Diffuse reflectance spectroscopy measurements for tissue-type discrimination during deep brain stimulation.

Diffuse reflectance spectroscopy as a method for improving intracerebral guidance during functional neurosurgery has been investigated. An optical probe was developed for measurements during stereotactic and functional neurosurgery in man. The aim of the study was to investigate the spectral differences between white and grey matter and between white matter and functional targets.

A laser Doppler system for intracerebral measurements during stereotactic neurosurgery.

A laser Doppler system for intracerebral measurements during stereotactic and functional neurosurgery is presented. The system comprises a laser Doppler perfusion monitor, an optical probe adapted for the Leksell Stereotactic System and a personal computer with software for acquisition, data analysis and presentation. The software makes it possible to present both the perfusion and the total backscattered light intensity (TLI) in real-time.

Intracerebral microvascular measurements during deep brain stimulation implantation using laser Doppler perfusion monitoring.

The aim of the study was to investigate if laser Doppler perfusion monitoring (LDPM) can be used in order to differentiate between gray and white matter and to what extent microvascular perfusion can be recorded in the deep brain structures during stereotactic neurosurgery. An optical probe constructed to fit in the Leksell Stereotactic System was used for measurements along the trajectory and in the targets (globus pallidus internus, subthalamic nucleus, zona incerta, thalamus) during the implantation of deep brain stimulation leads (n = 22). The total backscattered light intensity (TLI) reflecting the grayness of the tissue, and the microvascular perfusion were captured at 128 sites.

Optical measurements during experimental stereotactic radiofrequency lesioning.

The aim of this study was to evaluate in vivo a laser Doppler measurement system in porcine brain tissue during thermal lesioning. A 2-mm monopolar radiofrequency lesioning electrode was equipped with optical fibers in order to monitor the lesioning procedure. Laser Doppler and backscattered light intensity signals were measured along the electrode trajectory and during bilateral lesioning in the central gray (70, 80 and 90 degrees C, n = 14).

Radio frequency electrode system for optical lesion size estimation in functional neurosurgery.

Radiofrequency (RF) lesioning in the human brain is one possible surgical therapy for severe pain as well as movement disorders. One obstacle for a safer lesioning procedure is the lack of size monitoring. The aim of this study was to investigate if changes in laser Doppler or intensity signals could be used as markers for size estimation during experimental RF lesioning.