Louisville Medicine Volume 68, Issue 10 - Page 26

Michael R . Harris , MD & Kevin G . Bays , MD
MENTAL HEALTH

REPETITIVE TRANSCRANIAL MAGNETIC STIMULATION ( RTMS ): NEW

HOPE FOR PATIENTS WITH MAJOR DEPRESSIVE DISORDER

INTRODUCTION
Major Depressive Disorder ( MDD ) is a clinical disorder characterized by depressed mood , lack of pleasure in activities and sleep disturbances . Additional symptoms may include a constellation of symptoms such as deficits in memory and concentration , hopelessness , guilt , fatigue and suicidal thoughts or plans . In the US it is estimated that over a person ’ s lifetime , up to 25 % of the population may suffer from symptoms that meet the criteria for MDD at some time . The disorder is frequently encountered in primary care and specialist medical practices , either as a chief complaint or an auxiliary finding .
Treatments in addition to counseling for MDD have been available for decades , beginning with tricyclic antidepressants and progressing to the large number of agents of multiple classes now available . Unfortunately , some patients do not respond to pharmacological management despite multiple medication trials .
Results from the STAR * D study , a large multicenter evaluation of outpatient treatment for MDD , reveal a disappointing statistic . The likelihood of responding to repeated antidepressant trials diminishes with each subsequent trial . By the time a patient has had four antidepressant trials without success , the response rate drops to 14 % for subsequent trials . It has become clear that medication is not effective for all patients with MDD .
In the search for advanced treatments for MDD , some research has focused on direct neurological interventions rather than systemic pharmacotherapy . Direct stimulation of neurons has been used extensively for the treatment of Parkinson ’ s Disease and other neurological disorders . External magnetic field stimulation of the brain has been found effective in treating MDD . By targeting the appropriate regions of the brain which are known to show reduced activity in depressed patients , we can directly increase neuronal activity and relieve some of the symptoms of depression .
This technique , now known as repetitive transcranial magnetic stimulation ( rTMS ), has been FDA approved for the treatment of depression since 2008 . As with many innovative medical techniques , rTMS initially struggled to gain recognition among physicians ,
24 LOUISVILLE MEDICINE
Michael R . Harris , MD & Kevin G . Bays , MD
patients and third-party payers . The growth in equipment sophistication , refinement of treatment techniques , and wider acceptance has resulted in an increased availability of rTMS in recent years . The Integrative Psychiatry group has offered this therapy since 2010 , and Louisville Behavioral Health has offered TMS treatment since January 2020 . “ TMS Therapy ” is advertised by various groups with Louisville , Lexington and Radcliff locations .
Our practice employs the NeuroStar unit , focusing on the treatment of MDD . Typically , the rTMS patient has been failed by intolerable , or ineffective medicines in multiple tries . In addition , they have struggled to achieve results from psychotherapy using a standardized model such as Cognitive Behavioral Therapy ( CBT ). When patients are referred for rTMS , a review of their mental health treatment history is initiated including their history of pharmacology , psychotherapy and experience in other levels of care . The patient receives an in-person consultation from a rTMS trained psychiatrist , focusing on the past history of depressive symptoms and the response , or lack of , to the various treatments they have undertaken . A medical screening is also conducted to ensure that the patient does not have any ferromagnetic medical appliances or devices implanted within 30 cm of the treatment site . These are contraindicated for rTMS due to the risk of movement or heating of the implants .
The initial session of rTMS involves localization of the left dorsolateral prefrontal cortex ( DLPFC ), which is the target of rTMS treatment for MDD . Since this brain region does not demonstrate a physical reaction to magnetic stimulation , the left motor strip is used for localization . A single magnetic field pulse administered to this area of the brain results in a single twitch on the right side of the body . This guides our optimization of treatment by allowing us to select the correct lateral area of the cortex and the proper magnetic field strength for each individual patient .
Treatments are delivered on a daily schedule , Monday through Friday , for a total of 36 treatments . Daily appointments are about 30 minutes from time of arrival to time of departure , and symptoms begin to show improvement about halfway through the prescribed treatment course . Using standard depression rating scales , the patient ’ s symptoms are followed closely during treatment . While results can never be guaranteed , two out of three of our patients have demonstrated significant symptom improvement ; and one out of five have complete remission with this treatment . rTMS is covered by Medicare and most commercial medical insurance providers .
The availability of rTMS provides the hope of relief to patients who have previously struggled to find the right treatment for their depression . Louisville Behavioral Health is pleased to offer this advanced treatment for MDD .
Dr . Harris is a practicing psychiatrist at Louisville Behavioral Health Systems . ( non-member )
Dr . Bays is a practicing psychiatrist at Louisville Behavioral Health Systems . ( non-member )