The Canadian Journal of Neurological Sciences

Paraneoplastic Encephalomyelitis, Stiff Person Syndrome and Breast Carcinoma Paraneoplastic syndromes (PNS) are the rarest non-metastatic neurological complications of cancers in which no specific etiology can be identified. Among PNS, stiff person syndrome is characterized by “rock-hard” rigidity and painful spasms in distal limbs, most frequently legs, and abnormal foot and/or hand posture. General posture is rigid; ambulation is difficult and may result in falls. Paraneoplastic syndromes are postulated to be autoimmune diseases. Stiff person syndrome associated to cancer display high antibody titers directed against neuronal proteins1,2. We present the case of a woman first diagnosed with stiff person syndrome, which led to the diagnosis of an invasive ductal carcinoma of the breast. Paraneoplastic antibodies titers previously reported in literature were all negative.