Right Temporoparietal Junction Transcranial Magnetic Stimulation in the Treatment of Psychogenic Nonepileptic Seizures: A Case Series

Abstract

BACKGROUND Psychogenic non-epileptic seizures (PNES) may involve hypoactivity in the right temporoparietal junction (TPJ), suggesting a promising target for therapeutic neuromodulation. In this proof-of-concept case series, we aimed to investigate the tolerability and potential efficacy of high frequency repetitive Transcranial Magnetic Stimulation (rTMS) over the right TPJ to decrease non-epileptic seizure rates. METHODS Seven subjects with video-EEG documented PNES without comorbid epileptic seizures were recruited. The rTMS protocol involved thirty stimulation sessions administered twice per day over three weeks. Each session consisted of three thousand pulses of high frequency (10 Hz) rTMS applied over the right TPJ. Tolerability was monitored throughout treatment. Weekly PNES counts were recorded at baseline, during treatment, and at post treatment intervals as the primary outcome measure. Additional psychometric scales assessing dissociation and functional neurological symptoms were collected at baseline and within 1-week post treatment as secondary outcome measures. RESULTS Treatment with rTMS was well tolerated by all participants. Participants reported a decrease in weekly seizure rates post vs. pre-treatment, which was sustained at 3-month follow-up. Improvement was also reported on the Dissociative Experiences Scale and the Conversion Disorder Subscale of the Screening for Somatoform Symptoms-7 Scale. CONCLUSION High-frequency rTMS over the right TPJ represents a promising treatment for PNES that warrants additional research.

Diagnosis and management of functional neurological disorder

“…In addition to psychotherapy, evidence from RCTs supports using botulinum neurotoxin in the management of functional motor symptoms, although the mechanism of action may be related to placebo effects 233234. Emerging evidence, yet limited, supports transcranial magnetic stimulation, although it remains unclear if potential efficacy is owing to circuit-specific neuromodulation or placebo response 29235236237238. More research is needed to identify potential therapeutic roles for therapeutic sedation, botulinum neurotoxin treatment, placebo, hypnosis, and virtual reality interventions among other promising management strategies 234239240241242243…”

“…This clinical interest occurs in parallel with new research findings that show efficacy of specific therapeutic approaches,212324 and elucidate underlying neurobiological mechanisms2526 that open new routes into targeted treatment strategies 27282930…”

Neurostimulation for the treatment of functional neurological disorder: A systematic review

“… Table 1.2. Open Label Studies Parameters of stimulation Results Study (author/year) FND Phenotype Design N Anatomical Target Frequency* Intensity (% MT) Total pulses/ session # Sessions Outcome Measures Outcome Time point 1** Outcome Time point 2*** Open label Spagnolo et al [56] Movement disorder -unspecified Open label 6 Left DLPFC Individualized fMRI imaging guided iTBS 120%RMT 3600pulses total of 6 sessions 2 visits- 24h interval 3 iTBS sessions each visit, >20min between sessions Functional MRI data S-FMDRS Decrease functional connectivity between the left amygdala and DLPFCSignificant FMDRS decrease within each stimulation visit (pre and post treatment) Significant FMDRS decrease between baseline (pre TMS) and 24h after last stimulation Peterson et al [62] Functional seizures Open label 7 Right TPJ rTMS 10Hz 5 sec trains ITI 30sec 110% MT 3000pulses 30 sessions in 3 weeks 2 sessions/day-15min between sessions Functional seizures count Decrease in weekly functional seizures frequency in all subjects throughout treatment. All participants sustained improvement up to 3 months post-treatment.…”

“…Three further studies evaluated the efficacy of TMS on functional seizures. Peterson et al (2018) [62] and Agarwal et al (2019) [55] used right temporo-parietal junction (TPJ) as the anatomical stimulation target, whereas Blades et al (2020) [63] used the anterior cingulate cortex as the target. Although all three studies used different TMS protocols (rTMS excitatory, rTMS inhibitory and iTBS excitatory respectively) and different parameters of stimulation, all three reported positive outcomes with significant improvement after treatment and sustained improved in symptoms at subsequent follow-up timepoints.…”

Treatment emergent affective switch with intermittent theta burst stimulation over right temporo-parietal junction: A case report

“…rTMS was delivered using MagVenture-MagPro-R30 device with a figure-of-8 shaped coil. In view of the prominent PNES, excitatory stimulation over right temporoparietal junction (rTPJ, 1 cm lateral to CP4 electrode in the 10e20 international EEG system) was given [3]. Stimulation was delivered using iTBS administered at 80% resting motor threshold (RMT), which was determined prior to stimulation sessions.…”