[Chorea-athetosis in the anti-Hu syndrome]

Paraneoplastic choreo-athetoses are rare. We report a case of anti-Hu syndrome with choreo-athetosis.

A 48-year-old woman developed a small-cell lung carcinoma revealed by an anti-Hu syndrome. The neurological features included choreo-athetosis predominating in the upper limbs, chronic sensorimotor axonal polyneuropathy, and opsoclonus. The cerebrospinal fluid was acellular and contained several oligoclonal IgG bands, not found in the corresponding serum. Magnetic resonance imaging revealed bilateral high-intensity lesions on T2/FLAIR sequence in the corona radiata. Moderate transitory improvement of the paraneoplastic neurological syndrome was observed after several carboplatin-etoposid cycles.

A paraneoplastic origin must be considered in all cases of unexplained choreo-athetosis. Paraneoplastic choreo-athetosis is most often associated with other neurological symptoms. The most frequent associated tumor is a small-cell lung carcinoma with anti-CRMP5 and/or anti-Hu antibodies. Our patient developed paraneoplastic choreo-athetosis related to an anti-Hu syndrome in the absence of anti-CRMP5/CV2 antibodies. Paraneoplastic choreo-athetosis might result from a central lesion, and/or from proprioceptive deafferentation subsequent to peripheral neuropathy.