The Mayo Clinic explains: “Paraneoplastic syndromes […] are rare degenerative disorders triggered by the immune system response to a cancerous tumour (neoplasm), most commonly from lung, ovarian or breast cancer or lymphoma.”
They occur when cancer-fighting antibodies or white blood cells mistakenly attack normal cells in the nervous system, causing ataxia.
“Ataxia can appear months or years before the cancer is diagnosed,” adds the Mayo Clinic.
“An infected area (abscess) in the brain may cause ataxia. A growth on the brain, a cancerous (malignant) or non-cancerous (benign) tumour, can damage the cerebellum.”