Table 4.
Research studies assessing the effects of neurostimulation in people with bulimia nervosa.
| Author | N | Sample | Treatment Type | Design | Area | Protocol | Findings | Comments | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Repetitive transcranial magnetic stimulation | ||||||||||||||||||||||||
| Gay et al. [73] | 51 | Females with DSM-IV BN Right handed |
rTMS | RCT Double-blind parallel group Conditions: (i) Real rTMS (ii) Sham rTMS |
Left DLPFC Located using 6 cm anterior method |
20 × 5 s trains/55 s inter-train interval at 10 Hz = 1000 pulses per session; 110% MT 10 sessions |
At post-treatment, no group differences in number of binges in 15 days post-treatment, features of binge episodes, number of days without bingeing, maximal craving before a binge, number of vomiting episodes and mood. | There were no within group differences from pre-to post treatment in either groups in relation to binge or purge episodes. However, within the active rTMS group there was a borderline significant (p=0.05) reduction in depression symptoms over time. | ||||||||||||||||
| Sutoh et al. [66] |
8 | Adults with DSM-IV-TR BN Right handed |
rTMS | Case series | Left DLPFC Located using 5 cm anterior method |
20 × 5 s trains/55 s inter-train interval at 10 Hz = 1000 pulses per session; 110% MT 1 session |
At 4-hours post-rTMS, a significant reduction in the subjective ratings of want to eat, urge to eat, and sense of hunger for high-calorie food stimuli was found. No effect on ED symptoms was identified. | Using near-infrared spectroscopy, haemoglobin concentration changes in the DLPFC was measured during cognitive tasks (rock-paper-scissors and food picture task), measuring self-regulatory control, both at baseline and after a single session of rTMS. A significant decrease in cerebral oxygenation of the left DLPFC was observed after a single session of rTMS. | ||||||||||||||||
| Dunlop et al. [48] |
28 | Adults (n=2 male) with DSM-5 BN (n=17) or AN-BP (n=11) Treatment non-responders |
rTMS | Case series | DMPFC Neuronavigation |
20 × 5 s trains/10 s inter-train interval at 10 Hz = 3000 pulses per session; 120% MT 20 sessions Treatment responders (n=16) received 10 additional sessions |
In whole sample, no change in binge frequency but significant reduction in purge frequency. N=16 achieved >50% reduction in binge and purge frequency (responders). |
Resting state fMRI data were collected before and after rTMS treatment to identify neural predictors and correlates of treatment response. Enhanced frontostriatal connectivity was associated with being an rTMS responder. In non-responders, frontostriatal functional connectivity was high at baseline, and rTMS suppressed functional connectivity in association with symptomatic worsening. |
||||||||||||||||
| Author | N | Sample | Treatment Type | Design | Area | Protocol | Findings | Comments | ||||||||||||||||
| Repetitive transcranial magnetic stimulation | ||||||||||||||||||||||||
| Downar et al. [68] |
1 | Adult with severe refractory BN and depression | rTMS | Case study | Bilateral DMPFC Neuro- navigation |
60 x at 5 s trains/10 s inter-train interval at 10 Hz, 3000 pulses; 120% MT 2 x 20 sessions |
Full remission of binge-purging episodes and depression for more than 2 months post-treatment completion; after a significant stressor some ED symptoms returned. These remitted after a 2nd 20 session course of treatment. |
- | ||||||||||||||||
| Van den Eynde et al. [67] |
7 | Adults with BN Left-handed |
rTMS | Case series | Left DLPFC Located using 5 cm anterior method |
20 × 5 s trains/55 s inter-train interval at 10 Hz = 1000 pulses per session; 110% MT 1 session |
Decrease in reported cravings, but mood deteriorated. | - | ||||||||||||||||
| Van den Eynde et al. [70] |
38 | Adults with BN Right handed |
rTMS | RCT Double blind, parallel groups Conditions: (i) real rTMS (ii) sham rTMS |
Left DLPFC Located using 5 cm anterior method |
20 × 5 s trains/55 s inter-train interval at 10 Hz = 1000 pulses per session; 110% MT 1 session |
Compared with sham, real rTMS was associated with a decrease in self-reported urge to eat and binge eating (24 hours post-treatment). No difference between groups in hunger, tension, mood and urge to binge eat. | An associated study in 22 participants from the same trial [71] found a reduction of salivary cortisol in patients receiving real, compared to those receiving sham rTMS. Another associated study [82] in 33 trial participants found no effect of rTMS on cognition (selective attention, assessed with a Stroop task). | ||||||||||||||||
| Walpoth et al. [72] | 14 | Female adults with DSM-IV BN | rTMS | RCT Double blind, parallel groups Conditions: (i) real rTMS (ii) sham rTMS |
Left DLPFC Neuro- navigation |
10 × 10 s trains/60 s inter-train interval at 20 Hz, = 2000 pulses; 120% MT 15 sessions over 3 weeks |
Improvement in self-reported binge-purge behaviours, depressive and OCD symptoms in both groups. No difference between real and sham groups. | - | ||||||||||||||||
| Hausmann et al. [69] | 1 | Adult with BN and depression | rTMS | Case study | Left DLPFC Neuro- navigation |
10 × 10 s trains/60 s inter-train interval at 20 Hz, = 2000 pulses; 80% MT 10 sessions over 2 weeks |
Remission from binge-purge symptoms and almost 50% decrease in depression score at post-treatment. | - | ||||||||||||||||
| Author | N | Sample | Treatment Type | Design | Area | Protocol | Findings | Comments | ||||||||||||||||
| Transcranial direct current stimulation | ||||||||||||||||||||||||
| Kekic et al. [79] |
39 | Adults with DSM-5 BN Right handed |
tDCS | RCT Double-blind crossover Conditions: (i) Active tDCS: anode left / cathode right (ii) Active tDCS: anode right / cathode left (iii) Sham tDCS |
DLPFC Located using 10–20 EEG system (F3 for left DLPFC and F4 for right DLPFC) |
2 mA; 20 minutes 1 session per condition |
Anode right / cathode left active tDCS led to reductions in eating disorder cognitions and improvement in mood, compared to the other active and sham condition. Both active conditions suppressed the self-reported urge to binge-eat. | The study also assessed temporal discounting (TD), finding that active but not sham tDCS reduced TD behaviour (was associated with more reflective choice behaviour). | ||||||||||||||||
Abbreviations: DSM - Diagnostic and Statistical Manual [74, 75]; BN - bulimia nervosa; rTMS - repetitive transcranial magnetic stimulation; DLPFC - dorsolateral prefrontal cortex; s - seconds; Hz - hertz; MT - motor threshold; ED - eating disorder; AN-BP - anorexia nervosa binge/purge subtype; DMPFC - dorsomedial prefrontal cortex; tDCS - transcranial direct current stimulation; mA - milliAmpere; EEG - electroencephalography; RCT - randomised controlled trial; OCD - obsessive compulsive disorder; TD - temporal discounting.