[Trans-synaptic retrograde atrophy of the optic nerves: a differential diagnostic problem of expansive intracranial processes].

Trans-synaptic retrograde atrophy (trans-synaptic degeneration) is a secondary degenerative reaction that can appear in various areas of the brain. Degeneration of the optic radiation, the optic tract and the optic nerve due to a cerebral lesion in the occipital region has been described since the last century as a result of faetal or early childhood lesions of the brain (porencephaly, hydrocephalus) and as various cortical lesions and injuries of the occipital pole. In addition to homonomus defects in the visual fields descending partial atrophy of the optic nerves appeared after a few years in some rare cases. In this paper a two-year follow-up of a fourteen-year-old girl with trans-synaptic degeneration of both optic nerves due to a porencephalic cyst in the left parieto-occipital region is presented. In the clinical picture, apart from headache, dynamic changes of the visual fields as a result of the changes in the volume of the cist were dominant: from a right homonomus hemianopia to a right upper homonomus quadrantanopia. The differential diagnosis of this relatively rare condition is discussed, especially of expansive intracranial processes.