This retrospective study yielded preliminary evidence that qEEG provides excellent diagnostic performance to identify delirious patients even outside confined study environments. It furthermore revealed reduced beta power as a novel specific finding in delirium and that a normal EEG excludes delirium. Prospective studies including parameters of pretest probability and delirium severity are required to elaborate on these promising findings.

Objectives: Navigated transcranial magnetic stimulation (nTMS) provides significant benefits over classic TMS. Yet, the acquisition of individual structural magnetic resonance images (MRI individual ) is a time-consuming, expensive, and not feasible prerequisite in all subjects for spatial tracking and anatomical guidance in nTMS studies. We hypothesize that spatial transformation can be used to adjust MRI templates to individual head shapes (MRI warped ) and that TMS parameters do not differ between nTMS using MRI individual or MRI warped .Materials and Methods: Twenty identical TMS sessions, each including four different navigation conditions, were conducted in 10 healthy subjects (one female, 27.4 ± 3.8 years), i.e., twice per subject by two researchers to additionally assess interrater reliabilities. MRI individual were acquired for all subjects. MRI warped were obtained through the spatial transformation of a template MRI following a 5-, 9-and 36-point head surface registration (MRI warped_5 , MRI warped_9 , MRI warped_36 ). Stimulation hotspot locations, resting motor threshold (RMT), 500 µV motor threshold (500 µV-MT), and mean absolute motor evoked potential difference (MAD) of primary motor cortex (M1) examinations were compared between nTMS using either MRI warped variants or MRI individual and non-navigated TMS.Results: M1 hotspots were spatially consistent between MRI individual and MRI warped 36 (insignificant deviation by 4.79 ± 2.62 mm). MEP thresholds and variance were also equivalent between MRI individual and MRI warped_36 with mean differences of RMT by −0.05 ± 2.28% maximum stimulator output (%MSO; t (19) = −0.09, p = 0.923), 500 µV-MT by −0.15 ± 1.63%MSO (t (19) = −0.41, p = 0.686) and MAD by 70.5 ± 214.38 µV (t (19) = 1.47, p = 0.158). Intraclass correlations (ICC) of motor thresholds were between 0.88 and 0.97.Conclusions: NTMS examinations of M1 yield equivalent topographical and functional results using MRI individual and MRI warped if a sufficient number of registration points are used.

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