Objective Deep brain stimulation of the sub thalamic nucleus (STN-DBS) is an effective treatment for the motor symptoms in advanced Parkinson’s disease (PD). However, important neuropsychiatric complications have been described after this procedure, including mania, depression, impulsiveness or suicide. Acute hippomania and mania have been described in 4% to 15% of cases, mostly in the first weeks of stimulation. The occurrence of mood changes appears to be influenced by the exact stimulation target within the STN, as well as by polarity and voltage of the stimulation. Concomitant dopaminergic medication and pre-existing subsyndromal bipolar disorder may also increase this risk. Here we report two cases of mania after STN-DBS, and review the literature regarding this complication.
Method Systematic review of the literature on mania after STN-DBS for Parkinson’s disease. Detailed report of two cases of post-STN-DBS new-onset mania.
Results Case 1: 64-year-old man, with a history of depression, medicated with sertraline 100 mg id. Manic episode starting 3 days after stimulation onset. Switching from a ventromedial monopolar to a dorsolateral bipolar stimulation contact, and voltage reduction led to remission of the manic syndrome. Four weeks later the original parameters were reset due to worsening motor symptoms. This led to a recurrence of manic behavioural changes that only remitted after a new reduction of the stimulation voltage, adjustment of dopaminergic therapy, and and introduction of quetiapine 25 mg and valproic acid 1500 mg.
Case 2: 62-year-old female, with a history of depression treated with sertraline 150 mg id. Hypomanic episode manifesting on the second day of stimulation, but fully remitting after introduction of quetiapine 25 mg id and suspension of sertraline. Two weeks later the manic episode recurred. Voltage reduction, switching to a dorsolateral target and introduction of valproic acid 300 mg bid led to sustained euthermia.
Literature review: we found 21 case-reports and case-series of STN-DBS induced mania, amounting to 49 patients. Risk appears to increase with higher voltages, monopolar stimulation and ventromedial STN targets.
Conclusion Mania is an acute and serious complication of DBS-STN. Ventromedial, monopolar, high-voltage stimulation appears to increase the risk of mania, probably because of potential extension to the cortical-striatal limbic circuit. Early recognition and treatment of this complication is critical to the prognosis.