A case of disseminated microscopic demyelination with multifocal dystrophic calcification

We present a 47-year-old woman with a 10-year disease course consisting of episodic confusion, aphasia, psychosis, depression, migrainous headaches and seizures. There was mild elevation of protein levels in the cerebrospinal fluid, progressive cerebral atrophy, and numerous small T1 hypointensities appearing as central "holes" in the corpus callosum on magnetic resonance imaging. She eventually expired due to status epilepticus and subsequent significant respiratory complications. In the central nervous system, there was generalized brain atrophy, and patchy labeling of blood vessels by antibodies to complement component 4d (C4d) and membrane attack complex. Innumerable small patches with loss of cell bodies (neurons and glial cells in gray matter and glial cells in white matter) and demyelination were scattered throughout the brain and spinal cord. There was no cavitation and the passing axons were mostly preserved. Large solid calcified foci were present predominantly in the pons along with disseminated focal calcification involving neuron cell bodies, neurites, and capillaries. Patchy labeling of glial cells and linear structures suggestive of myelin sheaths with C4d antibodies was observed while immunostains for SV40, tau, β-amyloid, alpha synuclein, p62, and trans-activation response DNA-binding protein 43 kDa were negative. Whole-exome sequencing did not reveal any clinically significant variants. Although the radiological findings are suggestive of Susac's syndrome (a rare condition characterized by encephalopathy, hearing loss, and branch retinal artery occlusion), in the absence of audiovisual manifestations, a definitive diagnosis cannot be rendered and therefore, this case may be representing a new entity. Further reports of similar cases are needed for clarification.