Artikel
The spatial resolution of repetitive navigated transcranial magnetic stimulation for cortical language mapping
Suche in Medline nach
Autoren
Veröffentlicht: | 2. Juni 2015 |
---|
Gliederung
Text
Objective: Navigated transcranial magnetic stimulation (nTMS) is increasingly used for therapeutic as well as diagnostic purposes. When nTMS is applied with high frequency during an object naming task (repetitive nTMS = rTMS), it is possible to disturb language performance in the sense of causing no responses. However, the spatial resolution of this cortical mapping approach is still unknown.
Method: To determine the spatial resolution of rTMS-based language mapping, we evaluated 19 mapping sessions performed in healthy, right-handed volunteers for cortical hotspots of no-response errors. Then, the distance between the hotspot and four adjacent mapping points was measured.
Results: Overall, mapping was successfully performed in all subjects, and three hotspots were identified. Mean distance values of 13.5 ± 6.3 mm (from hotspots to ventral points, range: 0.7 – 30.7 mm), 10.8 ± 4.8 mm (from hotspots to dorsal points, range: 2.0 - 26.5 mm), 17.9 ± 3.9 mm (from hotspots to cranial points, range 7.2 - 27.5 mm), and 14.8 ± 3.6 mm (from hotspots to caudal points, 6.5 - 24.2 mm) were measured.
Conclusions: This is the first study that investigated the spatial resolution of rTMS language mapping by distinguishing between functionally relevant (=language-positive) and non-relevant (=language-negative) cortical spots via systematic distance measurement. Moreover, the spatial resolution of rTMS should principally allow for the identification of a particular gyrus, and it is in good accordance with the spatial resolution of direct cortical stimulation (DCS), which is regarded as the gold standard method in terms of cortical mapping.