Radiofrequency Lesioning Through Deep Brain Stimulation Electrodes in Patients with Generalized Dystonia

BACKGROUND

Deep brain stimulation (DBS) is an established treatment for generalized dystonia. However, the DBS device is sometimes removed owing to hardware complications. We present 4 cases of generalized dystonia treated with radiofrequency lesioning through DBS electrodes.

CASE DESCRIPTION

Four patients, 3 men and 1 woman (age range, 34-44 years), underwent DBS for generalized dystonia and subsequently developed complications, such as infection, necessitating removal of the devices. As stopping the stimulation caused recurrence of uncontrollable symptoms, radiofrequency lesioning was performed through the DBS electrodes under local anesthesia, and the DBS systems were removed under local or generalized anesthesia thereafter. The procedures performed were as follows: 2 patients had bilateral pallidotomy, 1 patient had unilateral pallidotomy, and 1 patient had pallidotomy and ipsilateral thalamotomy. As a result, in 4 patients, the dystonic symptoms did not worsen even after removal of the DBS systems during a follow-up period of 1-12 years. However, 1 patient had a small hemorrhage, and 2 patients showed recurrence of dystonia.

CONCLUSIONS

Radiofrequency lesioning with DBS electrodes is feasible in cases of generalized dystonia when the DBS leads have to be removed.

Effects of Pulsed Versus Conventional Versus Combined Radiofrequency for the Treatment of Trigeminal Neuralgia: A Prospective Study

BACKGROUND

During radiofrequency bursts of energy are applied to nervous tissue. The clinical advantages of this treatment remain unclear.

OBJECTIVES

We compared the effectiveness and pain relief for idiopathic trigeminal neuralgia (TN) after continuous radiofrequency (CRF), pulsed radiofrequency (PRF), and combined continuous and pulsed radiofrequency (CCPRF) treatment of the Gasserian ganglion (GG).

STUDY DESIGN

We conducted a randomized prospective study. Forty-three patients were included. Eleven patients were treated with PRF at 42°C for 10 minutes (PRF group), 12 patients received CRF for 270 seconds at 75 °C (CRF group), and 20 patients received PRF for 10 minutes at 42°C followed by CRF for at 60°C for 270 seconds (CCPRF group).

SETTING

Assuit University Hospital, Pain and Neurology outpatient clinics.

METHODS

Patients were assessed for pain, satisfaction, and consumption of analgesics at baseline and 7 days, one month, 6 months, 12 months, and 24 months after the procedure. The incidence of complications, anesthesia dolorosa, weakness of muscles of mastication, numbness, and technical complications, was evaluated after the procedure.

RESULTS

Excellent pain relief was achieved after 6, 12, and 24 months, respectively in 95%, 85%, and 70% of patients with CCPRF; 75%, 75%, and reduced to 50% among patients with CRF; and 82%, reduced to 9.1%, and 0% of patients with PRF. No complications were recorded in 75% of patients in the CCPRF and PRF groups. There was one case of anesthesia dolorosa, 4 cases of masseter muscle weakness, and 5 cases of severe numbness recorded in the CRF group.

LIMITATION

There was a small number of patients in each group.

CONCLUSION

The best results were observed in the CCPRF group, followed by the CRF group, and then the PRF group.Key words: Pulsed, continuous, radiofrequency, trigeminal neuralgia, Gasserian ganglion.

Radio frequency-mediated local thermotherapy for destruction of pancreatic tumors using Ni-Au core-shell nanowires

We present a novel method of radio frequency (RF)-mediated thermotherapy in tumors by remotely heating nickel (Ni)-gold (Au) core-shell nanowires (CSNWs). Ectopic pancreatic tumors were developed in nude mice to evaluate the thermotherapeutic effects on tumor progression. Tumor ablation was produced by RF-mediated thermotherapy via activation of the paramagnetic properties of the Ni-Au CSNWs. Histopathology demonstrated that heat generated by RF irradiation caused significant cellular death with pyknotic nuclei and nuclear fragmentation dispersed throughout the tumors. These preliminary results suggest that thermotherapy ablation induced via RF activation of nanowires provides a potential alternative therapy for cancer treatment.

Clinical Efficacy and Safety of a Monopolar Radiofrequency Device With Comfort Pulse Technology for the Treatment of Facial and Neck Laxity in Men

The objective of this study was to demonstrate the efficacy and safety of a monopolar radiofrequency treatment for facial and neck laxity in men. Twelve men received one treatment of the face and upper portion of the neck using an RF system with comfort pulsed technology. Standardized photographs were taken at baseline and at 1, 3, and 6 months of follow-up. Study investigators evaluated facial and neck laxity at baseline and all follow-up visits using the Fasil Laxity Scale. Patents and investigators assessed skin texture and overall appearance using the Quartile Improvement Scale. Average improvement in treated areas was statistically significant at 1-month (P<.01), 3-month (P=.02), and 6-month (P=.05) follow-up visits compared with baseline. Investigators rated greatest improvement in skin texture and overall appearance (mild to moderate) at the 3-month follow-up. Patient assessments demonstrated moderate improvement in skin laxity, skin texture, and overall appearance maintained out to 6 months after treatment. A total of 64% of patients were satisfied to very satisfied with treatment at the 6-month follow-up. One RF treatment of the face and neck yielded 20% reduction in facial laxity 1 month after treatment, with maintained improvement out to 6 months (15% reduction).

Fractional Microneedling Radiofrequency Treatment for Acne-related Post-inflammatory Erythema

Post-inflammatory erythema is a common result of acne inflammation and is cosmetically unacceptable without effective treatment. Fractional microneedling radiofrequency (FMR) has potential for treatment of post-inflammatory erythema. The aim of this study was to evaluate the efficacy and safety of this treatment. A retrospective chart review was undertaken of 25 patients treated with 2 sessions of radiofrequency at 4-week intervals and 27 patients treated with oral antibiotics and/or topical agents. Efficacy was assessed through an investigator's global assessment of photographs, and the analysis of erythema with image analysis software and photometric devices. Histological changes resulting from the treatment were evaluated by skin biopsy. FMR treatment resulted in significant improvements in erythema with no severe adverse effects. Histological study revealed a reduction in vascular markers and inflammation. FMR is a safe and effective treatment for post-inflammatory erythema, with potential anti-inflammatory and anti-angiogenetic properties.

Effects of low amplitude pulsed radiofrequency stimulation with different waveform in rats for neuropathic pain

Pulsed-radiofrequency (PRF) electrical stimulation has been widely used for chronic pain treatment. It has been demonstrated with advantages of low temperature over traditional continuous radiofrequency (CRF) lesions with higher amplitude and mono polar electrode to treat pain in clinics (frequency 500 KHz, Pulse duration 20 msec, Amplitude 45 V, Treatment 2 min). We compare the effects of different pulse waveforms and PRF parameters (Pulse duration 25 ms, Treatment duration 5 min, low amplitude of 2.5/1.25 V) with a miniature bi-polar electrode on Dorsal root ganglion (DRG). The pain relief effect due to PRF is evaluated by using Von Frey method for the pain threshold index based on behavior response to mechanical stimulus of various strengths. Experimental results of Von Frey Score show that the sinusoidal group has higher responses than the square wave one. Both fast and secondary expressed proteins of c-fos and pp38 are measured from spinal cord tissue sectioning slides to characterize the pain associated inflammatory responses and their responses due to PRF stimulation.

Two-treatment protocol for skin laxity using 90-Watt dynamic monopolar radiofrequency device with real-time impedance intelligence monitoring

Multiple devices are currently on the market that employ radiofrequency to non-invasively treat skin laxity and wrinkle reduction. The study device was a unique monopolar radiofrequency device FDA cleared for the treatment of wrinkles and rhytids. The delivery system allows constant monitoring of the real-time local skin impedance changes, which allows radiofrequency energy to be more uniformly dosed over an entire treatment area.

OBJECTIVE

The objective was to validate effectiveness of a modified treatment protocol for a unique monopolar radiofrequency device, which has been engineered with greater power and self-monitoring circuitry.

METHODS

Twenty-four female subjects received bilateral monopolar radiofrequency treatments to the mid and lower face from the sub malar region to the submentum. Subjects completed 1 and 3 month follow ups with digital imaging. Skin biopsies (on 4 subjects) and ultrasound measurements (on 12 subjects) were completed.

RESULTS

Assessments demonstrated a reduction in skin laxity of 35%, a reduction in fine lines/wrinkles of 42%, and a reduction in the appearance of global photodamage of 33%. Expert photograding demonstrated 92% of subjects showing at least a mild improvement in skin laxity at three months post treatment. 50 MHz ultrasound measurements in 12 subjects showed an increase of 19% in skin density. Histology showed a marked increase in dermal collagen and elastin fibers in two subjects who demonstrated a clinically noticeable reduction in skin laxity and minimal changes in two subjects who demonstrated minimal clinical improvements. There were no significant adverse events reported.

CONCLUSION

This modified radiofrequency device and treatment protocol was well tolerated and produced improvements in the appearance of skin laxity and overall anti-aging effects in the majority of subjects. Objective measurements including ultrasound and histology help explain the clinical outcome.

[Micro-plasma radio frequency treatment for facial post-burn hyperpigmentation]

OBJECTIVE

To observe the clinical effect of micro-plasma radio frequency treatment of facial post-burn hyperpigmentation.

METHODS

From June 2012 to August 2013, a total of 25 cases with facial post-burn hyperpigmentation were treated with micro-plasma treatment for 3-5 times. The roller tip was used with setting of 60-90 watts and 3-4 passes were performed in different directions. Treatments were repeated at an interval of 8 weeks.

RESULTS

All patients tolerated the pain. After treatment, the facial hyperpigmentation improved. Complete recovery was achieved in 4 cases; significant improvement in 11 cases; moderate in 7 cases and no effect in 3 cases. No hyperpigmentation, depigmentation and scar formation was observed.

CONCLUSION

Micro-plasma radio frequency treatment is an ideal treatment for post-burn hyperpigmentation with lower side effect.

[Comparative evaluation of efficacy of electropulse and laser lithotriptors in vitro]

The article presents a comparative study of the nanosecond electropulse and holmium laser lithotriptors in vitro. Two types of samples simulating the "hard" and "soft" urinary stones were used; for their preparation stomatological ultrastrength plaster BegoStone was used. For the tests, four sizes of samples of stones in the cuboid shape were made. The sizes of the probes and stones, to some extent, simulated real clinical situation. In the experiments for Ho:YAG laser lithotriptor (LL), three sizes of probes were used: 230, 365 and 600 microns; for electropulse lithotriptor (EPL) - 2.7, 3.6, 4.5, and 6 Fr probes. A comparison of the effectiveness of lithotriptors in the experiments was performed for pairs of probes, which corresponded to a specific size of the stones. Comparative studies were performed in water at room temperature. "Stones" with specified size for each type of probe of lithotriptors were placed on stainless steel mesh with a mesh size 2 x 2 mm, immersed in water. Distal part of the probe (tip) was placed at an angle of 900 to the horizontal surface of the "stone" and brought into contact with the sample. The experiment was stopped when the surface of the mesh was free of particles of "stone" destroyed. Each experiment with the type and size of the "stone" and the probe was repeated at least 5 times. The results showed that nanosecond EPL requires much lower energy and time costs than the LL, ie, its physical parameters are more effective for the destruction of all types of samples stones. For the destruction of the "soft" stones, EPL always required much less energy than for the he destruction of "hard" stones. At the same time, working with LL often required same energy, and sometimes even more than for the destruction of "hard" stone. For the two methods of contact lithotripsy, different depending on the pulse energy and the properties of the "stones" in their destruction is confirmed experimentally.

[The comparative estimation of the efficacy of fluctuorization and ipidacrine fluctuophoresis included in the combined treatment of the patients with lesions in the inferior alveolar nerve]

The objective of the present study was the comparative estimation of the effectiveness of fluctuating currents and fluctuophoresis of a 0.5% ipidacrine solution as the components of the combined treatment of the patients with lesions in the inferior alveolar nerve. The efficacy of the treatment was evaluated from the dynamics of intensity of painful sensation, the extent of sensory disturbances, the results of electrical pulp test for the lower jaw teeth, threshold sensitivity of the lower lip skin, the degree of hydration of the periodontal tissues in the region innervated by the alveolar nerve, and the character of peripheral dynamics in the area of the mental foramen. The study has demonstrated that the introduction of fluctuophoresis of the anticholinesterase agent ipidacrine in the combined treatment of the patients presenting with the lesions in the inferior alveolar nerve increases the efficacy of therapy by 55.3% compared with the application of fluctuating currents (p < 0.05).

[The application of a pulsed low-frequency electrostatic field for the prevention of premature ageing]

This paper demonstrates the effectiveness of the application of a pulsed low-frequency electrostatic field (PLFESF) in order to prevent premature ageing. The study involved 50 subjects. PLFESF therapy was conducted using the DEEP OSCILLATION-200 apparatus with the applicator moved 9.5 cm along the massage lines in the dorsal collar region during 15 minutes. The therapeutic course included 10 sessions of massage at regular intervals every other day. The control subjects did not receive PLFESF therapy. The analysis of the results obtained revealed the influence of effective PLFESF therapy on various biomarkers of ageing which gives reason to recommend this technique for the application for the normalization of hemodynamic parameters, the correction of asthenic-neurotic disorders, the improvement of the patients' well-being and, as a result, the reduction of the biological age and the prevention of premature ageing.

A method for deriving the coagulation boundary of liver tissue using a relational model of viscoelasticity and temperature in radio frequency ablation

Recently radiofrequency (RF) ablation has become increasingly important in treating liver cancers. RF ablation is ordinarily conducted using elastographic imaging to monitor the ablation procedure and the temperature of the electrode needle is displayed on the RF generator. However, the coagulation boundary of liver tissue in RF ablation is unclear and unconfident. This can lead to both excessive and insufficient RF ablation thereby diminishing the advantages of the procedure. In the present study, we developed a method for determining the coagulation boundary of liver tissue in RF ablation. To investigate this boundary we used the mechanical characteristics of biochemical components as an indicator of coagulation to produce a relational model for viscoelasticity and temperature. This paper presents the data acquisition procedures for the viscoelasticity characteristics and the analytical method used for the coagulation model. We employed a rheometer to measure the viscoelastic characteristics of liver tissue. To determine the model functional relationship between viscoelasticity and temperature, we used a least-square method and the minimum root mean square error was calculated to optimize the model functional relations. The functional relation between temperature and viscoelasticity was linear and non-linear in different temperature regions. The boundary between linear and non-linear functional relation was 58.0°C.

[Decoupling of multi-channel RF coil and its application in the intraoperative MRI]

The coupling from different elements of the multi-channel coil leads to the splitting of the resonance frequency and deviation from the Lamor frequency. Decoupling between different elements is the key technology in the design of the radiofrequency (RF) coil. The electrical decoupling circuits should vary with different arrangements of the elements. A novel method of decoupling for the RF coil used in the intraoperative MR-guided focused ultrasound system is reported in the paper. The prototype RF coil was made according to the proposed decoupling method. The bench test of the prototype showed that the performance of the decoupling of the coil was excellent. The images in vivo were acquired with the designed prototype RF coil.