INTRODUCTION:

Tongue protrusion dystonia can cause difficulty with speech, mastication, breathing, and swallowing. Deep brain stimulation (DBS) of the globus pallidus internus (GPi) is a widespread therapeutic alternative for treating medically refractory dystonia. To our knowledge, detailed reports regarding DBS for tongue protrusion dystonia are rare. In this report, we describe two patients with "sticking out" tongue protrusion who had undergone bilateral GPi DBS.

METHODS:

Operations were performed with surface electromyographic (EMG) monitoring, microelectrode recording, and macrostimulation to identify the point at which tongue kinetic cells respond most effectively. The most effective location for active contacts was identified according to burst EMG response in the posteroventral GPi.

RESULTS:

Two years after DBS, total Burke, Fahn, and Marsden Dystonia Rating Scale scores of two patients were improved from 12.5 to 1 (92.0%) and from 13 to 1 (92.3%), respectively. One 58-year-old woman who lost 7 kg weight from not eating well improved enough to eat solid food and became free from choking. Another 54-year-old woman who had dysarthria and mumbled could speak more fluently and would not have complained difficulty in reading any more.

CONCLUSION:

Stimulation on posteroventral GPi for patients with idiopathic "sticking-out" tongue movement changes EMG pattern in orofacial muscles. This fact supports a reason for modulation of unknown circuit connecting tongue-specific area in motor cortex, and basal ganglia.

OBJECTIVE:

The clinical entity of thoracic radiculopathy following spinal cord stimulator (SCS) placement has not been previously described.

MATERIALS AND METHODS:

A retrospective review of prospectively acquired data on 172 patients, having undergone thoracic SCS placement at our institution, was performed. In addition, four patients were implanted at outside institutions, and were referred for revision. We examine our early experience with placement of thoracic SCS in surgically treated patients with chronic pain and 15 associated specific postoperative radicular pain complications along respective thoracic dermatomes. We postulate that preexisting thoracic spinal pathology affords less compliance in the placement of larger paddles, and subsequent radicular pain in a band-like abdominal fashion.

RESULTS:

A syndrome of thoracic radiculopathy, presenting as intractable lower thoracic or abdominal wall pain occurring in the immediate postoperative period, was identified in 15 patients. These patients subsequently underwent revision surgery, with either a more extensive laminectomy to further decompress the dorsal nerve roots or lead removal, both of which resulted in near immediate relief of symptoms.

CONCLUSIONS:

Thoracic radiculopathy may occur following SCS paddle lead placement. This clinical syndrome is characterized by its immediate postoperative development, band-like thoracic or abdominal pain pattern, severe pain that both overwhelms the incisional pain and is refractory to medications, and absence of motor deficit. The lateral placement of paddle leads increases the risk of radicular symptoms. Preoperative thoracic spine magnetic resonance imaging may be helpful in identifying patients who may be susceptible to this syndrome.

OBJECTIVES:

This multicenter prospective trial was conducted to evaluate the clinical performance of a new neurostimulation system designed to treat chronic pain through the electrical neuromodulation of the dorsal root ganglia (DRG) neurophysiologically associated with painful regions of the limbs and/or trunk.

MATERIALS AND METHODS:

Thirty-two subjects were implanted with a novel neuromodulation device. Pain ratings during stimulation were followed up to six months and compared with baseline ratings. Subjects also completed two separate reversal periods in which stimulation was briefly stopped in order to establish the effects of the intervention.

RESULTS:

At all assessments, more than half of subjects reported pain relief of 50% or better. At six months postimplant, average overall pain ratings were 58% lower than baseline (p < 0.001), and the proportions of subjects experiencing 50% or more reduction in pain specific to back, leg, and foot regions were 57%, 70%, and 89%, respectively. When stimulation was discontinued for a short time, pain returned to baseline levels. Discrete coverage of hard-to-treat areas was obtained across a variety of anatomical pain distributions. Paresthesia intensity remained stable over time and there was no significant difference in the paresthesia intensity perceived during different body postures/positions (standing up vs. lying down).

CONCLUSIONS:

Results of this clinical trial demonstrate that neurostimulation of the DRG is a viable neuromodulatory technique for the treatment of chronic pain. Additionally, the capture of discrete painful areas such as the feet combined with stable paresthesia intensities across body positions suggest that this stimulation modality may allow more selective targeting of painful areas and reduce unwanted side-effects observed in traditional spinal cord stimulation (SCS).

OBJECTIVE:

The objective of this study was to determine magnetic resonance imaging (MRI)-related heating for a low-intensity focused ultrasound pulsation (LIFUP) device used during MRI performed at 3 T/128 MHz.

MATERIALS AND METHODS:

A special phantom was constructed to mimic the thermal properties of the human brain, and a piece of human temporal bone (skull) was embedded on top. Four fluoroptic thermometry probes, placed above and below the skull, were used to measure temperature changes during MRI (3 T/128 MHz; scanner-reported head average specific absorption rate 1.1-2 W/kg) with and without concurrent LIFUP sonication. LIFUP sonication was applied using a focused ultrasound device (BXPulsar 1001, Brainsonix, Inc., Los Angeles, CA, USA) at a derated spatial-peak temporal-average intensity of 3870 mW/cm(2) .

RESULTS:

MRI performed at relatively high specific absorption rate (SAR) caused a slight elevation in temperature (≤0.6°C). Concurrent use of MRI at a medium-strength SAR and LIFUP sonication resulted in maximum temperature rise of 3.1°C after 8 min of continuous use.

CONCLUSIONS:

Under the specific conditions utilized for this investigation, LIFUP sonication does not appear to present significant heating risks when used concurrently with MRI. This information has important implications for the use of the LIFUP sonication in human subjects undergoing MRI at 3 T/128 MHz.

INTRODUCTION:

Spinal cord stimulators (SCS) function by transmission of electrical impulses to electrode contacts placed within the epidural space depending on the painful area to be treated. Because of the electrical nature of the SCS, there has been concern about the interaction between these devices and devices that monitor or augment the cardiac system. Implantable loop recorders help to identify the causes of syncope or palpitation by continuously evaluating and recording portions of an electrocardiograph in patients being evaluated for cardiac conduction arrhythmias. The purpose of the study is to simulate the possible effects of spinal cord stimulation on a Confirm cardiac monitor (St. Jude Medical, St. Paul, MN, USA).

METHODS:

Twenty patients without preexisting cardiac disease, who were successfully being treated with SCS, were enrolled. Confirm loop recorders (St. Jude Medical) were placed on their chest wall in a noninvasive manner, with all programmed at identical settings. Multiple stimulation settings were adjusted on the stimulators and the recordings from the Confirm loop recorder were analyzed for evidence of interference.

RESULTS:

Fifteen of the patients had no electrical noise detected at any of the tested combinations of stimulation. Five patients had some electrical "noise" detected by the loop recorder, but it did not inhibit the cardiologist evaluating the recording from analyzing the electrocardiograph for diagnostic purposes. At no point with any of the patients at any tested setting was there an appearance of a life-threatening arrhythmia.

CONCLUSION:

Our study demonstrates that spinal cord stimulation is unlikely to interfere with the data collected by the Confirm loop recorder, and the presence of an SCS should not interfere with the ability to use a loop recorder for diagnostic purposes.

OBJECTIVES:

Spinal cord stimulation (SCS) is a well-established modality for the treatment of chronic pain, and can utilize percutaneous or paddle leads. While percutaneous leads are less invasive, they have been shown to have higher lead migration rates. In this study, we compared the long-term outcomes and health-care costs associated with paddle and percutaneous lead implantation.

MATERIALS AND METHODS:

We utilized the MarketScan data base to examine patients who underwent percutaneous or paddle lead SCS system implantation from 2000 to 2009. Outcomes including complications, reoperation rates, and health-care costs were evaluated in propensity score matched cohorts using univariate and multivariate analyses.

RESULTS:

The study cohort was comprised of 13,774 patients. At 90 days following the initial procedure, patients in the SCS paddle group were more likely to develop a postoperative complication than patients receiving percutaneous systems (3.4% vs. 2.2%, p = 0.0005). Two-year (6.3% vs. 3.5%, p = 0.0056) and long-term (five+ years) (22.9% vs. 8.5%, p < 0.0008) reoperation rates were significantly higher in those with percutaneous lead systems. However, long-term health-care costs were similar for those receiving paddle and percutaneous leads ($169,768 vs. $186,139, p = 0.30).

CONCLUSIONS:

While the implantation of paddle leads is associated with slightly higher initial postoperative complications, these leads are associated with significantly lower long-term reoperation rates. Nonetheless, long-term health-care costs are similar between paddle and percutaneous leads. Additional improvements in SCS technologies that address the shortcomings of current systems are needed to reduce the risk of reoperation due to hardware failure. Further study is required to evaluate the efficacy of newer percutaneous and paddle SCS systems and examine their comparative outcomes.