Lewy body Eosinophilic cytoplasmic body with a clear halo, classically seen in pigmented neurons of the substantia nigra and locus ceruleus in Parkinson disease. Meningioma A tumor of arachnoidal cells. Leukodystrophy due to lysosomal arylsulfatase A deficiency. Microglial nodule A commonly seen feature in viral encephalitis. Multiple sclerosis Demyelinating disease characterized by multiple CNS demyelinating plaques, the multiplicity of the plaques correlates with the variability of clinical symptoms.
Optic neuritis is a common presenting symptom.
A disorder of neuromuscular transmission characterized by antibodies to the acetylcholine receptor. The clinical picture is characterized by progressive weakness with sustained effort. Thymic hyperplasia is often present and thymomas also occur. Neuritic plaque Senile plaque, composed of an amyloid core surrounded by dystrophic neurites. Diffuse plaques do not have obvious dystrophic neurites.