Neuronal Intranuclear Inclusion Disease Causing Homonymous Hemianopia

Neuronal intranuclear inclusion disease (NIID) is a rare, progressive neurodegenerative leukoencephalopathy associated with eosinophilic neuronal hyaline intranuclear inclusions. NIID is a difficult diagnosis to make, as the disease presents at varying ages, with varying inheritance patterns, and with various forms of central/peripheral/autonomic neurologic dysfunction. Previously reported ophthalmologic findings of NIID include miosis, nyctalopia, nystagmus, electroretinogram abnormalities, and retinal degeneration. Though the genetic basis for most NIID cases remains unknown, skin biopsy is sensitive for diagnosis. We report a patient who presented with visual hallucinations and a homonymous hemianopia from adult-onset NIID, which is a unique presentation.