[Paraneoplastic syndromes in otoneuro-ophthalmology]

The so-called neurological paraneoplastic syndromes (NPNS) are a group of diseases of the central nervous system of unknown etiology which are seen almost exclusively in patients with cancer. We review the main NPNS paying particular attention to those with ophthalmological and otological features.

Certain neuro-ophthalmological findings may constitute, at least partly, some paraneoplastic syndromes. There are alterations of vision in paraneoplastic retinopathy and in optic neuritis of paraneoplastic origin. The latter, unlike the retinopathy, usually coexists with involvement of other structures of the nervous system. Oculomotor function is affected in the opsoclonus-myoclonus syndrome. Diplopia and/or ophthalmoplegia may be a predominant or initial symptom, in patients with paraneoplastic neurological degeneration or brainstem encephalitis. In the Lambert-Eaton syndrome and in paraneoplastic encephalomyelitis, may have blurred vision and alterations of the pupil. Cases of paraneoplastic uveitis have also been described. Paraneoplastic otological involvement is less frequent. Patients with sensorineural deafness in the context of a paraneoplastic encephalomyelitis have been reported. In the NPNS vertigo is caused by cerebellar or brainstem lesions and not by lesions of peripheral organs. When nystagmus occurs in a NPNS it may be of various types and is due to involvement of structures in the brain stem or cerebellum.

The diagnosis of NPNS in patients with no known cancer is important because it may lead to the detection of an occult cancer which is localized or scarcely extended, and therefore is still potentially treatable. Oto-neuro-ophthalmological manifestations may be the first or only symptom of presentation of a paraneoplastic neurological clinical picture.