Introduction

Paraneoplastic neurological disorders are diseases of the nervous system that occur as a remote effect of malignant neoplasms and that are not due to infiltration of the nervous system by neoplastic tissue. These disorders have been described in association with a wide variety of neoplasms, with the lung, ovary and breast being common sites of origin. There is increasing evidence that paraneoplastic neurological disorders are due to an autoimmune attack on specific regions of the nervous system triggered by the aberrant expression of neuronal antigens by the neoplasm (Posner, 1992). Many regions of the nervous system can be involved, either in isolation or in combination, and this involvement determines the clinical features. The following paraneoplastic neurological syndromes have been described: subacute sensory neuronopathy (Denny-Brown, 1948), the Lambert–Eaton myasthenic syndrome (Eaton & Lambert, 1957), subacute cerebellar degeneration (Brain & Wilkinson, 1965), paraneoplastic motor neurone disease (Brain, Croft & Wilkinson, 1965; Henson, Hoffman & Urich, 1965), brainstem encephalitis (Henson et al., 1965), limbic encephalitis (Corsellis, Goldberg & Norton, 1968), opsoclonus and myoclonus (Brandt et al., 1974), the visual paraneoplastic syndrome (Grunwald et al., 1987), dysautonomia (Veilleux, Bernier & Lamarche, 1990), the stiff-man syndrome (Ferrari et al., 1990; Folli et al., 1993) and cochleovestibular dysfunction (Gulya, 1993).