Sudden Cognitive Decline in Bipolar Mood Disorder Patient with Underlying Severe Tardive Dyskinesia After the Failure of His Deep Brain Stimulation Device Battery

Bipolar disorder (BD) is a chronic mood disorder associated with multiple comorbidities. Structural and functional abnormalities in these subjects’ brains have been related to cognitive deficits correlated with the severity of the mood symptoms. These deficits are also present in euthymic states, indicating a trait characteristic. Bipolar subjects would risk developing tardive dyskinesia due to being exposed to long periods of antipsychotic treatment. Unfortunately, the presence of tardive dyskinesia is also associated with worsening cognition. One treatment option for severe tardive dyskinesia is deep brain stimulation that has also been implicated with cognitive decline. We present a case of Bipolar disorder with underlying cognitive impairment, who had a deep brain stimulation device inserted for severe tardive dyskinesia. He was admitted to a depressive phase and was noted to have a sudden worsening of cognitive impairment following his deep brain stimulation device battery running low. Possible explanations discussed for this unexpected observation are attributed to a further deterioration of his tardive dyskinesia following the device failure and depressive episode, which causes added pseudo-cognitive deficit signs.