nrTMS for depression
Applications: Psychiatry, neuropsychology
Non-invasive therapy for medication resistant patients
PET imaging studies in patients diagnosed with major depressive disorder (MDD) have shown lower metabolism, compared to controls, in their left dorsolateral prefrontal cortex (DLPFC) regions, which supports the concept of using TMS as a therapy to increase the excitability of the left DLPFC.
Navigation enables accurate targeting of the DLPFC. Without neuronavigation, research shows that the correct area is only targeted in approximately 30% of patients. Studies show that without navigation, treatments are unintentionally being delivered on average 2 cm posterior to the DLPFC
Nexstim NBT® System with SmartFocus® nTMS uses advanced algorithms based on mathematical modelling, taking into account both the shape and the composition of each patient’s individual brain. SmartFocus® nTMS displays the location and orientation of the maximum induced E-field in a 3D rendering, built from the patient’s own MRI head scan. The multi-sphere model has been scientifically validated to accurately determine the location and orientation of the maximum induced e-field in the brain and hence to target the stimulation to the intended spot with accuracy in the millimetre range.
Of the 208 patients who have completed Nexstim SmartFocus® rTMS treatment with Nexstim NBT® system for major depressive disorder (MDD), 50.5% were in remission at end of treatment and 76.0% had obtained a clinical response, compared to recent findings from a multi-centre study that reported 26.5-28.7% remission and 41.5-56.4% clinical response.
Similar to EnTMS motor mapping, the patient's resting threshold is determined by targeting the primary motor cortex (usually at 120% of the resting threshold).
Nexstim EnTMS enables accurate and precise targeting of the DLPFC without anatomic assumptions.
The conventional rTMS protocol involves 10hz bursts of 40 pulses (one burst is 4s duration), with one burst every 30s at an interval of 26s.
3,000 total pulses in a sequence, with total duration between 18-37 minutes.
Theta burst protocols can also be enabled however these are not reimbursable by Medicare.
Opportunity to align with the Nexstim NBT registry, to collaborate for best-practice techniques and share observations.
Hospital purchase of Nexstim NBT system
Referral for patient MRI
Consultant clinician books appointment with Neuroclast
rTMS conducted by Neuroclast with in-person or remote support from clinician
Data sent to consultant clinician for analysis
Nexstim's proprietary SmartFocus technology ensures for the most precise dosing of TMS in comparison to non-navigated alternatives. This is not simply 'navigated TMS'; this takes into consideration the 'spread' and 'direction' of the stimulation in consideration of the patient's individual cortical topographic anatomy. As the operator moves, turns or tilts the coil - even slightly - the system shows the updated location, orientation and stimulating E-field data in real time.
En-TMS conducted by Neuroclast can be included in multiple multi-centre trials throughout Australia. Consent will be sought prior to any data capture, and acquired from the patient, consultant and hospital.
Fitzgerald & Daskalatis (2013). Repetitive Transcranial Magnetic Stimulation Treatment for Depressive Disorders: A practical guide.