Abstract

Paraneoplastic syndromes (PNS) involve remote effects of cancer on the nervous system. Most PNS are believed to result from an immune attack mounted against an antigen that is expressed by both cancer and the nervous system. The present study describes 3 definite cases of PNS. A 60-year-old man presented with 2 occasional epileptic seizures after he had developed subacute progressive dementia. Positive anti-Hu antibodies were detected in the cerebrospinal fluid and in the serum. The diagnosis of limbic encephalitis was supported by specific radiological findings on MRI: asymmetric hyperintensity in T2 and FLAIR sequences in the medial temporal lobes. Limbic encephalitis associated with anti-Hu antibodies indicates mainly an intrathoracic tumor. Subsequently, small cell lung carcinoma (SCLC) was diagnosed using lymph node biopsy. His MMSE score improved markedly up to 30 points after radiotherapy. A 64-year-old woman who had been operated for carcinoma papilla Vateri, presented 2 months later with double vision and nausea followed by paraparesis inferior, eye movement disorders and subacute dementia.  She died 3 weeks after admission. On the basis of clinical findings, presence of known cancer and absence of metastasis, the diagnosis of paraneoplastic encephalomyelitis (PEM) was established. In a 63-year-old woman sensory neuronopathy was diagnosed, which was evidenced by loss of sensation with relative preservation of motor power. Hilar adenopathy was revealed by a chest CT. Anti-Hu syndrome with SCLC was diagnosed. As in other paraneoplastic neurological syndromes associated with neuronal damage, sensory neuronopathy rarely improves with treatment. Paraneoplastic neurological syndromes (PNS) are immunomediated neurological syndromes triggered by an underlying neoplasm which have may been formerly diagnosed or still unknown. Neurological disorders may antedate onset of tumour symptoms by years. The main goal in the management of these disorders is early cancer treatment to achieve stabilization of PNS. Chest CT should be recommended for patients with anti-Hu syndrome, even when chest radiographic findings are interpreted as normal.