Lateral Geniculate Body Lesions

    • Focal damage to the lateral geniculate body
    • Causes of unilateral lesions: neoplasm, aneurysm, vascular malformation, head trauma, neurosurgical procedures, stroke, inflammation
    • Causes of bilateral lesions: systemic hypotension, vasculitis, encephalitis, rapid correction of hyponatremia (“osmotic demyelination,” “extrapontine myelinolysis”)
    • Visual acuity is preserved with unilateral lesions but is often severely compromised with bilateral lesions
    • With unilateral lesions, complete homonymous hemianopias are most common because the lesion typically destroys the entire lateral geniculate body
    • With unilateral lesions, hourglass sectoranopia may occur following anterior choroidal artery occlusion
    • With unilateral lesions, silhouette of hourglass sectoranopia many occur following lateral choroidal artery occlusion
    • Ophthalmic manifestations may be the only clinical abnormalities
    • Brain imaging may show the lesions, but the abnormalities are often subtle
    • Unilateral homonymous hemianopias from lesions elsewhere in the retrochiasmal visual pathway
    • Perform visual fields on patients whose visual complaints are unexplained by ocular abnormalities
    • Tip: alert radiologists to the possibility of lateral geniculate body lesions in order to avoid overlooking subtle imaging abnormalities
    • Treatment outcome depends on the cause