Signals from intraventricular depth electrodes can control a brain-computer interface

A brain-computer interface (BCI) is a device that enables severely disabled people to communicate and interact with their environments using their brain waves. Most research investigating BCI in humans have used scalp-recorded electroencephalography (EEG). We have recently demonstrated that signals from intracranial electrocorticography (ECoG) and stereotactic depth electrodes (SDE) in the hippocampus can be used to control a BCI P300 Speller paradigm. We report a case in which stereotactic depth electrodes positioned in the ventricle were able to obtain viable signals for a BCI. Our results demonstrate that event-related potentials from intraventricular electrodes can be used to reliably control the P300 Speller BCI paradigm.     

A low cost color visual stimulator for fMRI

This low cost visual stimulator was developed for use in small animal imaging. The stimulator uses a single tri-color LED for each eye and can output red, green, or blue light or any combination of the three. When all three LED colors are illuminated at the same time achromatic light is the output. The stimulator is almost entirely implemented in software with only minimal electronics. The LEDs are controlled via the parallel port of a desktop computer. Flicker frequency, wavelength, intensity and waveform shape are under software control. The LEDs are coupled to fiber optic cables which run into the MRI scanner room leaving the LEDs and the power source in the control room. Calibration with a radiometer shows the light output to be very linear from zero to full intensity. The stimulator was used in fMRI visual stimulation studies performed on Sprague Dawley rats with an 11.7 Tesla magnet. As the stimulator is software driven, modifications to accommodate other protocols and extensions for new functionality can be readily incorporated. With this in mind, the visual stimulator circuit diagram and software including source code are available upon request.     

Transcranial imaging of functional cerebral hemodynamic changes in single blood vessels using in vivo photoacoustic microscopy

Optical imaging of changes in total hemoglobin concentration (HbT), cerebral blood volume (CBV), and hemoglobin oxygen saturation (SO(2)) provides a means to investigate brain hemodynamic regulation. However, high-resolution transcranial imaging remains challenging. In this study, we applied a novel functional photoacoustic microscopy technique to probe the responses of single cortical vessels to left forepaw electrical stimulation in mice with intact skulls. Functional changes in HbT, CBV, and SO(2) in the superior sagittal sinus and different-sized arterioles from the anterior cerebral artery system were bilaterally imaged with unambiguous 36 × 65-μm(2) spatial resolution. In addition, an early decrease of SO(2) in single blood vessels during activation (i.e., 'the initial dip') was observed. Our results indicate that the initial dip occurred specifically in small arterioles of activated regions but not in large veins. This technique complements other existing imaging approaches for the investigation of the hemodynamic responses in single cerebral blood vessels.     

An easy adjustable method of ectatic vertebrobasilar artery transposition for microvascular decompression

Background

Microvascular decompression (MVD) of trigeminal neuralgia (TN) or hemifacial spasm (HFS) caused by an elongated, tortuous or enlarged vertebral or basilar artery has a higher rate of incomplete cure.

Objective

We used an easily applied and adjustable method of vertebrobasilar artery transposition and fixation to improve the immediate surgical outcome of MVD of TN or HFS due to compression by an ectatic vertebrobasilar artery system.

Methods

Vertebral or basilar artery transposition was performed using the vascular sling with a strip of unabsorbable dural tape. The vertebrobasilar artery-sling complex was then fixed to the dura over the petrous bone by aneurysm clip through the dural bridge. The direction and angle of traction on the vertebrobasilar artery was adjustable using different lengths of clip or the horizontal level of the dural bridge.

Results

The sling and clip fixation method has been applied in 7 cases of MVD associated with vertebral or basilar artery compression. All 3 patients with TN and one with HFS had total remission of symptoms right after the procedure; one patient was completely free of spasm within 1 week after MVD and one had achieved 80% improvement of spasm in his last clinical visit 3 months after MVD. There was no major surgical complication in these 7 patients. Surprisingly, refractory hypertension was unexpectedly cured in one patient with TN following the procedure.

Conclusion

The vertebrobasilar artery transposition and fixation method used in the present study provided surgeons an easy and adjustable way to perform MVD safely and effectively.     

Hemophagocytic lymphohistiocytosis with isolated central nervous system reactivation and optic nerve involvement

Hemophagocytic lymphohistiocytosis is a rare childhood disorder characterized by uncontrolled proliferation of benign lymphocytes and histiocytes in multiple organs. Neurological presentations of central nervous system involvement are highly variable. The authors present a case of familial hemophagocytic lymphohistiocytosis in an 8-month-old girl with isolated central nervous system reactivation and optic nerve involvement. She presented with fever and hepatosplenomegaly at 2 months of age. Genetic studies confirmed familial hemophagocytic lymphohistiocytosis. There were no clinical features of central nervous system involvement at presentation. While on maintenance chemotherapy awaiting bone marrow transplant, she presented with new-onset seizures. Magnetic resonance imaging of the brain revealed extensive areas of abnormal signal and a thickened and enhancing left optic nerve. Ocular manifestations of hemophagocytic lymphohistiocytosis have rarely been described. To the authors' knowledge, this is the first case report of magnetic resonance imaging findings of optic nerve involvement in a child with hemophagocytic lymphohistiocytosis.     

Assisting people with disabilities to actively improve their collaborative physical activities with Nintendo Wii Balance Boards by controlling environmental stimulation

The latest researches have adopted software technology to modify the Nintendo Wii Balance Board functionality and used it to enable two people with developmental disabilities to actively perform physical activities. This study extended the latest research of the Wii Balance Board application to assess whether four people (two groups) with developmental disabilities would be able to actively improve their physical activities collaboration - walking to the designated location following simple instructions, by controlling their favorite environmental stimulation through using three Nintendo Wii Balance Boards. We employed an A-B-A-B design, with A represented the baseline and B represented intervention phases. Data showed that both groups of participants significantly increased their collaborative target response (collaboratively performing designated physical activities) by activating the control system to produce their preferred environmental stimulation during the intervention phases. Practical and developmental implications of the findings are discussed.     

Singing in groups for Parkinson's disease (SING-PD): a pilot study of group singing therapy for PD-related voice/speech disorders

Parkinson's disease related speech and voice impairment have significant impact on quality of life measures. LSVT^®LOUD voice and speech therapy (Lee Silverman Voice Therapy) has demonstrated scientific efficacy and clinical effectiveness, but musically based voice and speech therapy has been underexplored as a potentially useful method of rehabilitation. We undertook a pilot, open-label study of a group-based singing intervention, consisting of twelve 90-min weekly sessions led by a voice and speech therapist/singing instructor. The primary outcome measure of vocal loudness as measured by sound pressure level (SPL) at 50 cm during connected speech was not significantly different one week after the intervention or at 13 weeks after the intervention. A number of secondary measures reflecting pitch range, phonation time and maximum loudness also were unchanged. Voice related quality of life (VRQOL) and voice handicap index (VHI) also were unchanged. This study suggests that a group singing therapy intervention at this intensity and frequency does not result in significant improvement in objective and subject-rated measures of voice and speech impairment.