Neuro-ophthalmology and paraneoplastic syndromes

To describe the neuro-ophthalmological manifestations of paraneoplastic syndromes and their immunological associations.

Neuro-ophthalmological signs and symptoms are usually present in paraneoplastic syndromes of the central nervous system. Unlike opsoclonus, less characteristic eye movement abnormalities are difficult to recognize as presenting symptoms of paraneoplastic syndromes. In this setting, the detection of several antibodies, including anti-Hu, Yo, Ma2, Ri, Tr, CV2/CRMP5 or voltage-gated calcium channel antibodies may help to establish that the neuro-ophthalmological disorder is paraneoplastic. Among the recently characterized antibodies, those against the Ma proteins often associate with brainstem encephalitis and vertical gaze paralysis. A small subset of patients with opsoclonus and ataxia harbor anti-Ri antibodies. In other patients, there is preliminary evidence that the autoantigens of opsoclonus reside in the postsynaptic density, but no dominant antibody marker has been identified. Uveitis and optic neuritis are rare accompaniments of paraneoplastic encephalomyelitis; some of these patients harbor anti-CV2/CRMP5 in association with other antibodies. Studies on paraneoplastic retinopathy indicate that immunity to retinal proteins other than recoverin can result in a similar syndrome to that associated with recoverin antibodies, and that melanoma-associated retinopathy may associate with several retinal antibodies.

There is increasing recognition of an extensive variety of neuro-ophthalmological abnormalities as manifestations of paraneoplastic syndromes and of several antineuronal antibodies as clinical markers of these disorders. Basic immunological studies support the pathogenic role of some of these antibodies, and are elucidating the pathogenic mechanisms that underlie these and other antibody-associated paraneoplastic syndromes.