ABSTRACT
INTRODUCTION ‘Paraneoplastic’ is a designation reserved for tumour-associated neurologic disorders that cannot be ascribed to compression or infiltration of the nervous system by tumour cells or attributed to the metabolic derangements, unwanted effects of therapy, disturbances of coagulation or opportunistic infections that potentially complicate the course and management of systemic neoplasia. Though rare, paraneoplastic phenomena compel attention because these frequently constitute the first manifestations of otherwise occult tumours. Paraneoplasia, furthermore, looms large in the differential diagnosis of certain symptom complexes that, in turn, have come to be associated with offending cancers of relatively restricted types. Thus, 60-70 per cent of patients developing the Lambert-Eaton myasthenic syndrome harbour small-cell carcinomas of the lung,13 whereas over 50 per cent of women presenting with subacute pancerebellar dysfunction will be found to have adenocarcinomas of mullerian or mammary duct origin.66 Paraneoplastic injury may affect any division of the central or peripheral (including autonomic) neuraxis and often proves a greater threat to the patient than its inciting tumour, which is often relatively confined on discovery and which may remain in abeyance even as neurological symptoms progress to devastating disability.
