Anti-Yo mediated paraneoplastic cerebellar degeneration in the context of breast cancer: a case report and literature review.

BACKGROUND: Paraneoplastic syndromes are of interest to psycho-oncologists because they may be misdiagnosed initially as primary psychiatric disorders and can have profound neuropsychiatric and psychosocial sequelae. Paraneoplastic cerebellar degeneration (PCD) is a paraneoplastic syndrome which destroys Purkinje cells of the cerebellum and causes trunk and limb ataxia, dysarthria, diplopia, and vertigo, which often precede the diagnosis of cancer. Anti-Yo PCD is a devastating syndrome that significantly worsens prognosis in terms of functional ability and survival.
METHODS: We present the case of a woman with progressive cerebellar deficits, which were misdiagnosed for several months before breast cancer and anti-Yo antibodies were discovered.
RESULTS: PCD may be misdiagnosed as a primary psychiatric disorder. Results of neuropsychological assessment in this case found subtle attentional dysfunction but relatively preserved cognitive functioning in other domains. DISCUSSION: The literature relating to PCD and psychiatric manifestations of cerebellar disease are reviewed. The limitations of our current understanding of non-motor cerebellar function are highlighted, asserting the need for further study in this area.