Background: A new intracerebral microinjection instrument (IMI) allowing multiple electrophysiologically guided microvolume injections from a single proximal injection path in rats has been adapted to clinical use by coupling the IMI to an FHC microTargeting Manual Drive, designed to be used with standard stereotactic frame-based systems and FHC frameless microTargeting Platforms. Methods: The function and safety of the device was tested by conducting bilateral electrophysiologically guided microinjections of fluorescent microspheres in the substantia nigra of 4 Göttingen minipigs. Results: The device was easy to handle and enabled accurate electrophysiologically guided targeting of the substantia nigra with minimal local tissue damage. Conclusion: The IMI is suitable for clinical use and may prove useful for various stereotactic procedures that require high levels of precision and/or three-dimensional distribution of therapeutics within the brain.

Background Refinement of the subthalamic nucleus (STN) coordinates using intraoperative microelectrode recordings (MER) is routinely performed during deep brain stimulation (DBS) surgeries in Parkinson disease (PD). The commonly used criteria for electrophysiological localization of the STN are qualitative. The goal of this study was to validate quantitative STN detection algorithm (QD) derived from the multi-unit activity in a prospective setting. Methods Ten PD patients underwent STN DBS surgery. The MUA was obtained by removing large spikes close to microelectrode using wavelet method and integrating the 500-2000 Hz band in the power spectral density. The qualitative intraoperative mapping of the STN using MER (IOM) versus QD was compared using Bland-Altman and Pearson’s correlation analysis. Results The clinical efficacy was confirmed in all subjects. The mean difference between IOM and QD of the dorsal/ventral border was 0.31±0.84/0.44±0.47 mm. Using Bland-Altman statistic, only 2/36 (5.6%) differences (one for the dorsal border and one for the ventral border) were out of ±2 sd line of measurement differences. Correlation between dorsal border/ventral borders positions obtained by IOM and QD was 0.79, p<0.0001/0.91, p<0.0001. Conclusion Both methods are in reasonable agreement and are strongly correlated. The QD gives objective coordinates of the STN borders at high precision and may be more accurate than IOM. Prospective blinded comparative studies where the DBS leads will be placed using either QD or IOM are warranted.

We present a 71-year-old male with oral melanoma and mantle cell hyperplasia who was erroneously diagnosed and treated as mantle cell lymphoma. The differential diagnosis of MCL versus mantle cell hyperplasia is a challenging task. Thorough immunohistochemical and cytogenetic analyses are warranted before treatment administration. The more common presentation of amelanotic malignant melanoma requires a high index of suspicion for masses identified in the mouth and requires biopsy for definitive diagnosis. A meticulous physical examination is advocated.