Feasibility study on transcutaneous auricular vagus nerve stimulation using millimeter waves.

Objective. Electrical stimulation of the auricular vagus nerve is a non-invasive neuromodulation technique that has been used for various conditions, including depression, epilepsy, headaches, and cerebral ischemia. However, unwanted non-vagal nerve stimulations can occur because of diffused stimulations. The objective of this study is to develop a region-specific non-invasive vagus nerve stimulation (VNS) technique using the millimeter wave (MMW) as a stimulus for the auricular branch of the vagus nerve (ABVN).Approach. A numerical simulation was conducted to ascertain whether the MMW could excite the ABVN in the human outer-ear with a millimeter-scale spatial resolution. Additionally, MMW-induced neuronal responses in seven mice were evaluated. Transcutaneous auricular VNS (ta-VNS) was applied to the cymba conchae innervated by the AVBN using a 60-GHz continuous wave (CW). As a control, the auricle's exterior margin was stimulated and referred to as transcutaneous auricular non-vagus nerve stimulation (ta-nonVNS). During stimulation, the local field potential (LFP) in the nucleus tractus solitarii (NTS), an afferent vagal projection site, was recorded simultaneously.Main results. The ta-VNS with a stimulus level of 13 dBm showed a significant increase in the LFP power in the NTS. The mean increases in power (n = 7) in the gamma high and gamma very high bands were 8.6 ± 2.0% and 18.2 ± 5.9%, respectively. However, the ta-nonVNS with a stimulus level of 13 dBm showed a significant decrease in the LFP power in the NTS. The mean decreases in power in the beta and gamma low bands were 11.0 ± 4.4% and 10.8 ± 2.8%, respectively. These findings suggested that MMW stimulation clearly induced a different response according to the presence of ABVN.Significance. Selective auricular VNS is feasible using the MMW. This study provides the basis for the development of a new clinical treatment option using the stimulation of the ta-VNS with a square millimeter spatial resolution.

Ultrasound-guided steroid injection for the treatment of de Quervain's disease: an anatomy-based approach.

OBJECTIVE: To suggest different ultrasound-guided steroid injection (USI) techniques based on anatomical variations of the first extensor compartment (FEC), and to evaluate the usefulness of it, in patients with de Quervain's disease. MATERIALS AND METHODS: Twenty-eight patients who underwent USI for de Quervain's disease were included. Anatomical variations were classified into complete sub-compartmentalization (n = 11), distal incomplete sub-compartmentalization (n = 5), and no sub-compartmentalization (n = 12) on ultrasound. Involved sub-compartments were recorded in patients with complete sub-compartmentalization. USIs were performed based on the anatomical variations: in both sub-compartments (n = 2) or only in the affected sub-compartment (n = 9) depending on the location of tenosynovitis involvement, in patients with complete sub-compartmentalization; in proximal FEC in patients with distal incomplete sub-compartmentalization (n = 5); in the common compartment in patients with no sub-compartmentalization (n = 12). Medical charts were retrospectively reviewed for evaluation of clinical outcome at follow-up visits. RESULTS: Twenty-three out of 28 patients were followed up with a mean period of 31.2 days after injection (6~87 days). Mean VAS was 7.96 before injection (range: 4 to 10), which was significantly reduced to 0.65 at rest and 1.57 during activity at follow-up visits (p < 0.05). Twenty-two out of 23 patients were satisfied with the results. The mean proportion of subjective pain reduction was 82.0% (median 95%). CONCLUSION: Ultrasound-guided steroid injections using different injection techniques based on the anatomical variations of the FEC have shown to be beneficial in the management of de Quervain's disease.

de Quervain disease: US identification of anatomic variations in the first extensor compartment with an emphasis on subcompartmentalization.

PURPOSE: To demonstrate the usefulness of ultrasonography (US) in the detection of anatomic variations in the first extensor compartment of the wrist in patients with de Quervain disease. MATERIALS AND METHODS: The institutional review board approved this study protocol and waived the informed consent requirement. Fifteen wrists in 13 women (age range, 41-62 years) in whom de Quervain disease was clinically diagnosed and who underwent surgery for intractable pain were included. A musculoskeletal radiologist performed US before surgery. The absence or presence and extent of subcompartmentalization within the first extensor compartment and the number of abductor pollicis longus (APL) and extensor pollicis brevis (EPB) tendon slips were evaluated and recorded. Preoperative US findings were compared with surgical records and photographs. RESULTS: Subcompartmentalization within the first extensor compartment was observed during surgery in 11 of the 15 wrists (73%), including four (27%) that had subcompartmentalization only in the distal portion of this compartment. US was used to identify all 11 wrists showing subcompartmentalization within this compartment (sensitivity, 100%; 95% confidence interval [CI]: 74%, 100%), as well as three of the four wrists with distal incomplete subcompartmentalization. There was one wrist with false-positive distal incomplete subcompartmentalization. US had a positive predictive value in the detection of subcompartmentalization of 73% (95% CI: 47%, 91%). The number of tendon slips in this compartment detected with US was identical to that identified at surgery with one exception. CONCLUSION: US can be used to depict various types of anatomic variations in the first extensor compartment in patients with de Quervain disease.

Chemical ablation of the gallbladder with acetic acid.

PURPOSE: Chemical ablation of the gallbladder may be a useful alternative to surgery for inoperable disease. The purpose of this study was to investigate the feasibility of chemical ablation of the gallbladder with acetic acid in a canine model. MATERIALS AND METHODS: Five beagle dogs underwent percutaneous transhepatic cholecystostomy. Percutaneous occlusion of the cystic duct was performed with use of n-butyl cyanoacrylate (NBCA) and coils. After confirmation of occlusion of the cystic duct, sclerotherapy of the gallbladder was performed with 4-7 mL of 50% acetic acid through the drainage catheter. Acetic acid was retained for 20 minutes with intermittent position change. The drainage catheter was removed immediately after sclerotherapy. The dogs were euthanized 8 weeks after the procedure. The gallbladders and adjacent organs were evaluated grossly as well as microscopically. RESULTS: All dogs survived without serious complications during the experimental period. Sclerotherapy was technically successful in all dogs. Gross specimens of the gallbladder showed shrinkage and fibrotic change without retention of any bile, mucus, or pus. Histologic examinations from the body and fundus of the gallbladder demonstrated complete ablation of the mucosa. However, the neck region of the gallbladder near the cystic duct, where NBCA and coils for cystic duct occlusion were located, had focal areas of remnant or regenerating mucosa. CONCLUSIONS: Chemical ablation of the gallbladder with 50% acetic acid was effective and safe. Complete ablation was achieved in the majority of gallbladder mucosa except for a small portion located in the gallbladder neck.

Calcifying aponeurotic fibroma with osseous involvement of the finger: a case report with radiologic and US findings.

Calcifying aponeurotic fibroma is a rare soft tissue tumor that occurs in the distal extremities of children and adolescents. We report ultrasound and X-ray findings of a calcifying aponeurotic fibroma in the finger of a 36-year-old woman, associated with distal phalangeal bone involvement.

The use of magnetic resonance imaging to predict the clinical outcome of non-surgical treatment for lumbar intervertebral disc herniation.

OBJECTIVE: We wanted to investigate the relationship between the magnetic resonance (MR) findings and the clinical outcome after treatment with non-surgical transforaminal epidural steroid injections (ESI) for lumbar herniated intervertebral disc (HIVD) patients. MATERIALS AND METHODS: Transforaminal ESI were performed in 91 patients (50 males and 41 females, age range: 13-78 yrs) because of lumbosacral HIVD from March 2001 to August 2002. Sixty eight patients whose MRIs and clinical follow-ups were available were included in this study. The medical charts were retrospectively reviewed and the patients were divided into two groups; the successful (responders, n = 41) and unsatisfactory (non-responders, n = 27) outcome groups. A successful outcome required a patient satisfaction score greater than two and a pain reduction score greater than 50%. The MR findings were retrospectively analyzed and compared between the two groups with regard to the type (protrusion, extrusion or sequestration), hydration (the T2 signal intensity), location (central, right/left central, subarticular, foraminal or extraforaminal), and size (volume) of the HIVD, the grade of nerve root compression (grade 1 abutment, 2 displacement and 3 entrapment), and an association with spinal stenosis. RESULTS: There was no significant difference between the responders and non-responders in terms of the type, hydration and size of the HIVD, or an association with spinal stenosis (p > 0.05). However, the location of the HIVD and the grade of nerve root compression were different between the two groups (p < 0.05). CONCLUSION: MRI could play an important role in predicting the clinical outcome of non-surgical transforaminal ESI treatment for patients with lumbar HIVD.