Permanent visual loss after shunt malfunction

Abstract

Fourteen (1.8%) of more than 800 children evaluated in a Visually Impaired Program over 10 years became permanently blind during an episode of raised intracranial pressure secondary to shunt malfunction. Visual symptoms and papilledema were recognized in only three children at the onset of blindness. Clinical and radiologic findings suggested that the loss of sight was caused by a lesion in the pregeniculate pathway in nine patients, probably due to ischemia; five children in the postgeniculate group sustained infarcts of the occipital lobes. These cases highlight the importance of parent education and prompt treatment of raised intracranial pressure due to shunt malfunction.

Visual Disturbance Following Shunt Malfunction in a Patient With Congenital Hydrocephalus

“…The network of small arteries passing over bone, which supplies the intracranial optic nerve, is compressed by generalized high pressure and can cause circulatory stasis and ischemia. 3,6,7) Enlarged third ventricle can bulge the infundibulum downwards, pressing the posterior angle of the chiasm. 3,6,7) In the present patient, CT on admission showed enlargement of the ventricle in comparison with the CT scan taken 8 days earlier, but the ventricular dilation was not prominent enough to compress the intracranial small arteries or optic nerves.…”

“…11) Prompt treatment of increased ICP is important. 3) Early diagnosis and shunt revision may allow visual recovery. 6,7,12) …”

“…A 10-year study of a Visually Impaired Program revealed that 1.8% of the children became permanently blind during an episode of increased ICP secondary to shunt malfunction. 2,3,5,7,10,11) We treated a patient with congenital hydrocephalus who experienced rapid deterioration of her vision after shunt malfunction.…”

Visual function in the brain-damaged child

“…70 Hydrocephalus can cause acute and chronic cortical visual impairment. [71][72][73] With significant dilation of the ventricles and the resulting distention of the posterior cortex, occlusion of the posterior cerebral arteries and resulting occipital cortex infarction may occur. 74 However, most cases of cortical visual impairment associated with hydrocephalus are not associated with infarction of the occipital cortex but simply dilation of the ventricles.…”

“…Long-term shunt malfunction can cause permanent cortical visual impairment. 72 Ironically, cortical visual impairment may occur following a successful shunt procedure, presumably due to too rapid correction of the elevated intracranial pressure. 75 Cortical visual impairment may occur secondary to a variety of other causes including hypoglycemia, 76 haemodialysis, 77 cisplatin therapy, 78 seizures, 79 cerebral arteriography, 80,81 malaria, 82 and neurodegenerative disorders.…”