FIG 4. A, Coronal specimen from an 88-year-old woman shows blurring of the three layers: external sagittal stratum or the optic radiation (E), internal sagittal stratum (I), and tapetum (T). All three layers are pale relative to adjacent white matter. Infarcted area is also observed at the superior periventricular white matter (arrowhead). LV indicates lateral ventricle; C, medial occipital cortex. Klüver-Barrera method, original magnification x 4.

B, Coronal specimen from a 73-year-old man shows loss of distinction between the external sagittal stratum or the optic radiation and the internal sagittal stratum (arrows). This area is pale relative to adjacent white matter. Patchy pallor lesions are also observed in the white matter adjacent to the external sagittal stratum (arrowheads). LV indicates lateral ventricle; C, lateral occipital cortex. Klüver-Barrera method, original magnification x 4.

C, Coronal specimen from a 79-year-old man shows thinning of the three layers: external sagittal stratum or the optic radiation (E), internal sagittal stratum (I), and tapetum (T). LV indicates lateral ventricle; C, medial occipital cortex. Klüver-Barrera method, original magnification x 4.