves. Moreover, the approach offers maximal potential for complete resection of the tumor. Our team of Ear, Nose, and Throat otologist specialists is directed involved in transpetrosal surgeries and the Treatment of these patients.

Prognosis

Treatment of posterior fossa Meningiomas and petrous Meningiomas using the focused posterior fossa craniotomies or focused transpetrosal approach enhances the greatest tumor removal and maximizes the chances of cure without tumor recurrence. Moreover, patients have the potential for returning to their lifestyle and job occupation. Small tumor parts at positions may not be resected during surgery to avoid disabling neurological defects. The post-operative residual tumor can be treated with CiberKnife Radiation Therapy or Proton Bean Radiation Therapy Multidisciplinary approach At the Meningioma Center maximizes the potential for cure or control of these complex tumors without recurrence and with preservation or recovery of function.