Bifrontal Electroconvulsive Therapy in a Patient With Subcallosal Cingulate Deep Brain Stimulation for Depression
In recent years, various forms of psychosurgery have been explored as potential treatments for refractory major depressive disorder.1 Rather than ablating brain tissue, deep brain stimulation (DBS) has been shown to create a functional lesion and is therefore optimally suited as a surgical intervention for certain neurological and psychiatric conditions. Based on clinical, postmortem, and neuroimaging results, the subcallosal cingulate (SCC, also referred to as Brodmann area 25 or Cg25) is the region most thoroughly studied in treatment-refractory depression.2
Although there are reports of the safe use of electroconvulsive therapy (ECT) in patients with DBS in movement disorders, this is the first report we are aware of in a case of SCC DBS for treatment-refractory depression.
Ms B. is a 56-year-old woman with a diagnosis of severe treatment-refractory depression since 1994. Over the years, although there would be brief episodes of improvement, she had chronic neurovegetative features and suicidal ideations. She received numerous medication trials, individual cognitive-behavioral therapy, group therapy, and 5 courses of ECT until 2005 (3 of the courses continued with outpatient maintenance ECT treatments up to 1 year in duration).
In 2006, she enrolled in an open-label trial for SCC DBS for treatment-refractory depression.3 Response to high-frequency stimulation (130-Hz) DBS treatment varied through the years, but complete remission of the depression symptoms remained elusive. Because of the partial response to treatment and repeated implantable pulse generator (IPG) replacements related to battery drain, in 2014, the IPG was replaced with a Brio™ Rechargeable IPG (St Jude Medical, St. Paul, MN).
Unfortunately, despite pharmacotherapeutic adjustments, her mood state declined very significantly in 2016 after the death of a parent, supportive psychotherapy, and maintenance of optimal DBS parameters. In February 2016, she was admitted to a nonhospital residential facility and had 3 bifrontal ECT treatments. Her course had to be interrupted when she developed a right-arm axillary vein thrombosis. She was started on long-term anticoagulation therapy with rivaroxaban because of a prior pulmonary embolus in 2008.
Her mood improved temporarily but then progressively deteriorated with suicidal ideations, ultimately requiring readmission to our hospital for a full course of ECT in early 2017.
ECT was initiated following the British Columbia provincial guidelines.4 Pre-ECT workup included baseline electrocardiogram, complete blood count, differential, electrolyte panel, liver functions, and creatinine. Computed tomography of the brain scan was done prior to the ECT, which confirmed DBS placement. Beck Depression Inventory demonstrated a score in the “severe depression” range. Pre-ECT cognition screen was normal. Anesthesia consultation was obtained.
She was maintained on aripiprazole 4 mg 3 times a day, paroxetine 60 mg daily, trazodone 300 mg at bedtime, dextroamphetamine 25 mg in the morning, and 5 mg at noon through the ECT course because these medications were felt to be symptomatically helpful. Other medications included rivaroxaban (dose halved the day before and morning of ECT as suggested by hematology), hydrochlorothiazide, levothyroxine, pantoprazole, and tramadol for chronic pain.
The patient was hyperventilated with Po2 94% at 4 L/min. Methohexital 120 mg was the induction agent used with succinylcholine 50 mg as muscle relaxant for all treatments. A mouth guard was used, and the IPG was interrogated immediately pre-ECT to ensure it was turned off before treatments.
The ECT device used was a Somatics Thymatron System IV (Somatics, LLC, Venice, FL). Bitemporal electrode placement was considered, but given the patient’s subjective complaints of short-term memory deficits prior to treatment, we decided to proceed with bifrontal placement as in the 3 treatments prior to the axillary vein thrombosis with the hope of less cognitive impairment.