Abstract
We report a case of lymphocytic primary angiitis of the central nervous system (PACNS) with a characteristic gadolinium-enhancement pattern on magnetic resonance imaging (MRI). A 48-year-old, right-handed man presented with a 3-month history of tremor and progressing dementia. Neurologic examination revealed cognitive decline with anterograde amnesia and postural tremor of the fingers. Except for the positive result of serum antinuclear antibody, intense investigations for infectious, rheumatic and neoplastic diseases were negative. Analysis of cerebrospinal fluid showed mild pleocytosis (14 cells/μl). Brain MRI revealed diffuse hyperintense areas in the deep cerebral white matter on T2-weighted images. Gadolinium-enhanced T1-weighted images demonstrated fan-shaped multiple linear enhancements converging to the body of the lateral ventricles. Brain biopsy showed intense infiltration of small lymphocytes without atypia or granuloma mainly within the vessel walls and perivascular spaces. The diagnosis of lymphocytic PACNS was made. Administration of corticosteroid markedly improved the tremor and cognitive dysfunction. MRI after the treatment showed resolution of the abnormal fan-shaped linear enhancement. He returned to his previous occupation. PACNS should be included in the differential diagnosis for fan-shaped linear enhancement converging to the lateral ventricles on MRI in patients with unexplained progressing dementia.
