Joon Shik Yoon

ULTRASONOGRAPHIC SWELLING RATIO IN THE DIAGNOSIS OF ULNAR NEUROPATHY AT THE ELBOW

High‐resolution ultrasound can demonstrate focal nerve enlargement in entrapment neuropathies. We hypothesized that a ratio between the nerve cross‐sectional area at the site of maximal enlargement and at an unaffected site may improve diagnostic accuracy in ulnar neuropathy at the elbow (UNE), when compared to a single measurement at the site of maximal enlargement. Ultrasound was used to measure the cross‐sectional area of the ulnar nerve at three sites in 30 normal, healthy controls and 26 individuals with UNE. In individuals with UNE, the ratio was 2.9:1 when the site of maximal swelling was compared with a distal ulnar nerve site and 2.8:1 when compared with a proximal site. This represented a significant increase compared with the ratio of 1.1:1 for both comparisons in controls (P < 0.0001). This type of ratio may be particularly useful for assessing entrapment in those with polyneuropathy or obesity, both of which can cause diffuse nerve enlargement. Muscle Nerve, 2008

Median nerve changes following steroid injection for carpal tunnel syndrome.

Introduction: Neuromuscular ultrasound is a painless, radiation‐free, high‐resolution imaging modality for assessment of the peripheral nervous system. The purpose of this study was to use neuromuscular ultrasound to assess the changes that occur in the median nerve after steroid injection for carpal tunnel syndrome (CTS). Methods: Ultrasound and nerve conduction studies were performed at baseline and 1 week, 1 month, and 6 months after steroid injection in 19 individuals (29 wrists) with CTS. Results: Significant changes were noted in median nerve cross‐sectional area (P < 0.001), mobility (P = 0.001), and vascularity (P = 0.042) at the distal wrist crease after steroid injection, and the nerve cross‐sectional area correlated with symptom score and electrodiagnostic parameters. Changes in the ultrasonographic parameters were seen within 1 week of injection. Conclusions: These findings suggest neuromuscular ultrasound is potentially helpful for the assessment of individuals undergoing treatment for CTS, as typical changes can be expected after successful treatment injection. Muscle Nerve 44: 25–29, 2011

Reference values for nerve ultrasonography in the upper extremity

The aims of this study were to identify factors affecting the measurement of nerve cross‐sectional area (CSA) and to establish normal reference values for nerve ultrasonography of the upper extremity.

The feasibility of color Doppler ultrasonography for caudal epidural steroid injection.

&NA; Although it entails a radiation hazard risk, the use of fluoroscopy during caudal epidural steroid injection has increased to help place the medication more accurately and allowed physicians to maximize the procedures therapeutic success rate. To investigate the feasibility of using real‐time high resolution ultrasonography for guiding the epidural needle into the caudal epidural space and to confirm any vascular intake of medication, we performed color Doppler ultrasonography while medication was being injected into the caudal epidural space of 53 patients with low back pain and sciatica. We defined the injection as being successful if unidirectional flow (observed as one dominant color) of the solution was observed with color Doppler ultrasonography through the epidural space beneath the sacrococcygeal ligament, with no flows being observed in other directions (observed as multiple colors). The correct placement of the medication was then confirmed by fluoroscopy. In 52 of the 53 subjects, the medications were successfully injected into the caudal epidural space with ultrasonography assistance. In fluoroscopy, of these 52 patients, 50 revealed correct placement of the medicine into the epidural space. In conclusion, ultrasonography may be a reliable imaging modality for caudal epidural steroid injection, and its several advantages such as its convenience and the lack of a radiation hazard, make it preferable to fluoroscopy.

Ultrasonographic measurements in cubital tunnel syndrome

The cubital tunnel is the most common site of ulnar nerve entrapment. Previous ultrasound studies have demonstrated enlargement of the ulnar nerve in cubital tunnel syndrome but did not report on the cubital tunnel itself. Twenty‐two individuals with cubital tunnel syndrome were evaluated with nerve conduction studies and ultrasound. The ultrasound measurement that most strongly correlated with conduction velocity was the ratio of ulnar nerve to cubital tunnel cross‐sectional area with the elbow flexed. Measurement of this ratio may improve the diagnostic accuracy of ultrasound in cubital tunnel syndrome, although further investigation is needed. Muscle Nerve, 2007

Ulnar nerve and cubital tunnel ultrasound in ulnar neuropathy at the elbow.

OBJECTIVE To determine the accuracy of the ultrasonographic measurement of ulnar nerve to cubital tunnel area for diagnosis of ulnar neuropathy at the elbow. DESIGN Patients with confirmed ulnar neuropathy at the elbow and normative, healthy volunteers were evaluated with high-resolution ultrasound. The cross-sectional areas (CSAs) of the ulnar nerve and cubital tunnel were measured with the elbow extended and flexed, and results from the 2 groups were compared. SETTING Electromyography laboratory and radiology department of a tertiary care center. PARTICIPANTS Twenty-seven patients with ulnar neuropathy at the elbow and 20 controls. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURE The ratio of ulnar nerve to cubital tunnel CSA with the elbow flexed. RESULTS The ulnar nerve, with the elbow flexed, was larger in those with ulnar neuropathy at the elbow, and this group also had larger cubital tunnels than did controls. In those with ulnar neuropathy at the elbow, the ratio of the ulnar nerve to cubital tunnel was .31, and in the controls it was .32, which was not significantly different (P=.89). CONCLUSIONS The ratio of ulnar nerve to cubital tunnel did not differentiate those with ulnar neuropathy at the elbow from controls.

Ulnar Neuropathy With Normal Electrodiagnosis and Abnormal Nerve Ultrasound

Ulnar neuropathy at the elbow (UNE) is the second most common entrapment neuropathy. It is diagnosed with electrodiagnostic studies, but they can yield false-negative results. Ultrasound was used to examine 4 patients with UNE and negative electrodiagnostic findings, and it showed ulnar nerve enlargement near the elbow in all cases, with a mean cross-sectional area of 20.1 mm. This indicates that ultrasound may be a useful tool for assessing those with UNE symptoms and normal electrodiagnostic findings.

Carpal tunnel syndrome: Clinical, electrophysiological, and ultrasonographic ratio after surgery

Introduction: The aim of this study was to improve our understanding of the pathophysiology of carpal tunnel syndrome (CTS) and to highlight the ultrasonographic cross‐sectional area (CSA) ratio as a tool for assessing outcomes by investigating postoperative changes. Methods: Twenty‐four individuals with CTS were evaluated using the Boston questionnaire, nerve conduction studies, and ultrasound, preoperatively and at 3 weeks and 3 months postoperatively. Results: Improved symptom scores, decreased CSA, and decreased CSA ratio were observed in the first 3 weeks, but functional improvement was also observed after 3 weeks postoperatively. The ratios between the CSA at the sites of enlargement and unaffected areas correlated significantly with the Padua classification, although the coefficient was not superior to the coefficient of CSA at the maximal swelling site. Conclusions: Symptoms improved more rapidly than function after surgery. Measurement of the ultrasonographic CSA ratio may provide clinicians with a useful assessment tool after surgery. Muscle Nerve, 2012

Intracranial hypotension induced by cervical spine chiropractic manipulation

Study Design. Case report. Objectives. We report a case of intracranial hypotension ensuing after a spinal chiropractic manipulation leading to cerebrospinal fluid (CSF) isodense effusion in the upper cervical and thoracic spine. Summary of Background Data. The etiology of intracranial hypotension is not fully understood, but CSF leakage from spinal meningeal diverticula or dural tears may be involved. Methods. A 36-year-old woman presented with neck and both shoulder pain 4 days earlier. She undertook a spinal chiropractic manipulation. After this maneuver, she complained of a throbbing headache with nausea and vomitting. Her headache worsened, and lying down gave the only measure of limited relief. In CSF study, it showed dry tapping. Brain MRI showed pachymeningeal gadolinum enhancement. Thoracic spine MRI showed CSF leakage. After admission to the hospital, she was treated by hydration and pain control over several days. However, her headache did not improve. Results. She was treated by epidural blood patch. Afterwards, her headache was improved. This is the first case of spontaneous intracranial hypotension in which spinal chiropractic manipulation coincided with the development of symptoms and in which a CSF collection in the upper cervical and thoracic spine was demonstrated radiographically in Korea. Conclusions. From this case, we can understand the etiology of intracranial hypotension and consider the complication of chiropractic manipulation.

Measurement of cross-sectional area of cervical roots and brachial plexus trunks.

Introduction: The aim of this study was to determine normal reference values for cross‐sectional area (CSA) and the correlation between demographic factors and CSA in the cervical roots and brachial plexus trunks using ultrasonography. Methods: Ninety‐five age‐matched healthy individuals were studied. Ultrasonographic tests were performed via nerve tracing from the cervical root to the brachial plexus trunk. The CSA of each nerve was measured in the C5–8 ventral roots and brachial plexus (trunk level). Results: Normal values of each cervical root were: C5, 5.66 ± 1.02 mm2; C6, 8.98 ± 1.65 mm2; C7, 10.43 ± 1.86 mm2; and C8, 10.76 ± 2.02 mm2. Values for the brachial plexus were: upper trunk, 16.70 ± 2.88 mm2; middle trunk, 14.01 ± 2.70 mm2; and lower trunk, 13.75 ± 2.57 mm2. The side‐to‐side discrepancy was 11.91 ± 11.11%. Body mass index (BMI) and height correlated frequently with nerve CSA. Conclusions: These reference values may be helpful in investigating pathologies involving the cervical area. Muscle Nerve 46: 711–716, 2012