Ultrasonographic Study of Median Nerve According to Changed Wrist Position in Diabetics and Normal Subjects

BACKGROUND: To compare the diagnostic value between Phalen's test and reverse Phalen's test using a morphological change of the median nerve and the carpal tunnel in diabetics and normal controls seen by high-resolution ultrasonography and to research on an ultrasonography as an available tool for the screening and follow up aid-test of the carpal tunnel syndrome(CTS). METHODS: A cross-sectional area and a flattening ratio of the median nerve, and a cross-sectional area of the carpal tunnel were measured in neutral, maximally flexed(Phalen's test), and maximally extended (reverse Phalen's test) positions in 59 wrists of 30 normal controls and 60 wrists of 30 diabetics. RESULTS: 1) In controls and diabetics, the mean cross-sectional area of median nerve at the hamatum were 8.8/10.2 mm2, 8.0/9.5 mm2, 8.3/9.4 mm2, the mean flattening ratio were 3.0/3.0 mm2, 2.4/2.0 mm2, 3.2/3.0 mm2, the mean cross-sectional area of carpal tunnel were 176.5/197.7 mm2, 157.9/187.0 mm2, 170.6/192.5 mm2 in neutral, maximal flexion and maximal extension. 2) In controls, the cross-sectional area of median nerve and carpal tunnel were significantly decreased in maximal flexion(p<0.01), and in maximal extension(p<0.01). 3) In controls, the mean flattening ratio of median nerve was revealed significant change in maximal flexion(p<0.01), and in maximal extension(p<0.01). 4) In diabetics, the flattening ratio was significantly decreased in maximal flexion(p<0.01) with com- paring to neutral position. 5) In diabetics, the cross-sectional area of median nerve and carpal tunnel were significantly increased in all positions(p<0.05), and the mean flattening ratio of median nerve was similar to controls. CONCLUSION: In diabetics, increased cross-sectional area of median nerve can be explained by swelling of median nerve, also increased cross-sectional area of carpal tunnel is can be said to have taken place by the decreasing of the useful space in between the median nerve and carpal tunnel, this show that the diabetics have the high risk of the CTS. Phalen's test reveals higher degree of irritation to median nerve, The high-resolution ultrasonography is suggested as an available tool for the screening and follow up aid-test for the CTS

Ultrasonographic Study of Median Nerve according to Changed Wrist Position

OBJECTIVE: To compare the diagnostic value between Phalen's test and reverse Phalen's test using a morphological change of the median nerve and the carpal tunnel seen by high-resolution ultrasonography and to research on an ultrasonography as an available tool for the screening and follow up aid-test of the carpal tunnel syndrome (CTS). METHOD: A cross-sectional area and a flattening ratio of the median nerve, and a cross-sectional area of the carpal tunnel were measured in neutral, maximally flexed (Phalen's test), and maximally extended (reverse Phalen's test) positions in 59 wrists of 30 normal subjects. RESULT: The cross-sectional area of median nerve was significantly decreased in maximal flexion (p<0.01), and in maximal extension (p<0.01). The mean flattening ratio of median nerve was revealed significant change in maximal flexion (p<0.01), and in maximal extension (p<0.01). The mean cross-sectional area of the carpal tunnel was significantly decreased in maximal flexion (p<0.01), and in maximal extension (p<0.01), with comparing to neutral position, respectively. CONCLUSION: Phalen's test reveals higher degree of irritation to median nerve. The high-resolution ultrasonography is suggested as an available tool for the screening and follow up aid-test for the CTS.

Development of the Automatic Identifying Instrument for the Spinal Epidural Space

OBJECTIVE: To confirm practical usefulness of the newly invented automatic identifying instrument for the spinal epidural space. METHOD: Epidural block with blind approach has been done for the patients who suffered from lower back pain with radiating pain due to spinal disorders. Conventional blind approaches using the glass syringe (control group) and the newly invented instrument (experimental group) were applied to each 30 patients, respectively. Epidurography was used for the confirmation to conclude success or not. RESULTS: Two cases were failed in the control group. One case showed injected contrast media in the interspinal ligament, another case revealed dura-puncture. But there was no failure in the experimental group. The mean timefrom skin-penetration to epidurography was 299.7+/-13.6 second in control group and 184.0+/-16.3 second in experimental group. The mean time from changing to glass syringe (control group) or epidural detector (experimental group) to epidurography was 146.0+/-14.0 second in control group and 60.0+/-7.0 second in experimental group. The time for epidural block was much less in experimental group (p<0.001). CONCLUSION: This newly invented epidural detector could make the epidural block easier, safer, and faster. We suggest this instrument is useful complementary method for spinal epidural procedure.