[Leptomeningeal abnormality on Gd-DTPA enhanced MRI in a case of SLE presenting diffuse organic brain syndrome].

Involvement of the central nervous system associated with SLE (CNS lupus) is not rare. Two types of CNS lupus are noted clinically; one group manifesting focal neurological symptoms and another group showing mental symptoms. Though it is well known that neurological symptoms are caused by arteritis and thrombus, pathophysiological mechanisms leading to mental symptoms remain obscure and there is no established clinical evidence responsible for these symptoms. A 41-year-old woman was confused and her attention was markedly impaired. Her mental symptoms consisted of disorientation, restlessness, euphoria and emotional incontinence. There were neither focal neurological signs nor meningeal signs. Cerebrospinal fluid (CSF) examination showed increased number of polymorphonuclear cells and permeability of the blood-brain barrier, calculated based on the CSF/plasma protein ratio, was also elevated. Repeated bacteriological examinations revealed to be negative. Gd-DTPA MRI demonstrated diffuse enhancement of the cerebral leptomeninges. Methylprednisolone pulse therapy ameliorated her mental deterioration effectively, and subsequently the leptomeningeal enhancement with Gd-DTPA MRI disappeared in parallel. These radiological and laboratory findings suggest that SLE itself causes inflammation of vessels in the leptomeninges and adjacent cerebral cortex. We consider mental symptoms associated with SLE may be caused, at least in part, by this mechanism. To our knowledge, we could not find similar reports in the literature. Gd-DTPA enhanced MRI seems to be of clinical use for making diagnosis, evaluating clinical activity and understanding of CNS lupus.