Microvascular Decompression of the Optic Nerve for Paroxysmal Phosphenes and Visual Field Deficit.

Abstract

Microvascular decompression surgery is standard neurosurgical practice for treating trigeminal neuralgia and hemifacial spasm. Most other cranial nerves have been decompressed for paroxysmal intermittent hyperactivity of the affected cranial nerve or in very long-standing compressions to treat cranial nerve hypofunctioning. We describe a case of intermittent paroxysmal unilateral phosphenes (i.e., light flashes) associated with worsening visual field defects. Magnetic resonance imaging showed a sandwiched optic nerve/chiasm between an inferior compression of the internal carotid artery and a superior compression of the anterior communicating artery. The patient was successfully treated by microvascular decompression and anterior clinoidectomy plus optic canal unroofing. This case report adds to the few previous case reports combining 2 previously described techniques (i.e., microvascular decompression and anterior clinoidectomy plus optic canal unroofing).