investigated the antidepressant effects of anodal tDCS (1–2 mA) administered to the prefrontal cortex for 20 min over a course of between 10 and 20 sessions. Data from 71 cases was included in the analysis. Mood was assessed before and after an acute course of treatment using the Montgomery-Åsberg Depression Rating Scale. The following neurocognitive tests were administered prior to treatment: Simple and choice reaction time, the Symbol Digit Modalities Test (SDMT), Rey Auditory Verbal Memory Task (RAVLT), Digit Span, and the Controlled Oral Word Association Test (COWAT). Results: Better pre-treatment fronto-executive functioning, as indicated by SDMT and COWAT performance, predicted antidepres- sant response to tDCS after controlling for confounds. A cognitive composite which comprised from both SDMT and COWAT perfor- mance independently predicted better antidepressant response in an adjusted model (b = .35, p = .001). Higher depressive severity at pre-treatment was a negative predictor of antidepressant response (b = .36, p = .001). Conclusions: Pre-treatment fronto-executive functioning on mea- sures subserved by the left prefrontal cortex, the site of stimulation, is a predictor of response for tDCS treatment for depression. This study highlights the importance of inter-individual neurobiological differences in mediating tDCS antidepressant effects. doi:10.1016/j.clinph.2016.10.378 P268 Repetitive transcranial magnetic stimulation for the treatment of neuropsychiatric conditions: A systematic review and meta- analysis of cumulative cognitive effects—D. Martin a,* , S. McClintock b , J. Forster a , C. Loo a ( a University of New South Wales, Sydney, Australia, b University of Texas Southwestern, Dallas, United States) ⇑ Corresponding author. Introduction: Repetitive transcranial magnetic stimulation (rTMS) is a proven therapeutic treatment for treatment resistant depression and is in increasing clinical use throughout the world. Based upon the proven effects in depressed patients, researchers have addition- ally similarly investigated potential therapeutic effects in other clin- ical populations, for example, schizophrenia. Despite the large number of clinical trials conducted using rTMS, however, it remains unclear whether rTMS treatment additionally has cognitive enhanc- ing effects. Objectives: To determine whether therapeutic rTMS when admin- istered to the dorsolateral prefrontal cortex (DLPFC) is associated with cumulative, or lasting, cognitive improvement. Materials and methods: A systematic review and meta-analysis was conducted of randomised, sham-controlled studies conducted in patients with neuropsychiatric conditions who received therapeu- tic rTMS administered to the DLPFC. Cognitive outcomes at post treatment were pooled and examined across the following domains: Global cognitive function, executive function, attention, working memory, processing speed, visual memory, verbal memory and visu- ospatial ability. Results: Thirty-one studies met our inclusion criteria. Active rTMS treatment was not associated with generalised gains across the majority of domains of cognitive functioning examined. Secondary analyses revealed a moderate sized positive effect for improved working memory specific only to studies in patients with schizophrenia (k = 3, g = 0.507, 95% CI = [0.183–0.831], p < .01). Conclusions: Therapeutic rTMS when administered to the DLPFC in patients with neuropsychiatric conditions does not result in robust cumulative cognitive enhancing effects. However, there was a mod- erate sized effect for improved working memory in a few studies conducted in patients with schizophrenia, indicating potential speci- ficity of cognitive effects. doi:10.1016/j.clinph.2016.10.379 P269 Utility of TMS in presurgical mapping of eloquent cortices in children—S. Narayana a,b,* , K. Schiller b , F.A. Boop b,c , J.W. Wheless a,b , A.C. Papanicolaou a,b ( a University of Tennessee Health Science Center, Memphis, Pediatrics, Memphis, United States, b Le Bonheur Children’s Hospital, Neuroscience Institute, Memphis, United States, c University of Tennessee Health Science Center, Neurosurgery, Memphis, United States) ⇑ Corresponding author. Introduction: The unique ability of TMS to non-invasively induce evoked responses and virtual lesions combined with improved accu- racy afforded by image guidance has spurred its clinical applications. While the utility of presurgical motor and language mapping using TMS has been demonstrated in adults (Picht, 2013; Tarapore, 2012), its use in pediatric patients is in its infancy (Narayana, 2015). We report here, successful functional mapping of both motor and language cortices using TMS in children. Methods: Thirty-nine children (23 M, age range 0.6–18 years) undergoing surgery for brain tumors or refractory epilepsy under- went motor and language mapping using a navigated TMS system (Nexstim 4.3) (see Table 1 for the location of the lesions and type of mapping). The motor mapping (n = 22) included determination of localization and extent of primary motor cortex for hand and mouth. Language areas were localized as patients (n = 26) performed an object-naming paradigm implemented in the Nexspeech module (Nexstim Inc.) using 5 Hz TMS. TMS was applied to lateral temporal and frontal regions in both hemispheres and the observed errors were categorized using previously established criteria (Picht, 2013). Results: All patients tolerated TMS and did not experience any serious adverse effects. Motor cortex was successfully mapped in all but one patient. The TMS motor maps aided in determining the surgical approach and extent of resection in all patients (see Fig. 1- top). Language area localization and hemispheric dominance were Table 1. e142 Abstracts / Clinical Neurophysiology 128 (2017) e1–e163