[Steroid responsive anti-Hu-associated paraneoplastic encephalitis with bilateral frontal lobe lesions].

: A 46-year-old woman was admitted to our hospital because of behavioral changes. Her mentality was fluctuating vigorously and neurological examination revealed disorientation and word finding difficulty. MRI demonstrated bilateral frontal and right temporal lesions. Cerebrospinal fluid examination showed predominantly lymphocytic pleocytosis. Brain biopsy disclosed inflammation but not neoplasm. Repeated steroid therapy gave her a recovery in neurological manifestations and MRI findings. As we got a positive result of anti-Hu antibody after her complete recovery, we did screening for tumors and found small cell lung cancer. She got a chemotherapy and remains free of relapse of any symptoms. There have been few reports in that anti-Hu associated paraneolastic syndrome showed steroid responsive frontal lesions. We suggest that anti-Hu associated paraneoplastic encephalitis should be considered for steroid responsive encephalitis with brain lesions other than limbic system, because early detection of paraneoplastic encephalitis and timely antitumor treatment are important for patient's prognosis.