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Background: A porencephalic cyst is a cavity within the cerebral hemisphere, filled with cerebrospinal fluid, that communicates directly with the ventricular system. It is a rare condition probably caused by vascular occlusion resulting from an insult during fetal development or an injury occurring later in life. Porencephaly is often associated with various ophthalmic and neurologic signs, including visual-field defects, abnormal pupillary responses, optic nerve hypoplasia, decreased vision, nystagmus, strabismus, hemi-inattention, seizures, and mental deficiencies., Case Reports: Two cases are presented of patients in whom porencephalic cysts developed as a result of traumatic head injuries. Both had demonstrable visual-field defects, with diagnosis of porencephaly verified by computed tomography scans of the head., Conclusions: Visual-field defects resulting from porencephalic cysts can mimic those observed with strokes or brain tumors. A thorough case history and complete neurologic workup can assist with differential diagnosis. The clinical features of porencephaly, different theories of brain recovery after trauma, and treatment options are discussed.

Background: Colloid cyst of the third ventricle has rarely been reported in the ophthalmic literature. The incidence is about one per 1000 in asymptomatic patients and accounts for 0.55 to 2 percent of all intracranial tumors. Although it is an uncommon benign tumor, nearly half of symptomatic patients present with papilledema and hydrocephalus. Consideration of this intracranial tumor should be included in the differential diagnosis of papilledema and apparent unilateral disc edema., Methods: A patient with highly asymmetrical papilledema and vague visual symptomatology involving the right eye was studied. Computer axial tomography (CT) without contrast enhancement revealed a colloid cyst of the third ventricle. Typical symptoms of the condition include headaches, nausea, vomiting, visual obscuration, transient diplopia and weakness of the lower extremities, which are due to acute hydrocephalus caused by increased intracranial pressure from cystic obstruction of the foramen of Monro. Intermittency of symptoms is characteristic of this lesion., Results: The patient underwent frontal craniotomy with total tumor excision and reopening of the cerebrospinal fluid pathway., Conclusions: Colloid cyst of the third ventricle discovered incidentally on CT in asymptomatic patients with no evidence of hydrocephalus can be monitored periodically. If symptomatic, neurosurgery is usually indicated since prolonged increased intracranial pressure can lead to mental and physical deterioration as well as sudden death.

Abstract: Background: The lateral geniculate nucleus (LGN) is the site at which ganglion cell axons of the optic tract synapse with neurons that form the optic radiations. Lesions of the perigeniculate visual pathway are characterized by distinct pupillary, visual field, and ophthalmoscopic findings. Such findings, combined with results from neuroimaging, enable one to precisely locate the area of the visual pathway that is involved. Case report: A patient who presented to our clinic with a complaint of narrowly missing several motor vehicle accidents recently was found to have a left horizontal sectoranopia on a screening visual field. Magnetic resonance imaging confirmed the presence of an old infarct involving the optic radiations. The patient’s medical history was significant for high homocysteine levels that likely contributed to his having had several cerebral vascular accidents in the past, one of which affected the optic radiations. Conclusions: Damage to the LGN and optic radiations can produce sectoranopic visual field defects. Although it may not be possible to specify the exact location of a lesion, understanding the blood supply of the visual pathway and retinotopic organization of the LGN aids in the localization of infarcts that cause characteristic visual field defects. [Copyright &y& Elsevier]