The cerebellopontine angle (CPA) is the most common location of posterior fossa tumors. Common pathologic entities in the CPA include vestibular schwannomas, which account for 10% of all primary brain neoplasms, meningiomas, and arachnoid cysts. Surgical approaches to the CPA vary depending on the tumor size, location, and preoperative neurologic function of the patient. The retrosigmoid approach is perhaps the most versatile approach, affording excellent visualization for large tumors and allowing for hearing preservation. Radiosurgery plays an increasing role in the treatment of CPA pathology due to high rates of facial nerve function preservation and tumor growth arrest.
Symptoms
- 1
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Imbalance (early symptom).
- 2
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Vertigo and tinnitus.
- 3
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Slowly progressive deafness.
- 4
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Visual symptoms (uncommon):
- a
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Diplopia due to abducens palsy
- b
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Papilledema due to raised intracranial pressure
- c
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Bruns’ nystagmus: fine rapid gaze evoked nystagmus to the side opposite the lesion, and ipsilateral low frequency and large amplitude
- d
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Other nystagmus:
- •
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Vertical nystagmus
- •
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Rebound nystagmus
- •
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Centripetal nystagmus.
- 5
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Ipsilateral corneal reflex.
- 6
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Facial weakness (occurs late).