Spongiform encephalopathy with extensive involvement of white matter.

We report a proven case of CJD with prolonged clinical course and white matter involvement which consisted of severe, widespread myelin damage in the forebrain and cerebellum but with sparing of the internal capsule. Histologically, there was status spongiosus of the involved white matter with axonal loss, proliferation of hypertrophic astrocytes and scattered and perivascular foamy macrophages. White matter lesions have not been considered to be a significant feature of CJD. In the last few years, however, a few cases have been described with prominent degeneration of cerebral white matter. We believe that our findings corroborate the existence of an entity that at present may only be defined as spongiform panencephalopathy.