Title: Successful Use of Repetitive Transcranial Magnetic Stimulation for Treatment Resistant Depression
– A Case Study
Authors: James Hofmeister, OMSIII; Kishore Varada, MD, PA-C
Introduction
Treatment resistant depression (TRD) is a subclass of major depressive disorder (MDD) in adults, defined as MDD that has had inadequate response to two courses of treatment of appropriate duration. Research indicates that successive failures of pharmacologic treatment predict lower rates of remission. However, new treatment modalities such as repetitive Transcranial Magnetic Stimulation (rTMS) offer promising results in TRD. Several small studies have shown significant reduction of depressive symptoms in people with TRD using rTMS.
Case Description
We present a case of a 69-year-old female with a history of MDD, generalized anxiety disorder (GAD), and hypothyroidism, who presented to the outpatient psychiatry practice for continued symptoms of depression. She has had 3 past suicide attempts, one of which was near completion. The patient also participated in cognitive behavioral therapy without success. Additionally, the patient has tried many different courses of pharmacotherapy with either no or inadequate response. She continues to have significant symptoms of MDD and GAD. The patient was diagnosed with TRD and determined to be a good candidate for rTMS. At the onset of treatment, her Personalized Healthcare Questionnaire (PHQ-9) score was 19 and Generalized Anxiety Disorder-7 (GAD-7) was 18. She was prescribed 25 treatments of rTMS targeting the left dorsal lateral prefrontal cortex (DLPC) over the course of 5 weeks. At the conclusion of her therapeutic course, her PHQ-9 and GAD-7 were both 0. The patient was able to achieve remission of her TRD at the conclusion of her treatment despite multiple previous pharmacological treatment failures and continues to be followed by the clinic.
Discussion
This case illustrates the need to consider non-pharmacological treatment modalities for TRD. This patient has had severe depression for many years; however, she has had a robust response to rTMS. While this case shows promising results, further studies must be done to study rTMS’s efficacy. One review found only two articles specifically examining the use of rTMS in TRD, but both have shown positive results. Barriers to widespread use include cost as well as time commitment from the patient, rTMS treatment requires treatments five days a week for 4-6 weeks almost an hour long each to achieve best results.
Thank you for presenting an interesting case report. It seems this treatment modality need significant more research. Typically, how long are rTMS treatments effective? Weeks? Months? Years? Do patients typically need repeat rTMS treatments?
Hello Jami,
Thank you for your question! Among patients that initially respond to rTMS treatment, one metanalysis showed that 50% of patients continued to show response at one year https://pubmed.ncbi.nlm.nih.gov/30344109/#:~:text=Conclusions%3A%20rTMS%20is%20a%20durable,successful%20induction%20course%20of%20treatment.
Patients often receive antidepressant therapy in conjunction with rTMS, and maintenance therapy with rTMS is an area of active research.
Thank you for this interested case report, Student Dr. Hofmeister. I have been assigned as one of the judges for your project. Can you tell us more about the costs involved? Is this covered by insurance? Secondly, how does this compare to the old-school “electroshock therapy”? Thanks again.
Hello Dr. Early,
Thank you for your question! As far as the costs involved, it varies greatly. The equipment itself comes in at a variety of prices, but newer models with improved targeting are in the $25,000-$50,000 range.
Cost to the patient various considerably, and without insurance it can cost $300 or more per treatment depending on where treatment it being received. That said, with greater recognition of the efficacy of this modality of treatment, insurances are increasingly covering rTMS, especially in the context of TRD or treatment refractory depression.
As for comparison with ECT, rTMS offers similar effectiveness in non-psychotic depression according to one systemic review:
https://pubmed.ncbi.nlm.nih.gov/24556538/#:~:text=ECT%20was%20superior%20to%20high,1.11%2C%20p%20%3D%200.80). One advantage rTMS has over ECT is that it does not require the administration of anesthesia to be performed and is therefore accessible as an outpatient. procedure. Nevertheless, ECT certainly still has a role in the treatment of severe refractory depression and other complex cases of depression such as catatonic depression.
Thank you so much, Student Dr. Hofmeister. Interesting case and I appreciate your thorough response here.
Judge: Have you done a long term follow up (months to years) on the patient (or others) that includes possible adverse effects of this treatment and long term GAD and depression scores?
Hello Dr. Novack,
Thank you for your question! So far no long-term side effects have been identified using rTMS https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3260536/
The durability of the response to therapy is variable, however one metanalysis has shown that after an initial successful induction of treatment, up to 50% of patients continuing to show response at 1 year follow up:
https://pubmed.ncbi.nlm.nih.gov/30344109/#:~:text=Conclusions%3A%20rTMS%20is%20a%20durable,successful%20induction%20course%20of%20treatment. There have also been proposals to include maintenance therapy for rTMS and this is an area of ongoing research.
Thanks for your presentation. Why look for twitching of the right thumb and target that region?
Hello Dr. Walser,
Right thumb twitching will occur when the probe is accurately targeting the left DLPFC. Why this area has shown the most promise for treating depression is an area of ongoing research, however, this region of the brain is involved in executive function as well as memory. Modulating underactivity in this circuit appears to affect distant brain regions as well.
A patient’s thumb won’t twitch during stimulation at the DLPFC. Motor thresholds are measured at M1, which is 5 centimeters back from the DLPFC. The purpose of the motor threshold is to gauge what amplitude is appropriate for treatment, in lieu of neuroimaging. In other words, it’s determining the dosage with motorcortex as a visual analogue.
Some practicioners do use the position of M1 to locate an approximate treatment site at the DLPFC; in TMS this is known as the “5 centimeter rule.” However most opt for a modified F3/F4 electrode position, that can be calculated with a few cranial measurements.
Hello Alex,
Thank you for correcting my misunderstanding! This was helpful to me as well.
Thank you for your encouraging case and the response. I am intending to start TMS for TRD (trans F 60+), and formally assessed as autistic this year. Very interested in any hints with respect to concurrent improvement of executive function, and hoping for relief from MDD.