Shayne Morris

Deep brain stimulation of the subthalamic nucleus improves temperature sensation in patients with Parkinson's disease.

&NA; Patients with Parkinson’s disease (PD) reportedly show deficits in sensory processing in addition to motor symptoms. However, little is known about the effects of bilateral deep brain stimulation of the subthalamic nucleus (STN‐DBS) on temperature sensation as measured by quantitative sensory testing (QST). This study was designed to quantitatively evaluate the effects of STN‐DBS on temperature sensation and pain in PD patients. We conducted a QST study comparing the effects of STN‐DBS on cold sense thresholds (CSTs) and warm sense thresholds (WSTs) as well as on cold‐induced and heat‐induced pain thresholds (CPT and HPT) in 17 PD patients and 14 healthy control subjects. The CSTs and WSTs of patients were significantly smaller during the DBS‐on mode when compared with the DBS‐off mode (P < .001), whereas the CSTs and WSTs of patients in the DBS‐off mode were significantly greater than those of healthy control subjects (P < .02). The CPTs and HPTs in PD patients were significantly larger on the more affected side than on the less affected side (P < .02). Because elevations in thermal sense and pain thresholds of QST are reportedly almost compatible with decreases in sensation, our findings confirm that temperature sensations may be disturbed in PD patients when compared with healthy persons and that STN‐DBS can be used to improve temperature sensation in these patients. The mechanisms underlying our findings are not well understood, but improvement in temperature sensation appears to be a sign of modulation of disease‐related brain network abnormalities. Quantitative evaluation on the effect of deep brain stimulation of the subthalamic nucleus on temperature sensation and pain suggested that it could improve impaired temperature sensation in patients with Parkinson’s disease.

Differential Efficacy of Electric Motor Cortex Stimulation and Lesioning of the Dorsal Root Entry Zone for Continuous vs Paroxysmal Pain After Brachial Plexus Avulsion

BACKGROUND:Pain after traumatic brachial plexus avulsion (BPA) has 2 distinct patterns: continuous burning pain and paroxysmal shooting pain. Lesioning of the dorsal root entry zone (DREZotomy) is more effective for paroxysmal than continuous pain. It is unknown, however, whether electric motor cortex stimulation (EMCS) has a differential effect on continuous vs paroxysmal BPA pain. OBJECTIVE:To analyze the differential effect of EMCS and DREZotomy on continuous vs paroxysmal BPA pain in a series of 15 patients. METHODS:Fifteen patients with intractable BPA pain underwent DREZotomy alone (n = 7), EMCS alone (n = 4), or both procedures (n = 4). Pain intensity was evaluated with the Visual Analog Scale, and separate ratings were recorded for paroxysmal and continuous pain. Pain relief was categorized as excellent (> 75% pain relief), good (50%-75%), or poor (< 50%). Favorable outcome was defined as good or better pain relief. RESULTS:Eight patients had EMCS; 7 were followed up for an average of 47 months. Of those 7 patients, 3 (42%) with continuous pain had favorable outcomes compared with no patients with paroxysmal pain. Eleven patients had DREZotomy; 10 were followed up for an average of 31 months. Of those 10 patients, 7 (70%) with paroxysmal pain had favorable outcomes compared with 2 (20%) with continuous pain. CONCLUSION:EMCS was ineffective for paroxysmal pain but moderately effective for continuous pain. DREZotomy was highly effective for paroxysmal pain but moderately effective for continuous pain. It may be prudent to use EMCS for residual continuous pain after DREZotomy.

Validity, Reliability, and Assessment Sensitivity of the Japanese Version of the Short-Form McGill Pain Questionnaire 2 in Japanese Patients with Neuropathic and Non-Neuropathic Pain

OBJECTIVE The objective of this study was to define the validity, reliability, and assessment sensitivity of the Japanese version of the Short-Form McGill Pain Questionnaire 2 (SF-MPQ-2-J). DESIGN This is a cross-sectional study. PATIENTS AND METHODS The original SF-MPQ-2 was translated into Japanese to create the SF-MPQ-2-J, and the cross-cultural equivalence of assessment tool for Japanese patients was validated. The reliability of the SF-MPQ-2-J was assessed using internal consistency, reliability coefficients (Cronbachs α), and reproducibility coefficients (intraclass correlation coefficient) obtained using 234 patients with chronic pain. SF-MPQ-2-J validity was assessed based on associations identified between total and subscale scores compared with other assessment methods. A confirmatory factor analysis (CFA) was also performed to test the theoretical structure of the SF-MPQ-2-J. RESULTS The internal consistencies calculated included continuous pain, α=0.893; intermittent pain, α=0.875; predominantly neuropathic pain, α=0.917; affective descriptors, α=0.857; and total score, α=0.907. The reproducibility coefficients calculated included continuous pain, ρ=0.81; intermittent pain, ρ=0.78; predominantly neuropathic pain, ρ=0.85; affective descriptors, ρ=0.75; and total score, ρ=0.83. The CFA showed that the model fit of the readily interpretable subscales was acceptable, and the goodness of fit index value was 0.917. In addition, the mean predominantly neuropathic pain subscale score was found to be significantly higher for patients with neuropathic pain vs non-neuropathic pain. CONCLUSION These findings suggest that the reliability and validity of the SF-MPQ-2-J are excellent, and the SF-MPQ-2-J represents a cross-cultural equivalent to SF-MPQ-2. Consequently, the latter is suitable for research and clinical use, and for discriminating neuropathic pain from non-neuropathic pain.

Patient-Specific Cortical Electrodes for Sulcal and Gyral Implantation

Purpose: Noninvasive localization of certain brain functions may be mapped on a millimetre level. However, the interelectrode spacing of common clinical brain surface electrodes still remains around 10 mm. Here, we present details on development of electrodes for attaining higher quality electrocorticographic signals for use in functional brain mapping and brain-machine interface (BMI) technologies. Methods: We used platinum-plate-electrodes of 1-mm diameter to produce sheet electrodes after the creation of individualized molds using a 3-D printer and a press system that sandwiched the electrodes between personalized silicone sheets. Results: We created arrays to fit the surface curvature of the brain and inside the central sulcus, with interelectrode distances of 2.5 mm (a density of 16 times previous standard types). Rat experiments undertaken indicated no long term toxicity. We were also able to custom design, rapidly manufacture, safely implant, and confirm the efficacy of personalized electrodes, including the capability to attain meaningful high-gamma-band information in an amyotrophic lateral sclerosis patient. Conclusion: We developed cortical sheet electrodes with a high-spatial resolution, tailor-made to match an individuals brain. Significance: This sheet electrode may contribute to the higher performance of BMIs.

Daily Repetitive Transcranial Magnetic Stimulation for Poststroke Upper Limb Paresis in the Subacute Period

BACKGROUND We conducted a randomized, double-blind, sham-controlled study to assess the efficacy in motor recovery and safety of daily repetitive transcranial magnetic stimulation (rTMS) in subacute stroke patients. METHODS Forty-one patients were randomly assigned to a real or sham stimulation group. Each patient underwent regular rehabilitation accompanied by a series of 10 daily 5-Hz rTMS of the ipsilesional primary motor cortex (M1) or sham stimulation. The primary outcome was motor recovery evaluated by the Brunnstrom stages (BS). The secondary outcomes were improvement in the Fugl-Meyer Assessment (FMA), grip power, National Institutes of Health Stroke Scale (NIHSS), Functional Independence Measure (FIM), a quantitative measurement of finger tapping movement, and the incidence of adverse events. RESULTS Thirty-nine patients completed the study and were included in the analyses. The real rTMS group demonstrated additional improvement in the BS hand score at the last follow-up compared to the sham. The grip power, the NIHSS motor score, and the number of finger taps in the affected hand improved in the real stimulation group but not in the sham group. The BS upper limb scores, the FMA distal upper limb score, the NIHSS total score, and the FIM motor score showed improvement from baseline at the earlier time points after the real rTMS. There were no additional improvements in the other scores after the real rTMS compared to the sham. No serious adverse events were observed. CONCLUSIONS Our results suggest that dailyhigh-frequency rTMS of the ipsilesional M1 is tolerable and modestly facilitates motor recovery in the paralytic hand of subacute stroke patients.

Severely affected ALS patients have broad and high expectations for brain-machine interfaces

Abstract Brain-machine interfaces (BMIs) may provide new communication channels and motor function to individuals with severe neurodegenerative diseases, but little is known about their interests in such devices. We investigated the interests of severely affected ALS patients in BMIs, and examined factors that might influence these interests. We conducted an anonymous, mail-back questionnaire survey of severely disabled ALS patients diagnosed using the revised El Escorial criteria. Thirty-seven patients responded to the questionnaire. Twenty-nine (78.4%) had undergone tracheostomy positive pressure ventilation. More than 80% of the patients were interested in communication support. Thirty-three (89.2%) felt stressed during communication. Among those using assistive communication devices (17 patients), 15 (88.2%) were not satisfied with them. More than 50% of the patients expressed an interest in BMIs. Their expectations of BMIs ranged widely from emergency alarm to postural change. The frequent use of personal computers tended to be correlated with an interest in invasive BMIs (p = 0.07). In conclusion, this was the first questionnaire survey demonstrating that severely affected ALS patients have broad and high expectations for BMIs. Communication was the most desired support from BMIs for such patients. We need to meet their widely ranging expectations of BMIs.

Motor Restoration Based on the Brain–Machine Interface Using Brain Surface Electrodes: Real-Time Robot Control and a Fully Implantable Wireless System

The brain–machine interface (BMI) is a new approach to the man–machine interface, which enables us to control machines and to communicate with others without input devices, but directly using brain signals. We describe our integrative approach to develop a BMI system using brain surface electrodes for motor and communication control in severely disabled people. This includes effective brain signal recording, accurate neural decoding, robust robot control, a wireless fully implantable device, a non-invasive evaluation of surgical indications, etc. In addition, the inspection and addressing of neuroethical issues is indispensible when undertaking work in this field.

The optimal stimulation site for high-frequency repetitive transcranial magnetic stimulation in Parkinson’s disease: A double-blind crossover pilot study

Many reports have shown improvements in motor symptoms after repetitive transcranial magnetic stimulation (rTMS). However, the best stimulation area in the brain has not currently been determined. We assessed the effects of high-frequency rTMS (HF-rTMS) on the motor and mood disturbances in Parkinsons disease (PD) patients and attempted to determine whether the primary motor area (M1), the supplementary motor area (SMA), and the dorsolateral prefrontal cortex (DLPFC) were the best treatment targets. In this randomized, double-blind crossover design study, we investigated the efficacy of 3 consecutive days of HF-rTMS over the M1, SMA, and DLPFC and compared these HF-rTMS to sham stimulations. We used motor and non-motor scales to evaluate the parkinsonian symptoms. The changes in the Unified Parkinsons Disease Rating Scale part III (UPDRS-III) scores after the application of HF-rTMS over the M1 and SMA were significantly greater than those after the sham stimulation. However, after the application of HF-rTMS over the DLPFC, the UPDRS-III scores were similar to those after the sham stimulation. No significant improvements were demonstrated in the mood disturbances after the stimulations over any of the targets. In conclusion, the application of HF-rTMS over the M1 and SMA significantly improved the motor symptoms in the PD patients but did not alter the mood disturbances.

Which is the Most Appropriate Disconnection Surgery for Refractory Epilepsy in Childhood

Children with unilobar or multilobar pathology issuing in refractory epilepsy are potential candidates for surgical treatment. Extensive surgery results in good seizure control, but it also increases the risk of neurological deficits as well as motor and mental problems. We reviewed the cases of 19 children with refractory epilepsy treated surgically at Osaka University Hospital. Four of the 19 patients underwent temporal disconnection, 2 underwent occipital lobectomy, 4 underwent temporoparietooccipital disconnection, 6 underwent functional hemispherotomy, and 3 underwent corpus callosotomy. A good surgical outcome, i.e., Engel’s class I or II, was achieved in 12 (63%) of the 19 patients. Excellent surgical outcomes and satisfactory motor and mental development were achieved in 4 patients who underwent temporoparietooccipital disconnection. The outcomes of functional hemispherectomy were also satisfactory. The outcomes of temporal disconnection and corpus callosotomy were poor in comparison to outcomes of the other procedures. We believe that better surgical outcomes would have been achieved with temporoparietooccipital disconnection in some cases treated by temporal disconnection or occipital resection. Adequate extensive surgical procedures should be considered for refractory childhood epilepsy arising from unilobar or multilobar pathology.

A fully implantable wireless ECoG 128-channel recording device for human brain–machine interfaces: W-HERBS

Brain–machine interfaces (BMIs) are promising devices that can be used as neuroprostheses by severely disabled individuals. Brain surface electroencephalograms (electrocorticograms, ECoGs) can provide input signals that can then be decoded to enable communication with others and to control intelligent prostheses and home electronics. However, conventional systems use wired ECoG recordings. Therefore, the development of wireless systems for clinical ECoG BMIs is a major goal in the field. We developed a fully implantable ECoG signal recording device for human ECoG BMI, i.e., a wireless human ECoG-based real-time BMI system (W-HERBS). In this system, three-dimensional (3D) high-density subdural multiple electrodes are fitted to the brain surface and ECoG measurement units record 128-channel (ch) ECoG signals at a sampling rate of 1 kHz. The units transfer data to the data and power management unit implanted subcutaneously in the abdomen through a subcutaneous stretchable spiral cable. The data and power management unit then communicates with a workstation outside the body and wirelessly receives 400 mW of power from an external wireless transmitter. The workstation records and analyzes the received data in the frequency domain and controls external devices based on analyses. We investigated the performance of the proposed system. We were able to use W-HERBS to detect sine waves with a 4.8-μV amplitude and a 60–200-Hz bandwidth from the ECoG BMIs. W-HERBS is the first fully implantable ECoG-based BMI system with more than 100 ch. It is capable of recording 128-ch subdural ECoG signals with sufficient input-referred noise (3 μVrms) and with an acceptable time delay (250 ms). The system contributes to the clinical application of high-performance BMIs and to experimental brain research.