Hashimoto's encephalopathy presenting with bipolar affective disorder

We report on a rare case of Hashimoto's encephalopathy associated with a bipolar affective disorder.

A 32-year-old woman presented with a bipolar affective disorder and Hashimoto's thyroiditis. Neurological investigations (magnetic resonance imaging of the brain and cerebrospinal fluid) did not reveal any pathological findings except for a pathological electroencephalogram (EEG). Despite consequent antidepressant treatment, the patient remitted only in conjunction with normalization of the EEG after short-term treatment with high doses of prednisolone.

In treatment resistant courses of disorders, the thorough clinical and laboratory investigation of our patient revealed a very efficient treatment strategy. Cases of Hashimoto's encephalopathy associated with the occurrence of a manic episode and hence with bipolar disorder are rare; this is the first reported case. However, clinicians should be alert to this possibility.