[Cotard-syndrome associated with Hashimoto encephalopathy: a case report].

There is a growing body of data on encephalopathy-related psychiatric syndromes in the literature, however, clinical management of them still remains a great challenge. Although organic background of the rarely identified Cotard-syndrome has been reported in numerous pathological states, Hashimoto-encephalopathy has not been published in association with this clinical phenotype so far. In this paper we present a case of a 44 year old woman, who previously never had a psychiatric disorder and her clinical symptoms corresponded to Cotard II syndrome. She produced psychotic depression with nihilistic doxasmas related to shutting down, clogging and rotting of her organs. These psychiatric symptoms were accompanied by cognitive, motor and vegetative signs, therefore we systematically excluded all organic brain disorders described in the literature. Besides the bizarre mental symptoms we found significantly increased anti-TPO levels in her serum, aspecific pathological signs on scull MR scans and thyreoid disease in the medical history. After differential diagnostic analyses we diagnosed Hashimoto-encephalopathy (HE), which was confirmed by positive clinical response to steroid therapy. Certain forms of HE (also named as steroid-responsive encephalopathy associated with autoimmune thyreoiditis, SREAT) are frequently associated with psychiatric syndromes but Cotard-syndrome has not been described so far in relation with this disease. This case raises attention on the significance of autoimmune diseases in the pathomechanism of psychiatric disorders and further highlights the importance of interdisciplinary diagnostic methods in the psychiatry.