To evaluate the risk of phrenic nerve injury during ultrasound-guided stellate ganglion block (US-SGB) according to sonoanatomy of the phrenic nerve, and determine a safer posture for needle insertion by assessing its relationship with surrounding structure according to positional change.
Twenty-nine healthy volunteers were recruited and underwent ultrasound in two postures, i.e., supine position with the neck extension and head rotation, and lateral decubitus position. The transducer was placed at the anterior tubercle of the C6 level to identify phrenic nerve. The cross-sectional area (CSA), depth from skin, distance between phrenic nerve and anterior tubercle of C6 transverse process, and the angle formed by anterior tubercle, posterior tubercle and phrenic nerve were measured.
The phrenic nerve was clearly identified in the intermuscular fascia layer between the anterior scalene and sternocleidomastoid muscles. The distance between the phrenic nerve and anterior tubercle was 10.33±3.20 mm with the supine position and 9.20±3.31 mm with the lateral decubitus position, respectively. The mean CSA and skin depth of phrenic nerve were not statistically different between the two positions. The angle with the supine position was 48.37°±27.43°, and 58.89°±30.02° with the lateral decubitus position. The difference of angle between the two positions was statistically significant.
Ultrasound is a useful tool for assessing the phrenic nerve and its anatomical relation with other cervical structures. In addition, lateral decubitus position seems to be safer by providing wider angle for needle insertion than the supine position in US-SGB.
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To investigate whether an audible cracking sound during shoulder manipulation following distention arthrography is clinically significant in patients with adhesive capsulitis of the shoulder.
A total of 48 patients (31 women, 17 men) with primary adhesive capsulitis of the shoulder completed the study. All participants underwent C-arm-guided arthrographic distention of the glenohumeral joint with injections of a corticosteroid and normal saline. After distention, we performed flexion and abduction manipulation of the shoulder. The patients were grouped into sound and non-sound groups based on the presence or absence, respectively, of an audible cracking sound during manipulation. We assessed shoulder pain and disability based on a Numeric Rating Scale (NRS), the Shoulder Pain and Disability Index (SPADI), and passive range of motion (ROM) measurements (flexion, abduction, internal and external rotation) before the procedure and again at 3 weeks and at 6 weeks after the intervention.
The patients were divided into two groups: 21 were included in the sound group and 27 in the non-sound group. In both groups, the results of the NRS, SPADI, and ROM assessments showed statistically significant improvements at both 3 and 6 weeks after the procedure. However, there were no significant differences between the two groups except with respect to external rotation at 6 weeks, at which time the sound group showed a significant improvement in external rotation when compared with the non-sound group (p<0.05).
These findings showed that manipulation following distention arthrography was effective in decreasing pain and increasing shoulder range of motion. In addition, the presence of an audible cracking sound during manipulation, especially on external rotation, was associated with better shoulder range of motion.
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To verify the utility of the lateral femoral cutaneous nerve (LFCN) ultrasound-guided conduction technique compared to that of the conventional nerve conduction technique.
Fifty-eight legs of 29 healthy participants (18 males and 11 females; mean age, 42.7±14.9 years) were recruited. The conventional technique was performed bilaterally. The LFCN was localized by ultrasound. Cross-sectional area (CSA) of the LFCN and the distance between the anterior superior iliac spine (ASIS) and the LFCN was measured. The nerve conduction study was repeated with the corrected cathode location. Sensory nerve action potential (SNAP) amplitudes of the LFCN were recorded and compared between the ultrasound-guided and conventional techniques.
Mean body mass index of the participants was 23.7±3.5 kg/m2, CSA was 4.2±1.9 mm2, and the distance between the ASIS and LFCN was 5.6±1.7 mm. The mean amplitude values were 6.07±0.52 µV and 6.66±0.54 µV using the conventional and ultrasound-guided techniques, respectively. The SNAP amplitude of the LFCN using the ultrasound-guided technique was significantly larger than that recorded using the conventional technique.
Correcting the stimulation position using the ultrasound-guided technique helped obtain increased SNAP amplitude.
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Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominantly inherited disorder that affects peripheral nerves by repeated focal pressure. HNPP can be diagnosed by clinical findings, electrodiagnostic studies, histopathological features, and genetic analysis. Ultrasonography is increasingly used for the diagnosis of neuromuscular diseases; however, sonographic features of HNPP have not been clearly defined. We report the sonographic findings and comparative electrodiagnostic data in a 73-year-old woman with HNPP, confirmed by genetic analysis. The cross-sectional areas of peripheral nerves were enlarged at typical nerve entrapment sites, but enlargement at non-entrapment sites was uncommon. These sonographic features may be helpful for diagnosis of HNPP when electrodiagnostic studies are suspicious of HNPP and/or gene study is not compatible.
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