A case of limbic encephalitis with positive anti-zinc finger protein 4 antibody and anti-Hu antibody / 中华神经科杂志

A case of limbic encephalitis with positive anti-zinc finger protein 4 (ZIC4) antibody and anti-Hu antibody was reported. A middle-aged female was admitted to hospital for two months because of memory loss and unstable walking. The main manifestations were cognitive decline, ataxia and sensory disturbance of both lower extremities. The main diagnosis was limbic encephalitis, complicated with subacute cerebellar degeneration and subacute sensory neuron disease, which was consistent with paraneoplastic nervous system syndrome. Magnetic resonance imaging showed abnormal signals in bilateral temporal lobe and hippocampus, electromyography showed sensory nerve damage, blood and cerebrospinal fluid anti-ZIC4 antibody and Hu antibody were both positive, and no tumor was found. It is speculated that there may be potential tumors and need to be followed up and monitored. This rare case is reported to attract the attention of clinicians.

Paraneoplastic Syndrome

Paraneoplastic syndrome is a rare neurologic disorder caused not by the direct invasion or metastasis of cancer, but by the remote effects of cancer. The central- and peripheral-nervous system or neuromuscular junction area were involved in this syndrome. The pathogenesis was thought as the autoimmune disease, the result of an immunologic response to cancer and to cross-react with self-cells of the nervous system or of the neuromuscular junction, causing neuronal dam-age. Specific forms of this syndrome are often associated with specific paraneoplastic autoantibodies and cancer. The onset of neurological symptoms and detection of these antibodies often precede the diagnosis of the cancer; therefore, detection of these antibodies greatly assists the diagnosis of this syndrome and prompts investigations for the underly-ing cancer. Some paraneoplastic central neurological syndromes, such as cerebellar degeneration, limbic encephalitis, and necrotizing myelitis, were not improved by putative pathogenic autoantibodies, or by immunosuppresant or tumor removal, inspite of improvement in other peripheral neurologic syndrome, Lambert-Eaton myasthenic syndrome, neu-romyotonia, and Stiff-man syndrome. A more detailed understanding of the relationship between the cancer and the neural involvement from the molecular biological standpoint may lead to rational tumor therapy and elucidation of the mechanism of neural death. Here, major clinical forms with well-known antineuronal antibodies and specific cancers are reviewed.

A Case of Anti-Hu Associated Paraneoplastic Subacute Sensory Neuronopathy

Subacute sensory neuronopathy usually occurs as a paraneoplastic syndrome, occurring most frequently in small cell lung cancer. We report a 63-year-old male presenting typical symptoms of subacute sensory neuronopathy. Electrophysiologic studies showed diffuse sensory axonal degeneration and anti-Hu antibody was positive in his serum. We reevaluated pulmonary lesions formerly diagnosed as active pulmonary tuberculosis. Chest computed tomography showed two nodules and hilar lymphadenopathy, and by percutaneous needle biopsy, small cell lung cancer was diag-nosed.