Baruth, Joshua

Objective: Preliminary studies suggest that repetitive transcranial magnetic stimulation (rTMS) may be an effective and tolerable intervention for adolescents with treatment-resistant depression. There is limited rationale to inform coil placement for rTMS dosing in this population. We sought to examine and compare three localization techniques for coil placement in the context of an open-label trial of high-frequency rTMS for adolescents with treatment-resistant depression. Methods: Ten adolescents with treatment-resistant depression were enrolled in an open-label trial of high-frequency rTMS. Participants were offered 30 rTMS sessions (10 Hz, 120% motor threshold, left 3000 pulses applied to the dorsolateral prefrontal cortex) over 6–8 weeks. Coil placement for treatment was MRI guided. The scalp location for treatment was compared with the locations identified with standard 5 cm rule and Beam F3 methods. Results: Seven adolescents completed 30 rTMS sessions. No safety or tolerability concerns were identified. Depression severity as assessed with the Children's Depression Rating Scale Revised improved from baseline to treatment 10, treatment 20, and treatment 30. Gains in depressive symptom improvement were maintained at 6 month follow-up visits. An MRI-guided approach for coil localization was feasible and efficient. Our results suggest that the 5 cm rule, Beam F3, and the MRI-guided localization approaches provided variable scalp targets for rTMS treatment. Conclusions: Open-label, high-frequency rTMS was feasible, tolerable, and effective for adolescents with treatment-resistant depression. Larger, blinded, sham-controlled trials are needed for definitive safety and efficacy data. Further efforts to understand optimal delivery, dosing, and biomarker development for rTMS treatments of adolescent depression are warranted.

ObjectivesThe aim of the present study was to examine N‐acetylaspartate (NAA), a general marker of neuronal viability, and total NAA (tNAA), the combined signal of NAA and N‐acetylaspartylglutamate, in bipolar depression before and after lamotrigine treatment. Given that NAA is synthesized through direct acetylation of aspartate by acetyl‐coenzyme A‐l‐aspartate‐N‐acetyltransferase, we hypothesized that treatment with lamotrigine would be associated with an increase in NAA level.MethodsPatients with bipolar depression underwent two‐dimensional proton magnetic resonance spectroscopy of the anterior cingulate at baseline (n = 15) and after 12 weeks of lamotrigine treatment (n = 10). A group of age‐matched healthy controls (n = 9) underwent scanning at baseline for comparison.ResultsAt baseline, patients with bipolar depression had significantly lower NAA [mean standard deviation (SD) = 1.13 (0.21); p = 0.02] than controls [mean (SD) = 1.37 (0.27)]. Significant increases in NAA [mean (SD) = 1.39 (0.21); p = 0.01] and tNAA [mean (SD) = 1.61 (0.25); p = 0.02] levels were found after 12 weeks of lamotrigine treatment.ConclusionsThese data suggest an NAA deficit in bipolar depression that is normalized after lamotrigine treatment. Future research is warranted to evaluate whether baseline NAA level is a potential biomarker for identifying lamotrigine response patterns and whether this functional brain change has an associated clinical response.

Proton magnetic resonance spectroscopy (1H‐MRS) is a safe, noninvasive way of quantifying in vivo biochemical and metabolite concentration levels in individuals withAutismSpectrumDisorders (ASD). Findings to date suggestASDis associated with widespread reduction inN‐acetylaspartate (NAA), creatine plus phosphocreatine (Cr), choline‐containing compounds (Cho),myo‐inositol (mI), and glutamate plus glutamine plus gamma‐Aminobutyric Acid (Glx); however, variable findings, and even substantial increases, are not uncommon depending on the study and/or region‐of‐interest. Widespread reduction ofNAA,Cr,Cho,mI, andGlxinASDlikely reflects impaired neuronal function and/or metabolism related to abnormal neurodevelopmental processes. Future studies should attempt to relate1H‐MRSfindings to histological findings and control for variability in subject age and functioning level; this would assist in evaluating the relationship between1H‐MRSmetabolic levels and neuronal and glial cell densities, as well as neurodevelopmental process associated withASD. Furthermore, more longitudinal1H‐MRSstudies are needed in both control andASDsubjects to attempt to standardize metabolite levels across different developmental periods in well‐defined endophenotypes. This will provide for a standard rubric for which metabolic aberrations (as well as treatment responses) can be measured. With higher magnetic field strengths and spectral‐editing techniques capable of quantifying less‐concentrated metabolites,1H‐MRSwill continue to be an important tool inASDresearch.Autism Res2013, 6: 119–133.© 2013 International Society for Autism Research, Wiley Periodicals, Inc.